Review Projects – 2013

Big Idea 2

Mr. Bennett

LO 2.1: The student is able to explain how biological systems use free energy based on empirical data that all organisms require constant energy input to maintain organization, to grow and to reproduce.

SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices.

Explanation: Life requires a highly ordered system to maintain homeostasis and allow organisms to continue biological function. As organisms use free energy, that energy is degraded in accordance with the 2nd Law of Thermodynamics. However, certain biological processes coupled with these entropy-increasing processes decrease entropy. For example, the conversion of ATP to ADP and the reverse reaction can be used to manage free energy within organisms. All organisms require a constant flow of free energy to maintain biological function, as this energy is used to regulate various processes in the body. For example, organisms must use energy in homeostasis to maintain a constant body temperature.

M.C. Question: Which of the following adaptations does NOT illustrate energy conservation within an organism?A) Large ears on the Fennec FoxB) A thickened cuticle on plant leavesC) American Black Bears hibernating through the winterD) Male emperor penguins huddling in large rotating masses during Antarctic wintersE) Changes in the E. Coli bacteria metabolism dependent upon the outside environment

Learning Log/FRQ-style Question: Over time, evolution has favored various methods of free energy capture in organisms. In plants, chloroplasts collect free energy from the sun and convert it to carbohydrates via the equation: 2 H2O + CO2 + light → carbohydrate (CH2O) + O2 + H2O. Suppose you are a scientist who wishes to conduct an experiment that will show how various environmental conditions can influence a plant’s ablility to capture free energy. If you wish to alter only the plant’s environment, what other variables need to be accounted for to ensure an accurate experiment?

http://www.accessexcellence.org/RC/VL/GG/ecb/ATP_ADP.php

LO 2.2: The student is able to justify a scientific claim that free energy is required for living systems to maintain organization, to grow or to reproduce, but that multiple strategies exist in

different living systems. SP 6.1: The student can justify claims with evidence.

EXPLANATION: All living organisms capture and store free energy to complete metabolism and other processes. Photosynthetic autotrophs convert solar energy into usable energy, whereas chemosynthetic autotrophs capture energy from small inorganic molecules and convert it into usable energy. All life depends on these processes, as heterotrophs are only able to obtain free energy from other organisms’ carbon compounds, transforming them into ATP through cellular respiration, whether it be anaerobic or aerobic. From a cellular perspective, different electron acceptors are used in various energy capturing processes—NADP+ in photosynthesis and oxygen in cellular respiration—thus exemplifying the multiple strategies exhibited in different living systems. The science practice can be applied through incorporating specific information from each process, such as including the fact that glycolysis occurs in the cytoplasm and produces ATP and pyruvate without using oxygen.

MULTIPLE CHOICE: Which of the following events occur during the light-independent reactions of photosynthesis?

I. Carbon gets reduced.II. ATP is produced.III. Oxidation of NADPH+ occurs.

A) I. onlyB) II. onlyC) I. and III. D) II. and III. E) I., II. and III.

LEARNING LOG: Describe in detail the difference between substrate level phosphorylation and oxidative phosphorylation in producing ATP. Then classify glycolysis as one or the other and explain why. Finally, discuss how glycolysis directly relates to the citric acid cycle.

LO 2.3 The student is able to predict how changes in free energy availability affect organisms, populations and ecosystems. SP 6.4 The student can make claims and predictions about natural phenomena based on different scientific theories and models.

Explanation: Life must be highly ordered. Order is maintained by the flow of free energy throughout a system. When energy or order is disrupted, organisms can die. Luckily, biological processes offset the increasing entropy and continually keep things in order. Although the 2nd law of thermodynamics states that entropy increases over time, biological systems do not defy this law because systems involve cellular processes that have negative changes in free energy, thus increasing entropy, and processes that have positive changes in free energy, which decreases entropy.Energy input must be higher than energy lost to entropy in order to be maintain cellular processes.

Energy pathways are sequential and may be entered at various places. (see Krebs Cycle, Fermentation, Calvin Cycle and Glycolysis). The energy produced can then be used in different metabolic functions in order to maintain normality. If there is energy leftover, that energy can either promote storage or growth in the organism. However, if there is a lack of energy then what is needed to maintain processes, the organism could undergo a loss in mass an eventually die.

Within an organism energy runs the metabolism and is essential in maintaining functioning processes. The metabolisms is made up of catabolic and anabolic reactions. Catabolic breaks down molecules and anabolic builds molecules. In endotherms, thermal energy from the metabolism is used in order to normalize an internal temperature. Ectoderms use outside heat to regulate body temperature. There is a relationship between metabolic rates and the size or an organisms. If an organisms is smaller it has a higher metabolic rate. In response to energy availability, an organisms has different methods of reproducing and rearing their offspring. Most plants and animals undertake in seasonal reproduction. If they were to reproduce at all times, they would not have enough energy to carry out all their biological processes. When differences in available energy occur in an ecosystem, it doesn’t justaffect the photoautotrophs but impacts every trophic level, which ultimately disrupts the ecosystem. M/C Question: If food is in short supply, which organism will feel the impact first?A) A catB) A mouseC) An elephantD) A wolf

Learning Log/FRQ-style Question: A certain ecosystem experiences a volcanic eruption that prevents any light from penetrating its dust clouds for a period of two weeks. What would be experienced by the autotrophs, primary consumers, secondary consumers.

LO 2.4: The student is able to use representations to pose scientific questions about what mechanisms and structural features allow organisms to capture, store, and use free energy.SP 3.1: The student is able to pose scientific questions.Explanation: Free energy refers to the portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system, such as in a living cell. Only a system that is not at equilibrium can spontaneously change, allowing it to perform work. The flow of free energy can be represented by an open hydroelectric system in which flowing water continues to drive a generator due to the fact that the intake and outflow of water inhibit the system from reaching equilibrium. Such examples include gravitational motion, diffusion, and chemical reactions (endergonic or exergonic). Free energy is involved in metabolism, as the energy released from a metabolic reaction can be harnessed to do work (cellular respiration and photosynthesis). Mechanisms such as Photosystems I and II, ATP synthase, the electron transport chain, and structures such as the mitochondria and chloroplasts are key in the capture, storage, and usage of free energy.

M.C. Question: Which of the following reactions does not result in the release of free energy?A) glycolysisB) ATP hydrolysisC) lactic acid fermentationD) Oxidative phosphorylation

Learning Log/FRQ Question:The light reactions of photosynthesis can be represented by a “molecular mill,” to which it issometimes referred. Describe the flow of free energy throughout the light reactions and be sureto include details regarding the production of ATP through ATP synthase.

LO 2.5: The student is able to construct explanations of the mechanisms and structural features of cellsthat allow organisms to capture, store or use free energy.

SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices.

Explanation: Autotrophs and heterotrophs capture free energy in differing ways. Autotrophs capture it through their physical sources in the environment while heterotrophs capture it through carbon compounds produced by other organisms. NADP+ in photosynthesis and oxygen in cellular respiration foster the way organisms capture, store, and use free energy. Light reactions are the steps of photosynthesis that convert solar energy to chemical energy. During photosynthesis, chlorophylls absorb free energy from light, boosting electrons to a higher energy level in Photosystems I and II. Cellular respiration occurs when oxygen is consumed as a reactant along with the organic fuel. Cellular respiration also involves in a series of coordinated enzymecatalyzed reactions that harvest free energy from simple carbohydrates. Glycolysis, pyruvate, and the Krebs cycle essentially leads ATP which is synthesized from ADP. Free energy becomes available for metabolism by the conversion of ATP→ADP, which is coupled to many steps in metabolic pathways.

Learning Log/FRQ-style Question: The two stages of photosynthesis are known as the light reactions and the Calvin cycle. Identify and explain the steps within each of the stages and how light reactions and the Calvin cycle work together. Then describe the connection between photosynthesis and cellular respiration within plants.

M.C. Question: All of the following statements about glycolysis are true EXCEPT A) glycolysis has steps involving oxidation-reduction reactions. B) the enzymes of glycolysis are located in the cytosol of the cell. C) glycolysis can operate in the complete absence of O2. D) the end products of glycolysis are CO2 and H20.E) glycolysis makes ATP exclusively through substrate-level phosphorylations.

LO 2.6: The student is able to use calculated surface area-to-volume ratios to predict which cell(s) might eliminate wastes or procure nutrients faster by diffusion.SP 2.2: The student can apply mathematical routines to quantities that describe naturalphenomena.Explanation: In order for a cell to eliminate wastes and procure nutrients faster, it needs a larger surface area because it is the cell membrane that allows for these objects to pass through. The cell also needs a volume as small as possible so that energy is not used to fuel itself which would increase the use of the nutrients and increase the amount of waste produced and excreted. This is why a higher surface area-to-volume ratio is more ideal in organisms.M.C. Question: Which would be more beneficial to a cell?A. Having a small surface area and a large volume.B. Having a small surface area and a small volume.C. Having a large surface area and a small volume.D. Having a large surface area and a large volume.Learning Log/FRQ-style Question: How and why would evolution favor organisms that develop structures like the root hairs shown in the picture or like the cells of the villi that line humans intestines? What would be the consequences to the organisms if they did not develop these structures?

Image provided by Bing

LO 2.7 Students will be able to explain how cell size and shape effect the overall rate of nutrient intake and the rate of waste elimination

SP 6.2 The student can construct explanation of phenomena based on evidence produced through scientific processes.

Explanation: Oxygen, nutrients, and waste pass through the plasma membranes of all types of cells. When it comes to the cell size and shape affecting the overall rate of nutrient intake and waste elimination, there is a direct correlation between the area (in square micrometers) of the membrane and the amount of the particular substance that can pass through or be excreted. The makeup and polarity of the substance moving through the membrane is significant and the phospholipid bilayer structure of the plasma membrane can interfere with the transport of the substance. A significantly high ratio of volume to surface area is essential for cells to exchange materials with their external surroundings; ex: intestinal cells. Size relates to function, the rate of cellular metabolism sets a limit on size; cells need to have the proper equipment and the necessary amount of space to carry out functions such as waste excretion and nutrient intake.

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LO 2.7 Multiple Choice Question: The cells of an ant and an elephant are, on average, the same size; an elephant just has more cells. What is the main advantage of small cell size?A. Small cell has larger plasma membrane surface area than does a larger plasma

membrane surface are than does a large cell, facilitating the exchange of sufficient materials with its environment.

B. A small cell has a larger plasma membrane surface area than does a large cell, facilitating the exchange of sufficient materials with its environment.C. A small cell has a smaller cytoplasmic volume relative to its surface area, which helps to ensure the exchange of sufficient materials across its plasma membrane.D. Small cells require less oxygen than do large cells.

Free Response/Learning Log Question: Explain in detail why there would be both upper and lower limits to the size of a cell.

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LO 2.8: The student is able to justify the selection of data regarding the types of molecules that an animal, plant or bacterium will take up as necessary building blocks and excrete as waste products.

SP 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific question.

Explanation: Animals, plants, and bacteria take up a variety of molecules including Nitrogen, Carbon, Water, Carbon Dioxide, Glucose, Oxygen, Phosphorous, Salt, Potassium, and Calcium

(to name a few of the most important). The basis for determining the importance of these molecules , their placement, and their role in an organism can stem from a variety of scientific procedures such as experimental investigation, or historic reconstruction. However, in regards to the composition of an organism (the importance of these molecules as building blocks, rather than in chemical or mechanical processes) the most important type of data comes from the culmination of past and present scientific observation , and the ability to take these separate observations and combine them into fully-realized conclusions.

The justification of the selection of data regarding the types of molecules taken up by various organisms can be more easily explained by depicting a common, yet elaborate, example: the uptake of water in plants. The conclusion that scientists have come to is that the transpiration of water from the leaves pulls water upward from the roots, through the xylem in the plant, and this allows the water to be dispersed throughout the plant and used for a variety of growth (or other) processes which require water either directly, or as a means of transport for solutes. But how did scientists come to this conclusion, and what data was important to this?

After various observations, scientists were able to extract important data, which at the time might have been conducted independently of the plant transport example, but would then be selected for use in developing the understanding of water transport in plants. The basis of this was observation regarding the properties of water. After observing and recording various characteristics that were possible because of molecular composition of water, they were able to give water unique properties such as cohesion due to hydrogen bonding (helps hold together the column of water within the xylem) and adhesion (helps water adhere to the cell walls and resist gravity). Further experimental and observational testing in regards to osmosis, water potential, diffusion, gradients, evaporation, ATP, etc. would have to be conducted, but these individual snippets of data could then be selected to support the big idea of water transport, which is crucial to the build up of all complex molecules in living organisms. This “cumulative observation” method is a crucial part of analyzing the role of variety of molecules as building blocks or waste products in plants, bacteria, and animals.

MC Question: Johnny is a young boy, but he loves to conduct experiments, because he wants to be a scientist when he grows up. For his latest experiment, he wants to test the impact of a light breeze on the growth of a species of water plant. He purchases three bowls to place the seeds inside, and two small fans to create the breeze; one plant will be his control and the other 2 will be his experimental plants. He places both plants in the same room under almost identical conditions, places the fans the same distance from each of the experimental plants, and fills the three bowls with the same amount of water. However, halfway through filling the bowl for his control plant, he runs out of distilled water and finishes filling it with tap water. After this, he turns the fans on low, and lets the plants grow for one week, before taking his first measurement and recording it. Is Johnny’s first measurement a justifiable selection of data?a) Yes, all of the conditions are almost identical, and tap water in the control will not affect the outcome because the plant will take up the water regardless.b) No, the tap water contains more solutes than distilled water, so the water potential of the water outside the plant in the control bowl will be higher than it should be, and the plant will take

up water more quickly.c) No, the tap water contains more solutes than distilled water, so the water potential of the water outside the plant in the control bowl will be lower than it should be, and the plant will take

up more slowly.d) Yes, even though there are more solutes in the tap water, they will not make it past the selectively permeable Casparian strips.e) No, the tap water will definitely be toxic to the plants.

FRQ Question: Explain how the light reactions and the Calvin cycle of photosynthesis work together to nourish a plant with the necessary sugar, and describe the role of each of the following molecules in a plant as either a building block, or waste product.

a)H20b)O2c)CO2d)Sugar

LO 2.10: The student is able to use representations and models to pose scientific questions about the properties of cell membranes and selective permeability based on molecular structure.

SP 1.4: The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.SP 3.1: The student can pose scientific questions.

Explanation: Membranes are composed of a phospholipid bilayer that is amphipathic. Membranes are selectively permeable due to the amphipathic phospholipids that form a cell membrane. Non-polar particles, such as steroids, can pass through the membrane easily and are selected for. Large, polar, charged molecules are selected against (like glucose, amino acids, and ions). Membranes are held together mostly by hydrophobic interactions, which are weaker than covalent bonds, which contributes to the fluidity of the membrane. If the membrane is composed of phospholipids with unsaturated carbon tails, then it will remain fluid to a lower temperature due to the kinks in the tails, which keep the phospholipids from packing as close together. Cholesterol also controls fluidity by moderating it. In colder temperatures, cholesterol keeps phospholipids spaced out, keeping them more fluid, but in hotter temperatures, it gets in the way and restrains movement, keeping them less fluid. Lipids in the membrane move laterally about 107 times per second. Also, various proteins are embedded in or attached to the membrane; the alpha helix holds integral proteins in the membrane. Transport proteins help hydrophilic substances enter the cell. An example of this is the aquaporins that help transport water into the cell.

M.C. Question: A plant cell starts off in an isotonic solution with 20 water molecules, 15 sodium molecules, 15 glucose molecules, and additional molecules necessary for photosynthesis. After completing photosynthesis, the plant cell still has the 20 water molecules and 15 sodium molecules, but now it has 30 glucose molecules. Do not account for the change in concentrations of the molecules needed for photosynthesis. What happens to the movement of water and other materials into and out of the cell?

A) 15 glucose molecules leave the cell to create an isotonic environment again.

B) 15 sodium molecules leave the cell to create an isotonic environment again.

C) With help from aquaporins, 15 water molecules enter the cell to balance out the increased glucose concentration with the cell.

D) The cell is a plant cell and has no plasma membrane for water and other materials to move in and out of.

Learning Log/FRQ-style Question: Suppose you place a cell in a colder environment. a). What does this environment do to the membrane’s fluidity? Why? b). Draw what the phospholipids in the membrane would look like. c). Explain the ways that membranes remain fluid in spite of temperature changes. d). Explain the importance of membrane fluidity with regards to selective permeability. e). Hypothesize ways that cells might evolve in warmer and colder environments if their membranes no longer had cholesterol.

LO 2.11: The student is able to construct models that connect the movement of molecules across membranes with membrane structure and function.SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.SP 7.1: The student can connect phenomena and models across spatial and temporal scales.SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas.Explanation: Cell membranes exist to separate the internal environment of a cell from the external environment. Plasma membranes accomplish this through their unique selective permeability. The physical structure of the membrane allows some molecules to enter and exit, while preventing the passage of others. The phospholipid bilayer prevents polar molecules from diffusing across the membrane, while nonpolar molecules,such as steroids, can penetrate the bilayer. To allow for the passage of larger molecules and polar molecules, integral proteins stud the surface of the membrane. Their structure dictates which substances can be transported across the membrane, with the concentration gradient in passive transport or against it in active transport.

Multiple Choice Question:In a U-tube such as the one in the diagram to the right, the concentration of solutes in the left side X is 2M Sucrose and 1M Glucose while the concentration on the right side Y is 1M Sucrose and 2M Glucose. Note: The membrane pores are only permeable to Glucose.After the system reaches equilibrium, what changes are observed?a. The water level is higher in side X than in side Y.b. The water level is higher in side Y than in side X.c. The water level is unchanged. d. The molarity of sucrose and glucose are equal on both sides.e. The molarity of glucose is higher in side X than in side Y.

FRQ:Cell membranes separate the internal environment of a cell from the outside environment.a) Explain why small plants or animals often die after a winter freeze. Be sure to include the effects of water crystallization on plasma membranes.b) Create a diagram and explain how the Casparian strip blocks the passive flow of dissolved materials into the interior of a plant. The Casparian strip is composed of hydrophobic suberin.

Lo 2.12 The student is able to use representations and models to analyze situations or solve problems qualitatively and quantitativley to investigate whether dynamic homeostasis is maintained by the active movement of molecules across membranes.SP 1 .4 Evidence of student learning is a demonstrated understanding of each of the following:1. Passive transport plays a primary role in the import of resources and the export of wastes. Explanation Passive transport does not require the input of metabolic energy; the net movement of molecules is from high concentration to low concentration.Active transport requires free energy to move molecules from regions of low concentration to regions of high concentration.The processes of endocytosis and exocytosis move large molecules from the external environment to the internal environment and vice versa, respectively.Multiple choice The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are ?A. LipidsB. Carbohydratesc. Nucleic AcidsD. Integral membrane proteinsLearning Log Question/ FRQ style question Using a diagram describe the fluid-mosaic model of the cell membrane. Indicate the following; phospholipid molecules, hydrophobic and hydrophilic ends, types of membrane proteins and glycoproteins. List substances to which the membrane is relatively permeable and those substances to which it is relatively impermeable.

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LO 2.12 Key Concepts:• 1. Small, uncharged polar molecules and small non-polar molecules, such as N2, freely pass across

the membrane. Hydrophilic substances such as large polar molecules and ions move across the membrane through embedded channel and transport proteins. Water moves across membranes and through channel proteins called aquaporins.

• 2. Passive transport does not require the input of metabolic energy; the net movement of molecules

is from high concentration to low concentration. • Passive transport plays a primary role in the import of resources and the export of wastes. • 3. Membrane proteins play a role in facilitated diffusion of charged and polar molecules through a

membrane from low concentration to high concentration.

• 4. Membrane proteins carry out active transport, which requires free energy (often in the form of ATP) to move molecules from regions of low concentration to regions of high concentration.

• 5. External environments can be hypotonic, hypertonic compared to internal environments of cells. As a result, a concentration gradient is present that will influence movement of water and solutes. As well, equilibrium exists when the external environment is isotonic to the internal environment of a cell.

• 6. The processes of endocytosis and exocytosis move large molecules from the external

environment to the internal environment and vice versa, respectively.

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• LO 2.13: The student is able to explain how internal membranes and organelles contribute to cell functions.

• SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices.

• Explanation: The internal membranes of cells allow for greater surface area for reactions to take place and also offset competing interactions, thus facilitating cell processes. In eukaryotic cells, membrane bound organelles provide specific locations for metabolic processes and enzyme reactions to take place. The Golgi apparatus acts as the packaging and shipping center for the cell by packaging macromolecules for transport elsewhere in the cell. The rough Endoplasmic reticulum makes membrane and secretory proteins, while the smooth ER is involved in lipid and carbohydrate synthesis. Chloroplasts, found only in plants, are the site of photosynthesis. Mitochondria are the power houses of cells because they generate most of the cell’s supply of ATP. The nuclear envelope is the double layer membrane that surrounds the nucleus of eukaryotic cells. Ribosomes can either be free floating or attached to the rough ER and are responsible for protein translation. The scientific study of cells and discovery of microscopes makes understanding the cell and its components possible.

• MC Question: Which of the following statements is/are true?A) Smooth ER is abundant in cells that synthesize large amounts of lipidsB) Chloroplasts have their own DNA, while mitochondria do notC) Molecules travel from the rough ER to the Golgi apparatusvia vesicles that break off the ER and fuse to the GolgiD) Both A and C are trueE) A, B, and C are true

• FRQ Question: Your cousin was recently diagnosed with a mitochondrial disease that is causing his mitochondria to deteriorate quickly. The doctors have told him that his mitochondria may be completely nonfunctional within a few years. What is likely the result of this disease? Will his cellsstill be able to carry out passive transport without enough ATP?

Learning Objective 2.14The student is able to use representations and models to describe differences in prokaryotic and eukaryotic cells.

Connect Science Practices1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.

The objective intends to make sure that the student is able to identify and explain the function of various parts of the two major kinds of cells. This shows an understanding of the differences between the two types of the cells and what their function is.

Multiple Choice QuestionUsing figures 1.1 and 1.2, identify the function of the cell part labeled in each figure. a. I is used for transcription and II is used to store

genes. b. I is used for cellular respiration and II is used

for gene storagec. I is used to facilitate diffusion and II is used for

protein synthesisd. I is used for endocytosis and II is used for fluid

storagee. I is performs dehydration reactions and II is

used to filter the cytoplasm.

Figure 1.1 Figure 1.2

I II

Learning Log Style Question:Figure 1.1 is a liver cell and figure 1.2 is a Escherichia coli cell. Describe 3 distinct differences between these two different kinds of cells.

LO 2.15 The student can justify a claim made about the effect(s) on a biologicalsystem at the molecular, physiological or organismal level when given a scenarioin which one or more components within a negative regulatory system is altered

SP 6.1The student can justify claims with evidence.

Explanation: Mechanisms of homeostasis moderate changes in the internal environment of an organism. Homeostasis in organisms is maintained through a negative feedback loop. In a negative feedback a receptor detects a change in some variable in the internal environment. The signal received by the receptor is then interpreted by the “control center” and directs an appropriate response known as the effector. An example of negative feedback at work is thermoregulation. For example, in thermoregulation, when heat detecting cells detect an increase in body temperature a signal is sent to the hypothalamus. The hypothalamus activate the body’s thermostat, which is part of the nervous system, which in turn opens sweat glands and expands blood flow to the skin to increase heat radiation. The cooling of the internal environment in turn shuts off the thermostat in the hypothalamus to maintain homeostasis

Multiple Choice:What physiological change might occur in an individual if there is an inhibition of ADH?A. The individual would experience an increase in urination because of lack of reabsorption in the

kidney tubules.B. The individual would not feel the need to rehydrate because inhibition of ADH results in water

reabsorption. C. Inhibiting ADH would cause an individual to feel dehydrated as there would be an increase in water

loss through urination resulting in “hangover” like symptoms D. A and CE. A, B, and C

Frq style question:Using specific evidence justify the following claim. Why is that individual who consume alcohol experience water loss in urine instead of reabsorbing water back into the blood stream?

Thermoregulation

LO 2.16: The student is able to connect how organisms use negative feedback to maintain their internal environments.SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/ or across enduring understandings and/ or big ideas.

Explanation: Mechanisms of homeostasis moderate changes in the internal environment. Any homeostatic control system has three functional components: a receptor, a control center, and an effector. The receptor detects a change in some variable of the organism’s internal environment, such as a change in body temperature. The control center processes information it receives from the receptor and directs an appropriate response by the effector. For example, when the room temperature falls below a “set point”, the thermostat switches on the heater (the effector). When the thermostat detects a temperature above the set point, the thermostat switches the heater off. This control circuit is called negative feedback because a change in the variable being monitored (in this case temperature) triggers the control mechanism to counteract further changes in the same direction. Negative feedback mechanisms prevent small changes from becoming too large.M.C. Question: All of the following internal variables are moderated by negative feedback circuits EXCEPTA) Blood pressureB) Respiration rateC) Uterine contractions D) Blood glucose levelLearning Log/ FRQ- style Question: Antidiuretic hormone (ADH) enhances fluid retention by making the kidneys reclaim morewater. Discuss how negative feedback circuitsregulate water balance in kidneys. Be sure to reference specific endocrine glands in your response.

LO 2.17: The student is able to evaluate data that show the effect(s) of changes in concentrations of key molecules on negative feedback mechanisms.

SP 5.3: The student can evaluate the evidence provided by data sets in relation to a particular scientific question.

Explanation: A negative feedback mechanism is one in which a change in a monitored physiological variable triggers a response that counteracts the initial fluctuation, returning the physiological variable to its homeostatic state. Most organisms use homeostasis through negative feedback to regulate necessary concentrations of key molecules in their internal environments. In negative feedback, the response, or end product, is connected to and directly controls the initial stimulus. For example, in cellular respiration, ATP is constantly being produced via glycolysis, the citric acid cycle, and oxidative phosphorylation. However, when there is plenty of ATP for a cell to access, a negative feedback mechanism uses ATP to allosterically bind to phosphofructokinase to inhibit glycolysis. Conversely, when the ATP concentration is too low, a negative feedback mechanism will use AMP to allosterically activate phosphofructokinase and glycolysis.

M.C. Question: A pharmaceutical company is testing the impact of different chemicals on Graves’ disease, or hyperthyroidism. Graves disease results from the inhibition of the negative feedback mechanism of the thyroid gland, which produces T₃ and T₄ hormones. Which of the following chemicals best stimulates the negative feedback mechanism, effectively combating Graves’ disease. Assume all chemicals are tested on a patient with the same homeostatic T₄ concentration of 6.7 micrograms per deciliter (mcg/dL).

FRQ-style Question: Use the given figure as a reference.a) Suppose you have just eaten a carbohydrate-rich meal. I Identify the stimulus on blood glucose. II Describe the body’s response to the stimulus.b) Suppose you have just skipped a meal. I Identify the stimulus on blood glucose. II Describe the body’s response to the stimulus.

Chemical Initial T₄ Concentration (mcg/dL)0 hrs

T₄ Concentration (mcg/dL) 1hour

T₄ Concentration (mcg/dL) 2 hours

T₄ Concentration (mcg/dL) 3 hours

T₄ Concentration (mcg/dL) 4 hours

A 13.8 11.5 8.4 5.2 2.8

B 13.8 14.5 14.9 15.6 16.0

C 13.8 13.6 13.4 13.2 13.0

D 13.8 11.1 9.5 7.2 6.8

E 13.8 13.8 13.9 14.0 14.1

A) A B) B C) C D) D E)E

LO 2.18 The student can make predictions about how organisms use negative feedback mechanisms to maintain their internal environments.

SP 6.4 The student can make claims and predictions about natural phenomena based on scientific theories and models.

Explanation Negative feedback mechanisms maintain dynamic homeostasis for a particular condition (variable) by regulating physiological processes with specific hormones, returning the changing condition back to its target set point- such as with glucose or calcium regulation in the blood. A change in the variable being monitored triggers the control mechanism to counteract further change in the same direction.

M.C. Question Which of the following is not an example of negative feedback?A) Maintaining the calcium in the blood through calcitonin and parathyroid hormonesB) Regulating glucose levels with insulin and glucagon hormones C) Thermoregulation, in order to stay within a tolerable rangeD) Uterine contractions during childbirth through oxytocinE) Control pathways with the thyroid glands or adrenal glands

FRQ Question a. Pancreatic hormones, as mentioned above, help regulate the calcium levels in the blood. Identify and describe two pancreatic hormones and

their roles in the blood calcium homeostasis. b. Your Uncle Calcio has a vitamin D deficiency, describe the changes in the process of calcium regulation?

http://www.studyblue.com/notes/note/n/hormones/deck/5163934

LO 2.19: The student is able to make predictions about how positive feedback mechanisms amplify activities and processes in organisms based on scientific theories and models.

SP 6.4: The student can make claims and predictions about natural phenomena based on scientific theories and models.

Explanation: Positive feedback is a mechanism used to trigger an organism’s response to internal and external changes in their environment. The response could be behavioral or physiological. It involves a change in some variables that trigger mechanisms that amplify rather than reverse the change. Positive feedback mechanisms are one directional, meaning that one (or a few) of something stimulates the creation of more of the same thing. For example: The hormone oxytocin stimulates and enhances labor contractions. As the baby moves towards the birth canal it creates pressure (contraction) on pressure receptors in the uterus that evoke the release of oxytocin from the brain. Once these hormones reach the uterus they stimulate the pressure receptor, amplify the release of oxytocin and consequently induce labor. So, the release of oxytocin triggers the release of more oxytocin, therefore amplifying its concentration.

M.C. Question: Which of the following processes has a positive feedback mechanism?

a. Heating and cooling a house.b. Placing a banana in a brown paper bag.c. A Pancreas releasing insulin.d. Shivering.Learning Log/FRQ-style Question: Timmy was racing his friend

down the road when he fell and a rock created a gash in his knee. What inflammatory response would follow this incident which exemplifies a positive feedback mechanism? What would happen if this response did not occur?

LO 2.20 The student is able to justify that positive feedback mechanisms amplify responses in organisms.

SP 6.1 The student can justify claims with evidence.

Explanation: Positive feedback is a physiological control mechanism in which a change in some variable causes a response that amplifies the response rather than reverse it. Childbirth is an example of positive feedback. The pressure of the baby’s head pushes against the receptors near the opening of the uterus. This pressure stimulates uterine contractions that releases oxytocin which then stimulates more contractions creating greater pressure on the uterus which leads to childbirth. M.C. Question: Which of the following responses is an example of positive feedback?a.After eating your body begins to produce pepsin which stimulates other proteins in the body to produce more pepsin. b.After eating a glucose rich meal your pancreas secretes insulin to lower the blood glucose concentration.c.After running your begin to sweat in order to cool your body down. d.Producing more red blood cells, which transport oxygen from the lungs to the organs, because of a low concentration of oxygen.

Free Response Question: After your friend Sara accidentally cuts her finger you inform her not to worry because her blood will start to clot and she then informs you she is a hemophiliac. Explain the normal positive feedback response that would occur in a non hemophiliac individual. Identify the receptor, control center and effector in this response and explain their role in feedback mechanisms.

LO 2.22 The student is able to refine scientific models and questions about the effectof complex biotic and abiotic interactions on all biological systems, from cells and organisms to populations, communities and ecosystems.

SP 1.3 The student can refine representations and models of natural or man madephenomena and systems in the domain.SP 3.2 The student can refine scientific questions.

Explanation: Abiotic factors, such as climate, temperature, and precipitationeffect the specific organisms that live in each biome. The energy flow in a community depends on primary productivity as energy is then transferred toeach trophic level above. Energy flows from autotrophs to primary consumers,then to heterotrophs. While autotrophs depend on sunlight, water, and nutirents for survival, heterotrophs gain their energy through predator-prey relationships. Available land and resources, or the lack thereof, cause competition among the population in the struggle for survival.

Which of the following organismsgains 10% of the energy originallyretained from the autotroph?A. GrasshopperB. MouseC. LizardD. A and B

MC:

FRQ Question:Identify all forms of symbiotic relationships

and give and example for each.

LO 2.23 The student is able to design a plan for collecting data to show that all biological systems (cells, organisms, populations, communities and ecosystems) are affected by complex biotic and abiotic interactions. SP 4.2 The student can design a plan for collecting data to answer a particular scientific questionSP7.2 The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas.

• Explanation- Growth, reproduction and maintaining organization require free energy and matter, and organisms use biotic factors to reproduce, and maintain energy to keep up a species. Autotrophs capture free energy from sources in the environment and photosynthetic organisms capture free energy present in sunlight, an abiotic factor. Organisms exchange matter with the environment to grow reproduce and maintain themselves. Molecules and atoms are exchanged with the area around the given group, and new molecules are created. Communities are composed of populations of organisms that interact in complex ways by the diversity and factors that limit or support growth in an ecosystem. As limits to growth due to density-dependent and density-independent factors are imposed, a logistic growth model can be made to track the population. Interactions among cells of a population of a unicellular organism can be similar to those of multicellular organisms, and these interactions lead to more use of energy and matter.

• MC Question- Which of the following reproductive action would you expect from a fish in shallow water that is hypersensitive to light and predators, when there is a scarcity of food and weather is turbulent?

• A) The fish would move out to deeper water, in order to find food, and reproductive success would increase• B) The fish would remain in its habitat and abstain from reproduction because of the food scarcity• C) The fish’s reproductive success would plummet and the population size would decrease constantly• D) No change in behavior or population size would occur• E) Both A and C

• Learning log Question- Explain the difference between 3 different types of marine biomes and their interactions with species that inhabit those regions.

Rain shadow effect

LO 2.24 The student is able to analyze data to identify possible patterns and relationships between biotic or abiotic factor and a biological system (cells, organisms, populations, communities, or ecosystems). SP 5.1 The student can analyze data to identify patterns or relationships. Explanation: Both biotic and abiotic factors greatly impact all levels of biological organization. For example, in the level of an ecosystem, you have a community in which biotic organism populations help one another. Fish of all different species interact to keep a waterfront alive. Not only can biotic components help a community, but many abiotic factors such as a natural disaster or climate change can impact a population. As humans advance in technology and continue to only think of their needs when addressing ecosystems, devastating results may occur to the balance between both biotic and abiotic components which can ultimately impact the entire biosphere. M.C Question: Which of the following is an example of an abiotic factor at work? A) A deadly virus that mutates every 30 seconds and destroys vital body organs. B) A storm generating an enormous tidal surge at 6 meters in height, inundating thousands of acres of coastal marshland. C) A decomposing body being broken down by bacteria. D) A swarm of locus in the gregarious phase devastate crops and cause major agricultural damage. Learning Log/FRQ-style Question: Using the graph provided, list TWO abiotic factors and ONE biotic factor that could have contributed to the population fluctuation of the New Orleans population. Be thorough with each example.

In 2005, the alligator population in New Orleans decreased significantly.

A virus such as HPV can reduce the survival rate of an organism such as a human.

LO 2.25 The student can construct explanations based on scientific evidence that homeostatic mechanisms reflect continuity due to common ancestry and/or divergence due to adaptations in different environments.SP 6.2 The student can construct explanations of phenomena based on evidence producedthrough scientific practices.Explanation: Millions of years ago, the environment changed and created a drier environment which coaxed some aquatic plants to adapt and develop a different way to exchange gases. Instead of having aerenchyma like the aquatic plants, the new terrestrial plants developed stomata to obtain CO2 and lose water. The continuity of homeostatic mechanisms is demonstrated by common ancestry, but can be susceptible to change based on the response to different environmental conditions. With fish being one of the first organisms on the earth, once areas began to become deficient of water they were forced to grow lungs in addition to having gills so they could breathe air. Eventually the amphibians evolved into mammals which allowed them to live on land full time. The adaptations to the circulatory systems of amphibians and mammals because of the changes to their environments proves their common ancestry with fishes.MC: The lungs that amphibians and mammals developed in order to breathe on land are an example of what in relation to a fish’s gills?A.) a vestigial organB.) a homologous structureC.) an analogous structureD.) convergent evolutionFRQ/Learning Log/Short Answer: How does osmoregulation occur in most marine animals? Freshwater? Land?

Learning objective 2.27 The student is able to connect differences in the environment with the evolution of homeostatic mechanisms. Science practice 7.1 The student can connect phenomena and models across spatial and temporal scales.Explanation: Changes in an organism’s environment cause individuals with favorable mutations to be selected over individuals without the favorable mutations by enabling the favorably mutated individuals to reproduce more frequently and with greater success. This phenomenon is called natural selection. Natural selection occurs in homeostatic mechanisms quickly when a change in a population’s environment occurs. For example, if an arid area is experiencing a severe drought, individuals in the population with a mutation that allows them to conserve water will be more likely to survive and reproduce than individuals without the mutation. Then, members of the next generation with a more developed ability to conserve water will be more likely to reproduce, enacting directional selection on the population towards individuals that can conserve water and changing or developing the specie’s homeostatic mechanism for water use. Also, in accordance with SP 7.1, there should be a clear connection between this concept and a graph of a species’ ability to conserve water over time.

MC: The habitat of a species of rabbit has a particularly cold winter six years in a row. Which is most likely to happen to the rabbits?A. Stabilizing selection because the rabbits of small and large sizewill be more commonly preyed upon. B. Divergent selection because rabbits with medium color fur willnot blend into their environment well.C. Directional selection because rabbits with thicker fur will have higher survivorship and reproductive success. D. The rabbits will likely die because of a lack of food.

FRQ: Explain in detail the effect of a steady increase in temperature of a desert environment on a species of lizard. Why would this occur? What effects would it have on the species in the future?

LO 2.29 The student can create representations and models to describe immune responses. 1.1 The student can create representations and models of natural or man-made phenomena and systems in the domain.1.2 The student can describe representations and models of natural or man-made phenomena and systems in the domain.

Plants, invertebrates and vertebrates have multiple, nonspecific immune responses.Examples:Invertebrate immune systems have nonspecific response mechanisms, but they lack pathogen-specific defense responses. Plant defenses against pathogens include molecular recognition systems with systemic responses; infection triggers chemical responses that destroy infected and adjacent cells, thus localizing the effects.Vertebrate immune systems have nonspecific and nonheritable defense mechanisms against pathogens.Mammals use specific immune responses triggered by natural or artificial agents that disrupt dynamic homeostasis. The mammalian immune system includes two types of specific responses: cell mediated and humoral. In the cell-mediated response, cytotoxic T cells, a type of lymphocytic white blood cell, “target” intracellular pathogens when antigens are displayed on the outside of the cells. In the humoral response, B cells, a type of lymphocytic white blood cell, produce antibodies against specific antigens. Antigens are recognized by antibodies to the antigen. Antibodies are proteins produced by B cells, and each antibody is specific to a particular antigen. A second exposure to an antigen results in a more rapid and enhanced immune response. M.C. Question: Why can normal immune responses be described as polyclonal? A) Blood contains many different antibodies to many different antigens. B) Construction of a hybridoma requires multiple types of cells. C) Multiple immunoglobulins are produced from descendants of a single B cell. D) Diverse antibodies are produced for different epitopes of a specific antigen. E) Macrophages, T cells, and B cells all are involved in normal immune response.

Describe the main role of each of the following cell types, once it is activated by antigens and cytokines: helper T cells, cytotoxic T cells, and B cells.

LO: 2.30: The student can create representation or models to describe nonspecific immune defenses in plants and animals. SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.

SP 1.2: The student can describe representations and models of natural or man made phenomena and systems in the domain.

Explanation: The nonspecific immune response is an innate defense that quickly recognizes and responds to a broad range of microbes regardless of their identity. This immunity consists of external barriers (skin, mucous membranes) as well as internal cellular and chemical defenses which fight infectious agents that breach the external barriers. The main players in the internal defenses are macrophages and other phagocytic cells, which ingest and destroy pathogens.

M.C. Question: Which of the following serve as examples of internal nonspecific immune responses?A) PhagocytosisB) Mucous membranesC) Natural killer cellsD) A & BE) A & C

Learning Log Question: You were slicing an apple, and accidentally cut your finger. Discuss the inflammatory response that would occur in response to the cut on your finger (use the following: macrophage, blood clotting, pathogens, chemokines, etc.). The cut in infected with a bacterial infection. Discuss how it may induce a systemic response that can lead to septic shock.

LO 2.31: The student can connect concepts in and across domains to show that timing and coordination of specific events are necessary for normal development in an organism and that these events are regulated by multiple mechanisms.

SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas.

Explanation: Although treating biological microprocesses as isolated actions is an ideal way to study cellular operations, treating processes as disconnected is often unrealistic given the plethora of mechanisms that act simultaneously in complex organisms. One example of such a relationship is apoptosis (below, right), or cellular suicide. Apoptosis, protecting an organism from infections and cancerous growths, is critical to development, occurring tens of millions of times per day in humans. A variety of physical and chemical components—including radiation and stress or hormone, cytokine, and T cell interactions—can either inhibit or induce apoptosis. On a larger scale, specialized but related cell groups—such as myocytes, red blood cells, and neurons—must work cohesively via both physical and biological means to carry out operations (for example, neurons communicating with muscle cells in the legs allow an organism to run while red blood cells ensure fluid circulation of oxygen throughout the circulatory system).

M.C. Question: Exposure to certain types of ultravioletradiation can degrade the spindle fibers in meiotic cells. If an animal cell in prophase I was irradiated with this type of radiation but went on to fertilize a gamete, which of the following would most likely afflict the resultant offspring?A) Red-green color blindnessB) Huntington’s diseaseC) Klinefelter syndromeD) Multiple sclerosisE) Human immunodeficiency virus

Learning Log/FRQ-style Question: Biologists studying thigmomorphogenesis, a type of physical change in plants induced by mechanical stress, notice that the plants raised inside a greenhouse grow taller and skinnier than plants of the same species outside, even when both groups receive identical sunlight, water, weather exposure, and nutrients. What environmental conditions might have induced thigmomorphogenesis outside of the greenhouse? Why might natural selection continue to favor thigmomorphogenetic plants?

LO 2.33:The student is able to justify scientific claims with scientific evidence to show that timing and coordination of several events are necessary for normal development in an organism and that these events are regulated by multiple mechanisms. [See SP 6.1] SP 6.1:The student can justify claims with evidence.

Explanation: The timing and coordination of molecular, physiological and behavioral events are essential for the normal development of an organism. Induction, for example, causes changes in an organism’s gene expression resulting in observable cellular changes. Due to this, interactions between embryonic cells eventually induce differentiation of the many specialized cell types. The end product is a new organism. Evidence is shown by mutations such as insertion, deletion, substitution- all of which result in abnormal development. Other evidence of this is manifested through the genetic regulation by microRNAs; they play a key role in the development of organisms and the control of cellular functions. RNA transcripts from miRNA-encoding genes are processed into miRNAs, which prevent expression of complementary mRNAs.

Multiple Choice:

Which of the following is true of apoptosis during the development of mammals?

A) Apoptosis eliminates the cells in the interdigital regions, thus forming the digits.

B) Cancers result from a failure of cell suicide.

C) A built-in cell suicide mechanism is essential for normal growth and development.

D) The action of nucleases and proteases causes changes seen in apoptotic cells and

eventual cell death.

E) All of the above.

Learning Log Question:

Discuss the role of cytoplasmic determinants and the process of induction in respect to gene expression for normal development.

Chromatin changes

Transcription

RNA processing

mRNAdegradation

Translation

Protein processingand degradation

Degradation of mRNAOR

Target mRNAmiRNA

Proteincomplex

Dicer

The micro-RNA (miRNA)precursor foldsback on itself,held togetherby hydrogenbonds.

1

An enzymecalled Dicer movesalong the double-stranded RNA, cutting it intoshorter segments.

2

One strand ofeach short double-stranded RNA isdegraded; the otherstrand (miRNA) thenassociates with acomplex of proteins.

3

The boundmiRNA can base-pairwith any targetmRNA that containsthe complementarysequence.

4

The miRNA-proteincomplex prevents geneexpression either bydegrading the targetmRNA or by blockingits translation.

5

LO 2.34: The student is able to describe the role of programmed cell death in development and differentiation, the reuse of molecules, and the maintenance of dynamic homeostasis.

SP 7.1: The student can connect phenomena and models across spatial and temporal scales.Explanation:

M.C. Question:Which of the following statement about the apoptotic process it the development of paws in the mouse is TRUE?a. Bcl7 regulates the activation of procaspases which only activate cell death.b. Protein Bax activates procaspases directly, by inducing the release of cytochrome c from mitochondria into the cytosol signaling the beginning of cell death.c. Cytochrome C is released from lysosome into cytosol to kill the cell and thus eliminates

interdigital webs.d. During apoptosis, the cell shrinks and breaks up into membrane-enclosed fragments called apoptotic bodies with subsequent elimination by a process similar to phagocystosise. All of the above

Learning Log/FRQ-style QuestionDiscuss how the immune system responds to an initial pathogenic exposure, and how this initial exposure can lead to a quicker response following a second exposure to the same pathogen. Draw and label the processes that occur.

Programmed cell death, or Apoptosis is of Greek origin, having the meaning "falling off or dropping off", in analogy to leaves falling off trees. This analogy emphasizes that the death of living matter is an integral and necessary part of the life cycle of organisms. Various biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation without damage to neighboring cells. The apoptotic mode of cell death is an active process which plays an important role in the development of multi-cellular organisms and in the regulation , maintenance of the cell populations in tissues . Apoptotic processes are of widespread biological significance, being involved in development, differentiation, proliferation/homoeostasis, regulation and function of the immune system and in the removal of defective and harmful cells. Thus, dysfunction of the apoptotic program is implicated in a variety of pathological conditions. Dynamic homeostasis implies that a system is in a constant state of motion, but in opposite directions. For example, a body's water amount is controlled through intake versus the opposite function of sweat and urination. Therefore, homeostasis is achieved while also remaining in motion, or dynamic. Ultimately, the system's equilibrium doesn't change in spite of dynamic motion.

L.O. 2.35: The student is able to design a plan for collecting data to support the scientific claim that the timing and coordination of physiological events involve regulation.

S.P. 4.2: The student can design a plan for collecting data to answer a particular scientific question.

Explanation: The timing and coordination of many physiological events across all species of organisms involve regulation. In plants, phototropism is an essential process that involves the differential regulation of cell growth within the stem of a plant responding to light, as the cells on the shaded side of the plant elongate more-so than the cells on the lighted side, which allows the plant stem to bend toward light. An experiment completed by Fritz Went supported the hypothesis that differential distribution of the plant hormone auxin is the driver of this physiological response. In animals, 24-hour circadian rhythms , hibernation, estivation, and migration are examples of regulated and specifically-timed physiological events. In bacteria, quorum sensing alters expression of genes when bacteria experience a high population density. As a bacterial population increases, a signaling molecule called an inducer is produced and received by adjacent bacterial cells, which in turn stimulates production of more inducer via positive feedback. After significant amounts of inducer are produced, transcription of certain genes is turned on, producing a response. An example of a response that is stimulated in this way includes bioluminescence of bacteria within certain species of deep-sea squid.

M.C. Question: Quorum sensing would most likely occur when:A) A bacterium senses the production of cAMPB) Tobacco plants are exposed to sunlightC) Bacteria reach a certain critical concentrationD) Predator insects eat herbivorous insectsE) Insulin binds to target cells

FRQ: Describe the difference between long-day and short-dayplants. How can a long-day plant be induced to bloom in the middle of winter?

LO 2.36: The student is able to justify scientific claims with evidence to show how timing and coordination of physiological events involve regulation.SP 6.1: The student can justify claims with evidence.

Explanation: In plants, physiological events deals with interactions between stimuli in the environment as well as molecular signals that are internal. One example of this is phototropism which is the plant’s response to light. Another example is through photoperidodism which is the response to change in the length of night. Internal and external signals in both animals and fungi, protists and bacteria synchronize with environmental cycles and cues. These are seen through hibernation, estivation and migration which are examples of seasonal responses dealing with regulation. In fungi, there is a formation of a fruiting body.

M. C. Question: Which of the following is not an example of physiological events involved in regulation in animals?

A) Release and reaction to pheromonesB) Visual displays in the reproductive cycleC) Sensory cues in the nervous systemD) Circadian rhythms in eukaryotesE) Jet lag in humans

Learning Log/FRQ-style Question:

http://en.wikipedia.org/wiki/Circadian_rhythm

What are examples of physiological events involved with regulation in plants, animals and fungi? Be sure to include one example for each category with elaboration on the process.

Explanation: Photosynthesis is the main mechanism autotrophic organisms like plants ,use to convert light energy into chemical energy. This photosynthetic process happens in the chloroplasts, absorbing carbon dioxide (CO2) from the environment and converting it into oxygen due to the millions of stomata covering the plants surface area. Phototropism is a physiological event that happens when a plant grows toward a positive stimulus like sunlight. During the day the plants photoperiodicity response allowing the organism to respond to the duration of night and day. With this response the plant can raise its leaves during the morning to insure maximum photosynthesis and lower them during the evening. Due to the nitrogen fixing bacteria the nitrogenous materials and minerals are converted from N2 to ammonia. This bacteria provides species with a built-in source of fixed nitrogen for assimilation into organic compounds. These are all mechanism and physical characteristics that a plant need to survive. Heterotrophic animals like bears for instance express these same adaptive qualities when the temperature drops and food becomes scares, this process is called hibernation. Hibernation is the low physiological state when activity is low and metabolism decreases. In sum according to the time of day or season, organisms coordinate various physical adaptations and changes.

Multiple Choice Question: On the shaded side of a boulder there is a large vine, and on the other there is sunlight. Which is NOT a result of increase ethylene?

a) Increase in stem curvature

b) A thicker plant stem

c) Increased auxin growth

d) Increase environmental stress

Free Response Question: A gardener adds a fertilizer that suppose to increase the size of his sunflowers. Unfortunately the gardener planted the flower in a shaded area inches away from the sunlight. Describe affects of the plant hormones and will the plant grow toward the light? Explain why or why not.

LO 2.37: The student is able to connect concepts that describe mechanisms that regulate the timing and coordination of physiological events.SP 7.2: The student can connect concepts in cross domains to generalize or extrapolate in and or across enduring understandings or big ideas.

LO 2.38: The student is able to analyze data to support the claim that responses to information and communication of information affect natural selection.

SP 5.1:The student can analyze data to identify patterns or relationships Explanation: In plants, physiological events involve interactions between environmental stimuli and internal molecular signals. Phototropism, the response to the presence of light, and photoperidism, the response to change in length of light results in flowering in long-day and short-day plants, are both physiological events found in plants. Animals also respond to environmental stimuli. Some examples would be: circadian rhythms, seasonal responses (hibernation and migration), release and reaction to pheromones.

M.C. Question: The prayer plant folds up its leaves each night in accordance with a circadian rhythm. If the plant is shipped halfway around the world to a location where it is daytime there when it is night here, the plant will

A) slowly adjust to synchronize w/the new day-night cycle. B) immediately switch to a new cycle & begin to open leaves in day and close them at night. C) detect the change but remain on its original cycle, therefore still fold leaves in day and open them at night. D) not detect the change, therefore remain on its original cycle.

Learning Log/FRQ-style Question: Behaviors of organisms may be influenced by environmental factors. For each of the following behaviors explain: i. how the environment affects the behavior, and ii) why this behavior increases the survivorship of individuals of a species.

A) Taxis/Kinesis B) Migration

L.O. 2.39 - The student is able to justify scientific claims, using evidence, to describe how timing and coordination of behavioral events in organisms are regulated by several mechanisms.S.P. 6.1 - The student can justify claims with evidence.

Explanation: The varied behaviors of organisms are often regulated by external environmental factors, inner homeostasis functions, and occasionally circadian rhythms that are not as dependent on these factors but on a biological clock in each organism. In animals, behaviors are sometimes innate and sometimes “learned” through interaction with the environment. For example, Tinbergen’s study of the male Stickleback fish found that it displayed agonistic behavior when it encountered the color red – this occurred because the male stickleback was acting on a fixed action pattern – an instinctive behavior that cannot be interrupted. These innate behaviors are regulated by the innate relasing mechanism - a specific neural network. Natural selection favored the evolution of this behavior in Stickleback males because of the competition between them for mates and living space. Therefore, whenever an encounter between two red males occurs, the fixed-action pattern sets in, governing the agonistic behavior displayed by the Stickleback. Sometimes, a lack of resources or other environmental influence will govern an organism’s behavior. For example, siblicide is a prevalent behavior in Nazca Booby populations on a desert island of the Galapagos. Two eggs are often laid for insurance purposes, but if both hatch, the elder bird will push the younger one out of its nest to its certain death. Scientists postulate that this behavior evolved as a direct response to the lack of food resources in this area.

M.C. Question: What would be an example of a behavioral inhibition to the mating process of a bowerbird?A) The sperm fails to fertilize the egg.B) Two birds live on opposite sides of a mountain range.C) A male bird builds an insufficient nest and is rejected.D) Two birds have different mating seasons.

Learning Log/FRQ-Style Question: (a) Deep sea angler fish are known and named for their lure, a mobile, protruding rod of flesh atop their head which lures prey. Bioluminescent bacteria dwell in the tip of the lure, benefitting from nutrients while the angler fish benefits from the bioluminescence of the bacteria. Explain why this relationship is either commensalistic, mutualistic, or parasitic, and contrast it with examples of the other two symbiotic relationships.(b) Also, angler fish demonstrate an extreme sexual dimorphism – the females dwarf the males, which latch onto the females in multitudes during reproduction, releasing sperm directly into the bloodstream. Explain why this is polygyny, polyandry, or monogamy and contrast it with two other examples of the other reproductive behaviors.

LO 2.40 The student is able to connect concepts in and across domain(s) to predict how environmental factors affect responses to in formation and

change behaviorExplanation: This learning objective encompasses how an organism interacts with its environment and being able to understand that timing and behavior contribute to natural selection. Also being able to determine what responses do organisms have to their environment that hurt and also help their survival

chances.• SP 7.2 : The student can connect concepts across domains to generalize or

extrapolate in and/or across understanding and or big ideas

• Connection : The student should be able to give a general list of interactions and behaviors between the environment ,but also be able to cite specific examples that apply to more than just animals.

• Slide 1 of 3

LO 2.40 Multiple choiceObservational learning and insight provide a mechanism to learn new behaviors in response to unexpected events without reinforcement this reduces the time required for behaviors to be acquired. Which is an example of this? A.) European robins learning to open milk bottles, robbing cream from the top of milk bottles and adapting to the use of aluminum foil seals on the bottles, learning to tear them to access the cream B.) Costal garter snakes feeding on banana slugs for survival in California.

C.) A wild goose's flight response to humans decreases after it turns up from a remote winter feeding ground to spend the summer on a lake in a popular park. Compared to its behavior when it first flew in, it soon tolerates people approaching it and eventually almost ignores them. It habituates to the stimuli.

Slide 2 of 3

LO 2.40 Free response

• Explain phototropism and the relationship between the environment and organism. Identify and cite examples of Hibernation, Estivation, and Migration. Also explain the interaction between the organism and the environment.

• Slide 3 of 3