The Science of BiologyChapter 1

2

What are the Properties of Life?

Living organisms:Cellular organization- composed of cellsOrdered complexity- complex and orderedSensitivity- respond to their environmentGrowth, development and reproduction- can grow and

reproduceEnergy utilization-obtain and use energyHomeostasis-maintain internal balanceEvolutionary adaptation-allow for evolutionary

adaptation

3

What are the Cellular Levels of Organization?

Cellular Organization cells

organellesmolecules

atoms

The cell is the basic unit of life.

4

What are the Organism Levels of Organization?

Organismal Level

organism

organ systems

organs

tissues

5

What are the Population Levels of Organization?

Population Level

ecosystem

community

species

population

6

What are Emergent Properties?

Each level of organization builds on the level below it but often demonstrates new features.

Emergent properties: new properties present at one level that are not seen in the previous level

For example: The information present in tissues is not present in a cell but was built on the latter.

7

The Nature of Science

• Deductive reasoning • Inductive reasoning

General principles

Specific predictions of results

Specific observations

General Scientific Principles

Science aims to understand the natural world through observation and reasoning.

8

How hypothesis driven science makes and tests predictions?

A systematic approach is used by scientists to gain understanding of the natural world.

-Observation-Hypothesis formation-Prediction-Experimentation-Conclusion

9

How hypothesis driven science makes and tests predictions?

A hypothesis is a possible explanation for an observation.

A hypothesis

-must be tested to determine its validity

-is often tested in many different ways

-allows for predictions to be made

10

How hypothesis driven science makes and tests predictions?

The experiment-tests the hypothesis-must be carefully designed to test only one variable/factor at a time-consists of a test experiment and a control experiment

If the hypothesis is valid, the scientist can predict the results and do further experiments to confirm its validity.

11

Other approaches of Science to explain living systems

Reductionism (Philosophical approach) - to break a complex process down to its simpler parts

- Metabolism of cells were unraveled by understanding individual pathways and their specific enzymes.

Models – Provide a way to organize thinking about a problem that is difficult to study directly

- Shows a larger picture and how they fit together/interconnect network

- Suggests experiments that can refine or test the model

12

What is Scientific Theory?

A Scientific Theory

-is a body of interconnected concepts

-is supported by scientific reasoning and experimental evidence

-explains facts in some area of study

Research done by scientists is either basic or applied.

13

An example of scientific enquiry by Charles Darwin: His evidence

Similarity of related species

- Darwin noticed variations in related species living in different locations

14

An example of scientific enquiry by Charles Darwin

Evolution: modification of a species over generations-“descent with modification”

Natural selection: individuals with superior physical or behavioral characteristics are more likely to survive and reproduce than those without such characteristics

15

Malthus theory of population growth versus resources availability

• Population growth vs. availability of resources

- population growth

is geometric

- increase in food

supply is arithmetic

16

How Darwin’s Evidence enlightened from Malthus theory?

Population growth vs. availability of resources

- Darwin realized that not all members of a

population survive and reproduce.

-Darwin based these ideas on the writings of Thomas Malthus.

17

Post-Darwin Evolution Evidence

Fossil record

- New fossils are found all the time

- Earth is older than previously believed

Mechanisms of heredity

- Early criticism of Darwin’s ideas were resolved by Mendel’s theories for genetic inheritance.

18

Post-Darwin Evolution Evidence

Comparative anatomy- Homologous structures have

same evolutionary origin, but different structure and function.

- Example: Forelimbs of different vertebrates responding to their evolutionary demands

- Analogous structures have similar structure and function, but different evolutionary origin

- Example: Wings of birds and butterflies

19

Post-Darwin Evolution Evidence

Molecular Evidence

Increased understanding of DNA (genome) and protein (amino acid) structures has led to the development of more accurate phylogenetic trees.

20

Unifying Themes in Biology

Cell theory- All living organisms are made of cells, and all living cells come from preexisting cells.

Cells process information stored in DNA as well as information received from the environment

Molecular basis of inheritance- DNA encodes genes which control living

organisms and are passed from one generation to the next.

21

Unifying Themes in Biology

Structure and Function

-The proper function of a molecule is dependent on its structure.

-The structure of a molecule can often tell us about its function.

22

Unifying Themes in Biology

Evolutionary change

- Living organisms have evolved from the same origin event. The diversity of life is the result of evolutionary change.

Evolutionary conservation

- Critical characteristics of early organisms are preserved and passed on to future generations.

23

Unifying Themes in Biology

Emergent properties

- New properties are present at one level of organization that are not seen in the previous level

24

This project is funded by a grant awarded under the President’s Community Based Job Training Grant as implemented by the U.S. Department of Labor’s Employment and Training Administration (CB-15-162-06-60). NCC is an equal

opportunity employer and does not discriminate on the following basis: against any individual in the United States, on the basis of race, color, religion, sex, national origin, age disability, political affiliation or belief; and against any

beneficiary of programs financially assisted under Title I of the Workforce Investment Act of 1998 (WIA), on the basis of the beneficiary’s citizenship/status as a lawfully admitted immigrant authorized to work in the United States, or his or

her participation in any WIA Title I-financially assisted program or activity.

“This workforce solution was funded by a grant awarded under the President’s Community-Based Job Training Grants as implemented by the U.S. Department of Labor’s Employment and Training Administration.  The solution was created by the grantee and does not necessarily reflect

the official position of the U.S. Department of Labor.  The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the

information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.  This solution is copyrighted by the institution that created it.  Internal use by an organization and/or personal use by an individual for non-commercial purposes is permissible.  All

other uses require the prior authorization of the copyright owner.”