UNIT 1: The Science of Life

1
UNIT 1 The Science of Life

• BIG IDEA Biology is the study of living things
  and their characteristics, using the tools of
  science

2
Part1 How do we know if something is alive?
3

• Characteristics of Life
• Cellular Organization
• Use Energy for Metabolism
• Growth and Development
• Respond to Stimuli
• Homeostasis
• Reproduce
• Heredity

4
Cellular Organization

• A cell is the smallest unit capable of all life
  functions
• Levels of Organization
• Cells ? Tissues ? Organs ? Organ Systems ?Organism

5
A
C
B
6
Use Energy

• Energy is needed to run life sustaining chemical
  reactions, like movement, growth, and repair.
• Metabolism is the sum of all these reactions.

7
Metabolism

• Metabolism manages the energy and material
  resources in a cell.
• There are two basic types.

8
Catabolic

• Break down large molecules
• Releases/ Stores energy
• For example, cellular respiration is the process
  that breaks down sugar molecules into small
  energy storing molecules

9
Anabolic

• Build larger molecules
• Uses energy
• For example, protein synthesis is the building of
  large proteins from smaller molecules called
  amino acids.

10
Growth and Development

• Growth increase of living matter (making more
  cells)
• Development change into mature adult

11
Response to Stimuli

• Stimulus a change in the environment
• Organism respond and react to changes around them
• For example, animals run from predators.
• Think of stimuli you react to.

12
(No Transcript)
13
(No Transcript)
14
Homeostasis

• Homeostasis to maintain the same internal
  environment in response to changes in the
  external environment
• What internal changes does your body regulate?

15
Homeostasis

• Some examples temperature, water and salt
  levels, blood sugar levels

16
Reproduction

• Process by which organisms make more of their own
  kind
• Necessary for the survival of the species
• Asexual and sexual

17
Heredity

• Organisms pass hereditary information in genes to
  their offspring.
• Genes are encoded in the molecule called DNA
• Allows for adaptations and changes through time

18
Tell what characteristics of life each item has.

• Seed
• Volcano
• Chicken egg
• Bread dough
• Moldy bread
• A branch off a tree

19
DO NOW

• Think of a characteristic of life that a
  nonliving object might display and explain what
  it is.

20
Tools Used by Biologists Study Living Things

1. Scientific Method
2. Microscope
3. Metric System

21
Scientific Method
22
Identify the Problem/Purpose

• Often developed from observations made of nature.

23
Hypothesis and Prediction

• A hypothesis is a proposed explanation for the
  stated problem.
• It must be testable!
• Then scientists can make a prediction for the
  outcome of your experiment.
• Predictions can be stated as If. Then
  statement.

24
Design an Experiment

• Use a controlled experiment to test your
  hypothesis.
• Keep all the test conditions the same except for
  the variable you are testing

25
Record Observations/Data/Results

• Collect data in the form of measurements and
  observations about experiment.
• Reported in metric/SI units

26
Two types of Data

• Quantitative
• Data that uses numerical values, measurements
• E.g. mass, temperature

• Qualitative
• Data that uses descriptions.
• E.g. color, odor, texture

27
Analysis

• Explain your observations, data, and results.
• List the main points that you have learned.
• Was your hypothesis correct?

28
Conclusion

• Answer your problem/purpose statement.
• What would be the next question to ask?
• Remember! Your hypothesis is never PROVEN
  true. It is either rejected or not rejected.

29
Share the Information

• Publish your findings in journals.

30
Theory

• Many accepted hypotheses that explain a similar
  topic form a theory.
• May be revised or replaced!

31
Designing a Controlled Experiment

• A controlled experiment compares a control group
  against an experimental group.

32

• A control group provides a normal standard that
  is used to compare with the experiment group.

33

• The experimental group is the same as the control
  group, except for the one variable that is being
  tested.

34

• The independent variable is the factor that is
  being tested, which changes from the control
  group to the experiment group. It is chosen by
  the scientist.

35

• The dependent variable is the result of the
  experiment and is the factor that is observed and
  measured. It depends on what is tested.

36

• Why does a good experiment control for variables?

37
Metric System

• SI units

38
Scientists Report Measurements as

• Mass
• Volume
• Length

gram
liter
meter
39
Prefix Abbreviation Factor of Base Unit
giga G 1,000,000,000
mega M 1,000,000
kilo k 1,000
hecto h 100
deka da 10
--- --- 1
deci d 0.1
centi c 0.01
mili m 0.001
micro µ 0.000001
nano n 0.000000001
Angstrom Å 0.0000000001
pico p 0.000000000001
40
Converting SI units

• To move from a LARGER unit ? SMALLER unit gt
  MULTIPLY
• To move from a SMALLER unit ? LARGER unit gt
  DIVIDE
• Multiply/Divide by POWERS OF 10

41
SI units are in POWERS OF 10,

• to multiply move the decimal to the right.
• to divide, move the decimal to the left.

42
Move the Decimal

• 1.0 kg 1000.0 g 1,000,000.0 mg
• 1 mm 0.1 cm 0.001 m 0.000001 km
• 4.5678 kg 4567.8 g 4567800 mg