Paul Jungs AP Biology

AP Biology Final FRQ 1. Evolution (Diversity of organisms/Phylogeny/Classification)1) Darwinism (2004A2) a. The nonconsistancy of species - individual variation (phenotypic or genotypic variation) within a species/population Ex) dogs, horses, finches b. Branching evolution, which implies the common descent of all species - common ancestor divergent evolution (one species becomes 2 or more) Ex) vestigial structure (tailbone) from common ancester c. Occurrence of gradual changes in species - small changes over time/ slow rate of change - Gene mutate selection occurs population evolve - accumulation of genotypic/phenotypic changes Ex) Fossil sequence of horse, coat color change, giraffes necks, d. Natural selection as the mechanism for evolution - differential reproductive success - survivors pass genes to next generation Ex) antibiotic (superbacteria) or pesticide resistance (insects), finches, moths

2) Hardy-Weinberg Equilibrium: - allele (gene) frequency remains constant over time - Under certain conditions no evolution occurs - Five conditions 1) Very large population size no genetic drift 2) No movement in or out of a population 3) No net mutation 4) Radom mating no sexual selection 5) No natural selection

3) Adaptation of prokaryotes: 1) fast reproduction out-compete other organisms2) asexual reproduction no need to risk change3) genetic transfer (conjugation, transduction, transformation) can increase species variation4) plasmid provide new phenotype5) diverse metabolism (N2 fixation, anaerobes, chemoautotrophs, variety of substrates)6) extremophiles can colonize habitats inhospitable to others7) endospores resist harsh conditions8) cell walls protection from osmotic lysis or protect from some chemicals9) small high surface area per volume ratio, large number in small space10) restriction enzymes protect from viruses

Prokrayotes altered environments on Earth 1) provide oxygen cyanobacteira through photosynthesis 2) production of unusual organics conversion of CO2 to sugars via Calvin cycle 3) nitrogen fixation nitrogen cycle 4) origin of organelles endosymbiont theory )mitochondria and chloroplastsEcological impact of prokaryotes today 1) chemical cycling (decomposition) N, C, O 2) pathogenesis Super bacteria Biotechnology (genetic engineering) bacteria eating oils to reduce polluted area4) Mutation a) point mutation b) frameshift mutation c) insertion d) deletion

5) Evolution of Angiosperm a) double fertilization pollen tube (no need of water for fertilization) b) cross-fertilization genetic diversity c) fruits and seeds food enhances dispersal by animals, seed dormancy enhances survival, seed coat protect embryo d) broad leaves improved gas exchange, transpiration, stomata, increased light energy harvest, great surface for energy capture, enhanced photosynthetic activity

6) Evolutionary significance of organizing genes into chromosomes 1) genetic variation (crossing over) 2) genetic stability ( maintaining integrity of chromosomes) 3) gene regulation (histon acetylation, methylation) 4) complexity (transposons, alternative splicing) 5) diploid/polyploidy (genetic fitness, backup copy, heterozygocity) 7) Diversity of Organisms* Reptile a) Amniotic Egg - not necessary to return to water for reproduction - protection for embryo - prevent desiccation of embryo (shell) - more efficient reproduction: internal fertilization fewer gametes required - food supply stored in yolk - new hatchlings more fully developed b) Water proof Skin - prevent drying out on land - mechanical /chemical protection of body - permits adaptations to land habitats c) Well-developed Lungs - better able to exchange gas with atmosphere - adaptation to terrestrial habitats; gas exchange with air instead of water - internal, folded up inside body-moist gas exchange surface does not dry out, also protect from damage- no point for holding breath or breeding underwater

8) Phylogeny a) DNA sequence comparison b) amino acid sequence comparison c) structure similarity d) behavioral similarity

** Terms**

Punctuated equilibrium In the fossil record, long periods of apparent stasis, in which a species undergoes little or no morphological change, interrupted by relatively brief periods of sudden change.

Cyanobacteria also known as blue-green algae, blue-green bacteria, and Cyanophyta) is a phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" comes from the color of the bacteria (Greek: (kyans) = blue). The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms. According to endosymbiotic theory, chloroplasts in plants and eukaryotic algae have evolved from cyanobacterial ancestors via endosymbiosis.

Allopatric speciation The formation of new species in populations that are geographically isolated from one another.

Sympatric speciation The formation of new species in populations that live in the same geographic area Duplication of chromosome/polyploidy. Polyploidy A chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division.

Bottleneck effect Genetic drift that occurs when the size of a population is reduced, as by a natural disaster or human actions. Typically, the surviving population is no longer genetically representative of the original population.

Founder effect Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population.

2. Ecology

1) Ecological Succession * Primary succession A type of ecological succession that occurs in an area where there were originally no organisms present and where soil has not yet formed. In primary succession pioneer species like lichen, algae and fungus as well as other abiotic factors like wind and water start to "normalize" the habitat. This creating conditions nearer optimum for vascular plant growth; pedogenesis or the formation of soil is the most important process. These pioneer plants are then dominated and often replaced by plants better adapted to less odd conditions, these plants include vascular plants like grasses and some shrubs that are able to live in thin soils that are often mineral based. For example, spores of lichen or fungus, being the pioneer species, are spread onto a land of rocks. Then, the rocks are broken down into smaller pieces and organic matter gradually accumulates, favouring the growth of larger plants like grasses, ferns and herbs. These plants further improve the habitat and help the adaptation of larger vascular plants like shrubs, or even medium- or large-sized trees. More animals are then attracted to the place and finally a climax community is reached. A good example of primary succession takes place after a volcano has erupted. The resulting barren land is first colonized by pioneer plants which pave the way for later, less hardy plants, such as hardwood trees, by facilitating pedogenesis, especially through the biotic acceleration of weathering and the addition of organic debris to the surface regolith.

* Secondary succession A type of succession that ocrurs when' an existing community has been cleared by some disturbance that leaves the soil or substrate intact. As opposed to the first, primary succession, secondary succession is a process started by an event[1] (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. Simply put, secondary succession is the succession that occurs after the initial succession has been disrupted and some plants and animals still exist. It is usually faster than primary succession as:1. Soil is already present, so there is no need for pioneer species; 2. Seeds, roots and underground vegetative organs of plants may still survive in the soil. A harvested forest going back from being a cleared forest to its original state, the "climax community" (a term to use cautiously), is an example of secondary succession. Each stage a community goes through on its way to the climax community in succession can be referred to as a " seral community."2) Primary production Gross primary production (GPP) is the rate at which an ecosystem's producers capture and store a given amount of chemical energy as biomass in a given length of time. Some fraction of this fixed energy is used by primary producers for cellular respiration and maintenance of existing tissues (i.e., "growth respiration" and "maintenance respiration").[1] The remaining fixed energy (i.e., mass of photosynthate) is referred to as net primary production (NPP).NPP = GPP - respiration [by plants] Net primary production is the rate at which all the plants in an ecosystem produce net useful chemical energy; it is equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (GPP) and the rate at which they use some of that energy during respiration. Some net primary production goes toward growth and reproduction of primary producers, while some is consumed by herbivores.

3) Chemical cyclesA) Water cycleThe sun, which drives the water cycle, heats water in oceans and seas. Water evaporates as water vapor into the air. Ice and snow can sublimate directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the soil. Rising air currents take the vapor up into the atmosphere where cooler temperatures cause it to condense into clouds. Air currents move water vapor around the globe, cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow or hail, and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Snowpacks can thaw and melt, and the melted water flows over land as snowmelt. Most water falls back into the oceans or onto land as rain, where the water flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans. Runoff and groundwater are stored as freshwater in lakes. Not all runoff flows into rivers, much of it soaks into the ground as infiltration. Some water infiltrates deep into the ground and replenishes aquifers, which store freshwater for long periods of time. Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge. Some groundwater finds openings in the land surface and comes out as freshwater springs. Over time, the water returns to the ocean, where our water cycle started.

B) Carbon cycleOne of the major cycles of chemical elements in the environment. Carbon (as carbon dioxide) is taken up from the atmosphere and incorporated into the tissues of plants in photosynthesis. It may then pass into the bodies of animals as the plants are eaten. During the respiration of plants, animals, and organisms that bring about decomposition, carbon dioxide is returned to the atmosphere. The combustion of fossil fuels (e.g. coal and peat) also releases carbon dioxide into the atmosphere.

C) Nitrogen cycle

The nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems (Figure 9s-1). Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids. The store of nitrogen found in the atmosphere, where it exists as a gas (mainly N2), plays an important role for life. This store is about one million times larger than the total nitrogen contained in living organisms. Other major stores of nitrogen include organic matter in soil and the oceans. Despite its abundance in the atmosphere, nitrogen is often the most limiting nutrient for plant growth. This problem occurs because most plants can only take up nitrogen in two solid forms: ammonium ion (NH4+ ) and the ion nitrate (NO3- ). Most plants obtain the nitrogen they need as inorganic nitrate from the soil solution. Ammonium is used less by plants for uptake because in large concentrations it is extremely toxic. Animals receive the required nitrogen they need for metabolism, growth, and reproduction by the consumption of living or dead organic matter containing molecules composed partially of nitrogen.

D) Phosphorous cyclePhosphorus enters the environment from rocks or deposits laid down on the earth many years ago. The phosphate rock is commercially available form is called apatite. Other deposits may be from fossilized bone or bird droppings called guano. Weathering and erosion of rocks gradually releases phosphorus as phosphate ions which are soluble in water. Land plants need phosphate as a fertilizer or nutrient.Phosphate is incorporated into many molecules essential for life such as ATP, adenosine triphosphate, which is important in the storage and use of energy. It is also in the backbone of DNA and RNA which is involved with coding for genetics.When plant materials and waste products decay through bacterial action, the phosphate is released and returned to the environment for reuse.Much of the phosphate eventually is washed into the water from erosion and leaching. Again water plants and algae utilize the phosphate as a nutrient. Studies have shown that phosphate is the limiting agent in the growth of plants and algae. If not enough is present, the plants are slow growing or stunted. If too much phosphate is present excess growth may occur, particularly in algae.A large percentage of the phosphate in water is precipitated from the water as iron phosphate which is insoluble. If the phosphate is in shallow sediments, it may be readily recycled back into the water for further reuse. In deeper sediments in water, it is available for use only as part of a general uplifting of rock formations for the cycle to repeat itself.

4) SymbiosisA) Mutualism - A symbiotic relationship in which both participants benefit.A well known example of mutualism is the relationship between ungulates (such as cows) and bacteria within their intestines. The ungulates benefit from the cellulase produced by the bacteria, which facilitates digestion; the bacteria benefit from having a stable supply of nutrients in the host environment. Mutualism plays a key part in ecology. For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48% of land plants rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements. In addition, mutualism is thought to have driven the evolution of much of the biological diversity we see, such as flower forms (important for pollination mutualisms) and co-evolution between groups of species.[1] However mutualism has historically received less attention than other interactions such as predation and parasitism.[2][3]B) Commensalism- A symbiotic relationship in which one organism benefits but the other is neither helped nor harmed.An example of commensalism: cattle egrets foraging in fields among cattle or other livestock. As cattle, horses and other livestock graze on the field, they cause movements that stir up various insects. As the insects are stirred up, the cattle egrets following the livestock catch and feed upon them. The egrets benefit from this relationship because the livestock have helped them find their meals, while the livestock are typically unaffected by it.C) Parasitism- A symbiotic relationship in which one organism, the parasite, benefits at the expense of another, the host, by living either within or on the host. Parasites may be characterized as ectoparasitesincluding ticks, fleas, leeches, and licewhich live on the body surface of the host and do not themselves commonly cause disease in the host; or endoparasites, which may be either intercellular (inhabiting spaces in the hosts body) or intracellular (inhabiting cells in the hosts body). Intracellular parasitessuch as bacteria or virusesoften rely on a third organism, known as the carrier, or vector, to transmit them to the host. Malaria, which is caused by a protozoan of the genus Plasmodium transmitted to humans by the bite of an anopheline mosquito, is an example of this type of interaction. The plant disease known as Dutch elm disease (caused by the fungus Ceratocystis ulmi) can be spread by the European elm bark beetle. A form of parasitism called brood parasitism is practiced by the cuckoo and the cowbird, which do not build nests of their own but deposit their eggs in the nests of other species and abandon them there. Though the cowbirds parasitism does not necessarily harm its hosts brood, the cuckoo may remove one or more host eggs to avoid detection, and the young cuckoo may heave the hosts eggs and nestlings from the nest. 5) Population Ecology (1) Population GrowthA population is a group of individuals of the same species living in the same geographic area. The study of factors that affect growth, stability, and decline of populations is population dynamics. All populations undergo three distinct phases of their life cycle: 1. growth 2. stability 3. decline Population growth occurs when available resources exceed the number of individuals able to exploit them. Reproduction is rapid, and death rates are low, producing a net increase in the population size.Population stability is often proceeded by a "crash" since the growing population eventually outstrips its available resources. Stability is usually the longest phase of a population's life cycle.Decline is the decrease in the number of individuals in a population, and eventually leads to population extinction.Factors Influencing Population GrowthNearly all populations will tend to grow exponentially as long as there are resources available. Most populations have the potential to expand at an exponential rate, since reproduction is generally a multiplicative process. Two of the most basic factors that affect the rate of population growth are the birth rate, and the death rate. The intrinsic rate of increase is the birth rate minus the death rate.

Two modes of population growth. The Exponential curve (also known as a J-curve) occurs when there is no limit to population size. The Logistic curve (also known as an S-curve) shows the effect of a limiting factor (in this case the carrying capacity of the environment). Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.Population Growth Potential Is Related to Life HistoryThe age within it's individual life cycle at which an organism reproduces affects the rate of population increase. Life history refers to the age of sexual maturity, age of death, and other events in that individual's lifetime that influence reproductive traits. Some organisms grow fast, reproduce quickly, and have abundant offspring each reproductive cycle. Other organisms grow slowly, reproduce at a late age, and have few offspring per cycle. Most organisms are intermediate to these two extremes.

Age structure refers to the relative proportion of individuals in each age group of a population. Populations with more individuals aged at or before reproductive age have a pyramid-shaped age structure graph, and can expand rapidly as the young mature and breed. Stable populations have relatively the same numbers in each of the age classes.

Comparison of the population age structuire in the United States and Mexico. Note the deographic bulge in the Mexican population. The effects of this buldge will be felt for generations. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

The Baby Boomers and Gen X. As the population bulge, the baby Boomers born after World War II, aged and began to have children of their own this created a secondary bulge termed Generation X. What happens when the Generation X members begin to have their own children? Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.Human populations are in a growth phase. Since evolving about 200,000 years ago, our species has proliferated and spread over the Earth. Beginning in 1650, the slow population increases of our species exponentially increased. New technologies for hunting and farming have enabled this expansion. It took 1800 years to reach a total population of 1 billion, but only 130 years to reach 2 billion, and a mere 45 years to reach 4 billion. Despite technological advances, factors influencing population growth will eventually limit expansion of human population. These will involve limitation of physical and biological resources as world population increased to over six billion in 1999. The 1987 population was estimated at a puny 5 billion. Human population growth over the past 10,000 years. Note the effects of worldwide disease (the Black death) and technological advances on the populatiuon size. Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.Populations Transition Between Growth and StabilityLimits on population growth can include food supply, space, and complex interactions with other physical and biological factors (including other species). After an initial period of exponential growth, a population will encounter a limiting factor that will cause the exponential growth to stop. The population enters a slower growth phase and may eventually stabilize at a fairly constant population size within some range of fluctuation. This model fits the logistic growth model. The carrying capacity is the point where population size levels off.

Relationship between carrying capacity (K) and the population density over time. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.Several Basic Controls Govern Population SizeThe environment is the ultimate cause of population stabilization. Two categories of factors are commonly used: physical environment and biological environment. Three subdivisions of the biological environment are competition, predation, and symbiosis. Physical environment factors include food, shelter, water supply, space availability, and (for plants) soil and light. One of these factors may severely limit population size, even if the others are not as constrained. The Law of the Minimum states that population growth is limited by the resource in the shortest supply. The biological role played by a species in the environment is called a niche. Organisms/populations in competition have a niche overlap of a scarce resource for which they compete. Competitive exclusion occurs between two species when competition is so intense that one species completely eliminates the second species from an area. In nature this is rather rare. While owls and foxes may compete for a common food source, there are alternate sources of food available. Niche overlap is said to be minimal.

**Terms**

Competitive Exclusion Principle:a proposition which states that two species competing for the same resources cannot coexist if other ecological factors are constant. When one species has even the slightest advantage or edge over another, then the one with the advantage will dominate in the long term. One of the two competitors will always overcome the other, leading to either the extinction of this competitor or an evolutionary or behavioral shift towards a different ecological niche. The principle has been paraphrased into the maxim "complete competitors cannot coexist".

R-/K- selection:r-selection (unstable environments)In unstable or unpredictable environments, r-selection predominates as the ability to reproduce quickly is crucial. There is little advantage in adaptations that permit successful competition with other organisms, because the environment is likely to change again. Traits that are thought to be characteristic of r-selection include: high fecundity, small body size, early maturity onset, short generation time, and the ability to disperse offspring widely.Organisms whose life history is subject to r-selection are often referred to as r-strategists or r-selected. Organisms who exhibit r-selected traits can range from bacteria and diatoms, to insects and weeds, to various semelparous cephalopods and mammals, particularly small rodents.K-selection (stable environments)In stable or predictable environments, K-selection predominates as the ability to compete successfully for limited resources is crucial and populations of K-selected organisms typically are very constant and close to the maximum that the environment can bear (unlike r-selected populations, where population sizes can change much more rapidly).Traits that are thought to be characteristic of K-selection include: large body size, long life expectancy, and the production of fewer offspring that require extensive parental care until they mature. Organisms whose life history is subject to K-selection are often referred to as K-strategists or K-selected. Organisms with K-selected traits include large organisms such as elephants, trees, humans and whales, but also smaller, long-lived organisms such as Arctic Terns.[8]

Cryptic coloration: Camouflage that makes a potential prey difficult to spot against its background. Aposematic coloration: The bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators. Mullerian mimicry: A mutual mimicry by two unpalatable species. Bastesian mimicry: A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators. Taxis: An oriented movement toward or away from a stimulus,

Kin selection: Kin selection refers to the evolution of traits because they are passed on by the relatives (the kin) of individuals who express the traits. The main kind of trait that is thought to evolve through kin selection is altruism. The way this is proposed to occur is as follows. Suppose altruism is a genetic trait that some individuals will express but for which other individuals can carry the alleles but not express them. Suppose an altruistic individual helps another individual to reproduce. If that individual (the recipient of the altruist's help) is kin to the altruist, that means it is a genetic relative, likely to carry the same alleles, and therefore likely to carry the allele for altruism. So the allele for altruism can be reproduced by the individual who receives help if that individual is related to the altruist. It may be reproduced so much that it increases in the population, even though the altruist does NOT reproduce it very much. Altruism can evolve, therefore, not because it increases the survival and reproduction of the individual who expresses the trait of altruism (since this individual has decreased reproduction) but because it is reproduced by kin of that individual who have, but do not express, the alleles for altruism. Like other traits, altruism will evolve if it is passed from generation to generation more than are alternative alleles for non-altruism. However, we can't describe how altruism will evolve based on the survival and reproduction of the individuals who express altruism, so our usual measure of relative fitness does NOT work to explain the evolution of altruism. Instead, we need to consider something called "inclusive fitness." Inclusive fitness refers to the degree to which a trait is passed from generation to generation. The trait can be passed from generation to generation directly, by reproduction by individuals who express the trait, and also indirectly, when individuals who express the trait help (are altruistic toward) individuals who carry the alleles for the trait, and who reproduce more because they receive help from the altruistic individuals who express the trait. So both ways in which a trait like altruism can be passed on must be considered to evaluate its inclusive fitness.

3. Homeostasis (Hormonal regulation) A) Regulation of glucose level Blood sugar levels are regulated by negative feedback in order to keep the body in homeostasis. The levels of glucose in the blood are monitored by the cells in the pancreas's Islets of Langerhans. If the blood glucose level falls to dangerous levels (as in very heavy exercise or lack of food for extended periods), the Alpha cells of the pancreas release glucagon, a hormone whose effects on liver cells act to increase blood glucose levels. They convert glycogen into glucose (this process is called glycogenolysis). The glucose is released into the bloodstream, increasing blood sugar levels.When levels of blood sugar rise, whether as a result of glycogen conversion, or from digestion of a meal, a different hormone is released from beta cells found in the Islets of Langerhans in the pancreas. This hormone, insulin, causes the liver to convert more glucose into glycogen (this process is called glycogenesis), and to force about 2/3 of body cells (primarily muscle and fat tissue cells) to take up glucose from the blood through the GLUT4 transporter, thus decreasing blood sugar. When insulin binds to the receptors on the cell surface, vesicles containing the GLUT4 transporters come to the plasma membrane and fuse together by the process of exocytosis and thus enabling a facilitated diffusion of glucose into the cell. As soon as the glucose enters the cell, it is phosphorylated into Glucose-6-Phosphate in order to preserve the concentration gradient so glucose will continue to enter the cell.[1] Insulin also provides signals to several other body systems, and is the chief regulatory metabolic control in humans.There are also several other causes for an increase in blood sugar levels. Among them are the 'stress' hormones such as adrenaline, several of the steroids, infections, trauma, and of course, the ingestion of food.Diabetes mellitus type 1 is caused by insufficient or non-existent production of insulin, while type 2 is primarily due to a decreased response to insulin in the tissues of the body (insulin resistance). Both types of diabetes, if untreated, result in too much glucose remaining in the blood (hyperglycemia) and many of the same complications. Also, too much insulin and/or exercise without enough corresponding food intake in diabetics can result in low blood sugar (hypoglycemia).

B) Regulation of calcium level When blood calcium becomes too low, calcium-sensing receptors in the parathyroid gland become activated. This results in the release of PTH, which acts to increase blood calcium, e.g. by release from bones (increasing the activity of bone-degrading cells called osteoclasts). This hormone also causes calcium to be reabsorbed from urine and the GI tract.Calcitonin, released from the C cells in the thyroid gland, works the opposite way, decreasing calcium levels in the blood by causing more calcium to be fixed in bone.

C) Regulation of Blood volume The body's homeostatic control mechanisms, which maintain a constant internal environment, ensure that a balance between fluid gain and fluid loss is maintained. The hormones ADH (Anti-diuretic Hormone, also known as vasopressin) and Aldosterone play a major role in this. If the body is becoming fluid-deficient, there will be an increase in the secretion of these hormones (ADH), causing fluid to be retained by the kidneys and urine output to be reduced. Conversely, if fluid levels are excessive, secretion of these hormones (aldosterone) is suppressed, resulting in less retention of fluid by the kidneys and a subsequent increase in the volume of urine produced. If there is too much Carbon dioxide(CO2) in the blood, it can cause the blood to become acidic. People respirate heavily not due to low oxygen(O2) content in the blood, but because they have too much CO2.

D) Body Temperature E) OsmoregulationOsmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution the more water wants to move into the solution. Pressure must be exerted on the hypertonic side of a selectively-permeable membrane to prevent diffusion of water by osmosis from the side containing pure water.Organisms in both aquatic and terrestrial environments must maintain the right concentration of solutes and amount of water in their body fluids; this involves excretion (getting rid of metabolic wastes and other substances such as hormones that would be toxic if allowed to accumulate in the blood) via organs such as the skin and the kidneys; keeping the amount of water and dissolved solutes in balance is referred to as osmoregulation.Waste products of nitrogen metabolismAmmonia is a toxic by-product of protein metabolism and is generally converted to less toxic substances after it is produced then excreted; mammals convert ammonia to urea, whereas birds and reptiles form uric acid to be excreted with other wastes via their cloacas.Achieving osmoregulation in vertebratesFour processes occur: filtration - fluid portion of blood (plasma) is filtered from a nephron (functional unit of vertebrate kidney) structure known as the glomerulus into Bowman's capsule or glomerular capsule (in the kidney's cortex) and flows down the proximal convoluted tubule to a "u-turn" called the Loop of Henle (loop of the nephron) in the medulla portion of the kidney. reabsorption - most of the viscous glomerular filtrate is returned to blood vessels that surround the convoluted tubules. secretion - the remaining fluid becomes urine, which travels down collecting ducts to the medullary region of the kidney. excretion - the urine (in mammals) is stored in the urinary bladder and exits via the urethra; in other vertebrates, the urine mixes with other wastes in the cloaca before leaving the body; ( frogs also have a urinary bladder).

F) Stress response (acute and slow response)G) Sympathetic/Parasympathetic (flight or fight response)H) Acid-base regulation Acid-base homeostasis is the part of human homeostasis concerning the proper balance between acids and bases, in other words, the pH. The body is very sensitive to its pH level, so strong mechanisms exist to maintain it. Outside the acceptable range of pH, proteins are denatured and digested, enzymes lose their ability to function, and death may occur.The kidneys maintain acid-base homeostasis by regulating the pH of the blood plasma. Gains and losses of acid and base must be balanced. The study of the acid-base reactions in the body is acid base physiology.

4. Genetics (term ) * Epistasis- A type of gene interaction in which one gene alter.; the phenotypic effects of another gene that is Independently inherited.

* Pleiotropy * Polygenic * Codominance * sickle-cell anemia

* Cystic fibrosisCystic fibrosis (also known as CF or mucoviscidosis) is a common recessive genetic disease which affects the entire body, causing progressive disability and often early death. The name cystic fibrosis refers to the characteristic scarring (fibrosis) and cyst formation within the pancreas, first recognized in the 1930s.[1] Difficulty breathing is the most serious symptom and results from frequent lung infections that are treated with, though not cured by, antibiotics and other medications. A multitude of other symptoms, including sinus infections, poor growth, diarrhea, and infertility result from the effects of CF on other parts of the body.CF is caused by a mutation in the gene for the protein cystic fibrosis transmembrane conductance regulator (CFTR). This gene is required to regulate the components of sweat, digestive juices, and mucus. Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis. CF develops when neither gene works normally. Therefore, CF is considered an autosomal recessive disease.CF is most common among Caucasians; one in 25 people of European descent carry one allele for CF.The hallmark symptoms of cystic fibrosis are salty tasting skin,[7] poor growth and poor weight gain despite a normal food intake,[8] accumulation of thick, sticky mucus,[9] frequent chest infections and coughing or shortness of breath.[10

* Tay-Sachs disease TaySachs disease (abbreviated TSD, also known as GM2 gangliosidosis or Hexosaminidase A deficiency) is an autosomal recessive genetic disorder. In its most common variant, known as infantile TaySachs disease, it causes a relentless deterioration of mental and physical abilities that commences around six months of age and usually results in death by the age of four.[1]It is caused by a genetic defect in a single gene with one defective copy of that gene inherited from each parent. The disease occurs when harmful quantities of gangliosides accumulate in the nerve cells of the brain, eventually leading to the premature death of those cells. There is currently no cure or treatment. TaySachs disease is rare, and other autosomal recessive disorders such as cystic fibrosis and sickle cell anemia, are far more common.The disease is named after British ophthalmologist Warren Tay, who first described the red spot on the retina of the eye in 1881, and the American neurologist Bernard Sachs of Mount Sinai Hospital, New York who described the cellular changes of Tay-Sachs and noted an increased prevalence in the Eastern European Jewish (Ashkenazi) population in 1887.