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BIOLOGY 111

CHAPTER 1: An Introduction to the Science of Life

An Introduction to the Science of Life:Chapter Learning Outcomes

1.1) Describe the properties of life common to all living things. (Module 1.1)

1.2) Differentiate between the hierarchical levels of biological organization studied by biologists. (Module 1.2)

1.3) Outline the overall process used by scientists to study science, and how it differs from other ways

of observing the world. (Modules 1.3–1.6)

1.5) Recognize the major themes that underlie the study of biology at all levels. (Modules 1.1, 1.2, 1.7)

1.1) All living organisms share certain properties

1.2) Life can be studied at many levels.

1.3) Scientists use well-established methods to investigate the natural world.

1.4) Scientists try to control for variables.

1.7) Several major themes run throughout the study of biology.

An Introduction to the Science of Life:Outline ✓

All living organisms share certain properties:Biology is the scientific study of life

1.1) All living organisms share certain properties

CORE IDEA: Biology is the scientific study of life. All living things display a shared set of

characteristics. Nonliving matter never displays all of these characteristics simultaneously.

A. Biology is the scientific study of life.

B. Properties of life

All living organisms share certain properties:Biology is the scientific study of life

A. Biology is the scientific study of life and things that affect living systems.

1. Biologists recognize life through a series of characteristics shared by all

living things

All living organisms share certain properties:Properties of life


1. Reproduction

a. All organisms autonomously reproduce their own kind.

2. Growth and development

a. Information carried by DNA controls the pattern of growth in all organisms.

3. Energy use

a. Every organism takes in energy, converts it to useful forms, and releases

energy.


4. Order

a. Each living thing has a complex and well-ordered structure.

5. Cells

a. All living organisms consist of cells.

b. Some living organisms consist of a single cell, while others have trillions.

6. Response to the environment

a. Living organisms respond to changes in the environment.

7. Evolution

a. Individuals with traits that help them survive and reproduce pass the genes

for those traits to offspring.


B. Properties of life?

1. Reproduction


3. Energy use

4. Order

5. Cells


7. Evolution



1. Reproduction


3. Energy use

4. Order

5. Cells


7. Evolution

All living organisms share certain properties:A Virus is not Alive

C. A virus is not alive.

1. Viruses do not display all the properties of life.

2. Viruses are not composed of cells.

3. Viruses cannot reproduce on their own.


B. Properties of life?

1. Reproduction


3. Energy use

4. Order

5. Cells


7. Evolution



1. Reproduction


3. Energy use

4. Order

5. Cells


7. Evolution

Life can be studied at many levels:Levels of biological organization

1.2) Life can be studied at many levels.

CORE IDEA: Life can be studied on a hierarchy of levels from the very large to the very small.

Biologists study life at all levels.

A. Levels of biological organization

Large to Small // Complex to Simple



1. Biosphere

a. The biosphere consists of all life on Earth and all the environments

that support life.



2. Ecosystem

a. An ecosystem includes all the living organisms in one particular area

as well as the nonliving components that affect life.



3. Community

a. A community consists of all the interacting populations of organisms

occupying an ecosystem.


4. Population

a. A population is a group of interacting individual organisms of one species.


5. Organism

a. An organism is an individual living being – a member of a population


6. Organ system

a. An organ system is a group of organs that work together to perform a vital

body function.


7. Organ

a. An organ consists of multiple tissues that cooperate to perform a specific

task.


8. Tissue

a. A tissue is an integrated group of similar cells that work together to perform

a specific function.


9. Cell

a. The cell is the fundamental unit of life.

b. Nothing smaller than a cell is capable of having all life’s properties.

Cell


10.Organelle

a. An organelle is a component of the cell that performs a specific function.

Nucleus


11. Molecule

a. A molecule is a group of atoms bonded together.


12.Atom

a. An atom is the fundamental unit of matter.

b. It is the smallest unit of an element capable of displaying the properties of

an element.

c. Atoms are made up of even smaller units called subatomic particles.

Atoms

Scientists use well-established methods to investigate the

natural world:The Process of Science

1.3) Scientists use well-established methods to investigate the natural world.

CORE IDEA: Scientific investigations always start with observations, which may lead to hypotheses,

and experiments provide data on the validity of the hypothesis. Careful observation and

experimentation allow scientists to investigate hypotheses and develop theories.

A. The Process of Science

B. Science in Action

C. Hypotheses and theories



A. The Process of Science

1. Scientific method is a rough “recipe” for discovery.



A. The Scientific Method

1. Observations

2. Question - based on your observations, what do you want to find out?

3. Hypothesis - proposed explanation for question

- Right or wrong… you will learn about the system!

4. Experiment - testing your hypothesis

- Results

5. Conclusion - Must document the outcome of your hypothesis

- revise and repeat with new hypothesis if needed




1. Observations:

▪ You have a flashlight (#1) that does not work

▪ Flashlight #1 appears to be in good condition

▪ The bulb appears to be LED

▪ Simple switch – no “on” or “off” indicator

▪ The flashlight has AA batteries




2. Question - based on your observations

▪ “What is wrong with flashlight #1?”




2. Question - based on your observations

▪ “What is wrong with flashlight #1?”

▪ “Is there something wrong with the power source in light #1?




3. Hypothesis - proposed explanation for question

- Right or wrong… you will learn about the system!

▪ The batteries in flashlight #1 are dead

▪ Other possibilities:

▪ The Bulb in light #1 is broken

▪ The Switch in light #1 is broken

▪ The batteries are not making correct contact with the switch





- Controlled, repeatable tests of your hypothesis

- Ask yourself, “What is it that needs to be tested?”

- Your Hypothesis should lead you to what is being tested or changed

- The item or condition that is changed in an experiment is the Experimental Variable

- There should be only one experimental variable, and it should be directly

addressed by the Hypothesis






- What should be the experimental variable for these tests?

- The Hypothesis focused on the Batteries… So the batteries are the experimental variable

- We will try a different set of batteries for our experiment






- So… how will we know if the new batteries we are trying are any good?

- We need what is called a Positive Control

Scientists try to control for variables:Positive and negative controls

Positive and negative controls

1. Control groups are used to establish baselines for experiments or to

determine if the experimental system is working correctly

2. Positive control—test for which a known response is expected (you need a variable that will

produce the expected response)

A positive control helps demonstrate that the system is working properly






- One set of experiments will need to include a positive control.

- In this case, the positive control would be to try batteries that have been proven to

be working

- We would need a 2nd flashlight (light #2) that is in working condition

- We could then place the good batteries in the non-working light #1





[2 Types of Controls]

2. Positive control—test for which a known response is expected (you need a variable that will

produce the expected response)

A positive control helps demonstrate that the system is working properly

3. Negative control—group for which no change is expected. Generally, a negative control

involves the removal of the independent variable





2. Negative control—group for which no change is expected. Generally, a negative control

involves the removal of the independent variable

In this case, the negative control would be a flashlight with no batteries. We would expect

the device not to light up.

Negative controls help us to properly understand the system.

What if it has a back-up battery or solar power?




5. Conclusion - Must document the outcome of your hypothesis

Might need to revise and repeat with new hypothesis if needed

▪ Was the hypothesis, “The batteries in flashlight #1 are dead”, correct?

▪ Did we learn anything from our experiment?

▪ What are the next steps?


natural world:Hypotheses and Theories

C. Hypotheses and theories

1. Hypothesis—proposed explanation for a scientific question

a. Must be testable

b. Should be based on observations

c. Experimental results should either support or refute the hypothesis.

2. Theory—well substantiated explanation that is backed by evidence

a. A theory is more comprehensive and broader in scope than a hypothesis.

b. Theories have not been shown to be false.

c. Theories generally explain a great many observations

Several major themes run throughout the study of biology:Evolution

1.7) Several major themes run throughout the study of biology.

CORE IDEA: Major themes—evolution, the relationship of structure and function, the flow of

information, transformations of energy and matter, and connections between elements of biological

systems—underlie the study of biology at all levels. Look for these themes throughout the semester!

A. Evolution

B. Structure and function

C. Energy and matter pathways

D. Information flow

E. Interconnections

F. Applying the themes

A. Evolution

1. Evolution is the descent with gradual modification of species, sometimes

creating new species

a. Theory of evolution by natural selection is the core theme that unifies all of

biology.

b. Evolution by Natural selection was first described by Charles Darwin.

Several major themes run throughout the study of biology:Evolution

B. Structure and function

1. Within biological systems, structure (the shape of something) and function

(what it does) often provide insight into each other.

2. This relationship can be seen at every level of biological organization.

i. If proteins change shape, they also change function

Several major themes run throughout the study of biology:Structure and function

C. Energy and matter pathways

1. All activities in a cell require energy and matter to proceed.

2. Living organisms regulate the transformation of energy and matter.

i. Living things transform and exchange both energy and matter

Several major themes run throughout the study of biology:Energy and matter pathways

D. Information flow

1. Information must be received, transmitted, and used.

2. Information flow is apparent at all levels of biological organization

- Often we will be following the flow of genetic information stored in DNA

Several major themes run throughout the study of biology:Information flow

E. Interconnections

1. Different levels of biological organization

2. Many interconnections within and between levels

3. Emergent properties—often revealed as complexity increases

a. “The whole is greater than the sum of its parts.”

Several major themes run throughout the study of biology:Interconnections

biology 111 - modesto junior collegegervind.faculty.mjc.edu/biology_111/111_lectures/topic 1...an...

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