Chapter 1: What is Biology?

What is Biology?

»Bio-: means life

• – ology: Study of

• Biology is the study of life/living things

Branches of Biology

• Zoology: study of animals

• Botany: study of plants

• Paleontology: study of ancient life

Why Study Biology?• Live longer, healthier lives

• Use evidence to learn about the natural world

• Pleasure of learning

• Understanding the “web of life” (all organisms are connected to each other)

• Understand/control our future– Why things happen and what could happen in

the future

Themes in Biology

• Flow of energy through systems

– Cell Organism Biosphere

– Powers all life processes

• Interaction of systems

– Interacting with the environment

• Unity within diversity

Themes in Biology• Homeostasis: regulation

of an organism’s internal environment to maintain survival

• Evolution: gradual change in a species through adaptations over time

• Biology is always expanding and changing the field of study

Characteristics of All Living Things

1. Made up of cells

– Unicellular (made of one cell) vs. multicellular (made up of many cells)

2. Highly organized

3. Use energy– Ex: metabolism

Building chemical substances

Energy required Energy released

Breaking down chemical substances

4. Growth and Development

• Growth: increase in the amount of material (size) and the formation of new structures

• Development: all of the changes that take place during an organism’s lifespan

5. Have a life span

6. Reproduction: sexual vs. asexual– Needed for the survival of a species– Most multicellular species reproduce

sexually

7. Respond to a stimulus (ex: blink/flinch when something is thrown at you)

8. Adaptations: evolution– Variation of traits that are inherited

9. Maintain homeostasis: internal balance

Matter Organization

atoms

elements

molecules

• 6 most abundant elements in all living things

– Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur, and Phosphorus

• Organelles and cells

– Organelles are mini “organs” found in every cell

cells

tissues

organs

organ systems

Organisms

unicellular, multicellular, or colonial

Few

Many

Species

Populations

Communities

Ecosystems

Biomes

Biosphere

Bell Ringer:

1. List the 9 characteristics that classify a mushroom as a living thing.

2. What is the name for a collection of living matter enclosed by a barrier that separates is from its surroundings?

a. cell b. cell culture c. cell fractionation d. DNA

3. What is the name for a combination of chemical changes that builds up or breaks down material in an organism?

a. homeostasis b. metabolism

c. sexual reproduction d. cell culture

The Scientific Method:

• http://dsc.discovery.com/tv-shows/mythbusters/videos/surreal-gourmet-hour.htm

Scientific Method• common steps used to gather information

and answer questions (8 steps)1. make observations: use your senses2. state the problem3. gather information 4. make a hypothesis: an explanation for a

question or a problem that can be tested– has to be able to be tested can be

disproved– is not a guess or a fact (sometimes

cannot be 100% proven accurate)

5. test the hypothesis through an experiment: procedure that tests a hypothesis by collecting information under controlled conditions

6. collect and gather data: information obtained from the experiment

7. draw a conclusion: was the hypothesis correct or incorrect?

8. publish results in scientific journals– allows other scientists to repeat

experiment– Ex: Redi’s and Pasteur’s experiments

(disproved spontaneous generation)

Theory• Well-supported hypothesis

• Well-tested explanation

• Can be revised or replaced by another theory

Controlled Experiments• involve two groups: control group

and experimental group

• control: standard by which all conditions are kept the same

• experimental group: the test group in which all conditions are kept the same except for the single condition being tested

–only one condition is changed at a time

–independent variable: what is being changed (manipulated variable)

• affects the outcome of the experiment

• dependent variable: results from the change of the independent variable (responding variable)

–changes to it depend on changes made to the independent variable

• Not all experiments are controlled (ex: field studies)

Qualitative Data• Using the senses to describe

observations and gather information

• What you see, smell, taste, touch…etc.

• Describe using words

Quantitative Data• Experiments yield

numerical data• System of measurement

(SI): metric system– Base units:

• length meters (m)• mass grams (g)• volume liters (L)• time seconds (s)• temp °C

– Based on multiples of 10

• Prefixes: – kilo (1000)– hecto (100)– deca (10)– deci (0.1 or 1/10)– centi (0.01 or 1/100)– milli (0.001 or 1/1000)

Science and Society• Knowledge gained through research is

never good or bad• Attempts to explain how and why things

happen• Science is objective: can be tested and

measured• Society is dealing with the subjective

–Social, moral, and ethical concerns (right vs. wrong)

• Pure science

–Gaining knowledge through discovery

• Applied science

–Technology that applies knowledge to fit society’s needs and problems

–Involves making improvements in human life

• Inductive reasoning–Reasoning about something from a

set of facts–Start with a specific statement or

fact make a general statement• Deductive reasoning

–Suggesting something from a set of facts or general rules

–Start with a general rule or fact make a specific statement from that general rule

Microscopes

• Light vs. electron

• Electron: SEM vs. TEM

Lab Techniques• Cell cultures-make copies

• Cell fractionation

–Separate into parts

Bell Ringer:1. Place the following steps of an experimental

investigation in the correct order:__ Form a hypothesis __ Ask a question

__ Record and analyze results __ Draw a conclusion

__ Set up a controlled experiment

2. What type of microscope allows light to pass through the specimen and uses two lenses to form an image?a. TEM b. electron c. compound light d. SEM

3. The type of microscope that focuses beams of electrons on specimens is the

22a. compound b. electron c. scanning d. compound light