the study of the living world

Bios — life

-logia —

study of

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From the Greek

Studying biology reveals His power and majesty because we see the Creator in His creations.

What are these unifying themes for our study of biology?

All biological sciences are tied together by

“unifying themes” that overlap and interlock with

one another.

1. The Cell theory and the organization of living systems.

2. The molecular basis of inheritance3. The relationship between structure and function.4. Matter and Energy flow in living systems.5. Diversity through Natural Selection and Evolution

◦ The Cell Theory and organization

“How does the Cell Theory help us understand growth and reproduction of all living organisms?”

All organisms are composed of cells

The cell is the basic unit of life.

All cells come from pre-existing cells.

◦ The Molecular basis of Inheritance

“What are the mechanisms of genetic inheritance and the environmental and genetic causes of gene mutations and expression?”

◦ The molecular basis of Inheritance

“What is the role of DNA in the unity of life on Earth and how does that explain the importance of variation within populations for the survival of species?”

◦ Structure and Function

“How do the structures of organisms enable life’s functions?”

leaf stomata/gas exchange

skeleton/upright body position

Dolphin melon/echolocation

◦ Matter and Energy in Organisms and Ecosystems

“How do organisms obtain and use energy they need to live and grow?”

“How do organisms interact with the living and non-living environment to obtain matter and energy?”

◦ Matter and Energy in Organisms and Ecosystems

◦ Diversity through Natural Selection and Evolution

”How can there be so many similarities among organisms yet so many different plants, animals, and microorganisms? What factors cause the process of evolution of species over time?”

While there are millions of different species on the earth with very different adaptations – they all share

one thing in common – they all are ALIVE

But what makes something alive ?

Are there common attributes that all livingthings share?

WHAT ARE THEY?

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Cells, all organisms consist of one or more cells

Complex and highly ordered;

H maintain a stable internal environment (homeostasis),

Respond to stimuli

Evolve adaptations to their environments for survival.

Grow, develop and reproduce,

E obtain and use energy (metabolism)

❖Composed of one or more cells (basic unit of life)

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Cells made of cells

unicellular

multicellular

❖Despite their small size cells are highly complex and organized!

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Complex and highly organized

Living things adjust to their surroundings

They maintain a relatively stable internal environment, even when external conditions change dramatically.

examples:◦ Body temperature◦ Water balance

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Homeostasis(staying the same)

Amoeba sisters

◦ All living organisms expend energy to keep conditions

inside their cells within certain limits. This process is

called homeostasis.

◦ For example, specialized cells help leaves regulate

gases/water that enter and leave the plant.

stomata

Living things respond to stimuli in their environment

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Respond to stimuli

⚫ Examples:

⚫ migration

⚫ phototropism

⚫ sneeze

A stimulus is a signal to which an organism

responds.

Example: migration

Example: chemical protection

25 weirdest animal defensesDolphins and whales

Beak shape for food source Fur color to evade predators

Living things grow and change over their lives:

• Reproduce cells for repair or increase in size.

6 wks29-32 wks16 wks (4 mo)

1 wk

develop

• All or part of an organism can change form during its life time.

For example:

◦ During development, a single fertilized egg divides again and

again.

◦ As these cells divide, they differentiate, which means they

begin to look different from one another and to perform different

functions.

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Create new individuals◦ Asexually

◦ Sexually

Reproduce

Organisms transform energy

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The combination of chemical reactions through

which an organism builds up or breaks down

materials for energy is called

metabolism.

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Cells, all organisms consist of one or more cells

Complex and highly ordered;

H maintain a stable internal environment (homeostasis),

Respond to stimuli

Evolve adaptations to their environments for survival.

Grow, develop and reproduce,

E obtain and use energy (metabolism)

What Is Science?

How do we study Biology?

Characteristics of Life

Read & Study Ch. 1

What’s the evidence for knowing?

Applying the Scientific Method

Science is a detailed process of observation,

trial and error, experimentation, interpretation,

review, and yes even a little bit of luck and

chance.

And unlike a linear

list of instructions,

it is an ongoing,

iterative process.

How do we go about “studying” science- and therefore, Biology?

We need an organized way to generate reliable data, then relate the data concepts, relationships, etc. to support a claim.

Science can only deal with things that can be OBSERVED.

Good Science = Good Observations

https://www.youtube.com/watch?v=IGQmdoK_ZfY

Selective Attention

https://www.youtube.com/watch?v=xNSgmm9FX2s

◼ Use one or more of the 5

senses to gather information

◼ Note and record … actual qualitative and quantitative data/information

◼ In science, observations should never be emotional! (it’s not about how you feel)

◼ Observations can then be used as the basis of a claim (hypothesis).

Which sense provides the fastest reaction time?

Observations

vs Inferences

examples from this room?

◼ Logical interpretation based upon prior knowledge and experience

◼ Based upon observations

Use your observations to make a prediction or explanation

1. There is a representation of a face on one side of the coin.

2. The Latin word "Dei" means "God."

3. The coin was made by deeply religious people.

4. The date 1722 is printed on one side of the coin.

5. The coin was made in 1722.

Inference orObservation?

• Scientists use both observations and inferences when proposing hypotheses

• In laboratory exercises, record observations NOT inferences

An Exercise in Observations

Objectives: 1. Use a model to explain

indirect observations. 2. Develop and test hypotheses. 3. Observe and record

observations. 4. Compare direct and indirect

observations.

Observations lead to questions…

When we ask questions…

We begin the process of Science

The most reliable means to ensure that experiments produce reliable information in response to a specific question.

The steps taken to answer a specific question.

The scientific method involves recognizing the existence of a problem, MAKING A CLAIM about the problem or suggesting a solution.

Then, accumulating data through experimentation that can be used as EVIDENCE.

Finally validating the claim by providing REASONINGthat shows how the evidence supports the claim.

Results and conclusions should be consistent and verifiable by other scientists and investigators.

A general pathway

• Observe world (collect observations/facts)

• Ask “why/how” questions.

• Make explanatory hypothesis (predictions)

• Test these by experiment or further observation

• analyze results.

• draw conclusions –which may require a new hypothesis.

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•Writing a hypothesis

•Identifying controlled & manipulated variables

•Representing and interpreting data

a tentative explanation or prediction for an observation or scientific problem that can be tested by further investigation.

Write the hypothesis so that it is testable:

Question: Does spending more time on Homework increase your chances of getting an ‘A’ in Biology?

If I spend 1 hour each night doing homework then I will get an “A” in biology, because studying each day instead of cramming the night before lets the information stay in long term memory.

The “if…then…because” format for a hypothesis allows you to clearly define the independent and dependent variables that you are designing into the experiment.

Independent Variable (IV)

The independent variable is what is manipulated (selected and/or changed) by the experimenter.

It is selected to see how it affects the outcome of the experiment.

Dependent Variable (DV)

The dependent variable is the response to event being studied and expected to change. It is the response that is measured.

The dependent variable, is most often the data that is collected because it is in response to what was manipulated.

Have you controlled for as many variables as possible and set up a control group?

Have you repeated the experiment at least three times with the same results?

Have others been able to repeat the experiment with similar results?

Does your experimental design keep as many things as possible constant with only one (the independent variable) change so you can be confident the results are due to that change?

Do you have a control group? A group that has nothing done to it so you can compare to the experimental group.

A scientist wants to find out if caffeine intake influences recall of a word list.

Write a testable hypothesis

Independent (manipulated) variable

Dependent (responding) variable

If the subject takes in 100 mg of caffeine, then they will recall more words from a words list because caffeine stimulates the brain to increase short term memory.

A scientist wants to find out which freezes faster cold or hot water?

Try another

Independent (manipulated) variable

Dependent (responding) variable

If cold water is placed in a freezer, then it will freeze faster than the same amount of hot water because the molecules in cold water are already slower so it will take less energy to phase change to solid from liquid..

In summary:

♦ Independent (manipulated) variable (I vary) answer the question "What do I change?“

♦ Dependent (responding) variable answers the question "What am I going to observe or measure?”

♦ Controlled variables answer the question"What do I keep the same?”

♦ The Experimental Control answersthe question “How do my results compare?”

Experimental Question:“Is there a specific factor that determines who wins a thumb war?”

Homework:

Read and Sign Lab Safety contract

Read and Study Ch. 1

Complete: The Martian and the Car handout

Review the power point notes (go to the website) http://mrswhittsweb.pbworks.com