Introduction to Biology

1
Introduction to Biology
2
Biology The Study of Life

• Section 1 The World of Biology
• Section 2 Themes in Biology
• Section 3 The Study of Biology
• (Section 4 Tools and Techniques will be
  covered in separate power point)

HUTCHCROFT
3
Introduction to Biology

• Biology The study of life

• Life arose more than 3.5 billion years ago in
  Archean eon of Precambrian period

• First organisms (living things) were single
  celled (unicellular) Only life on Earth for
  millions of years

• First multicellular organisms arose in the
  Proterozoic eon of Precambrian period between
• 550 million and 2.5 billion years ago!

• Organisms changed over time (evolved)

4
Introduction to Biology

• New organisms arose from older kinds ! Today,
  estimates suggest 10 100 million organisms may
  exist!!!!!!!!! Only 1.5 million of these have
  been named!

• 99 of organisms that EVER existed may already
  be extinct, having never been identified and
  named!!

• 99 of all animal species are smaller than
  bumble bees!

• Organisms inhabit almost EVERY region of the
  Earth today!

5
The World of Biology

• Biology The study of life
• Characteristics of life
• Organization and Cells
• Response to Stimuli
• Homeostasis
• Metabolism
• Growth and Development
• Reproduction
• Change Through Time

6
Organization and Cells

• All living things are composed of one or more
  cells
• Cells are the smallest units that can perform all
  lifes processes
• In multicellular organisms, many are specialized
  to perform specific functions
• Cells are always very small
• The size of multi-celled organisms depends on the
  number of cells NOT their size

7
Organization and Cells, cont.

• Organized at both the molecular and cellular
  levels
• Take in substances from the environment and
  organize them in complex ways
• Specific cell structures (organelles) carry out
  particular functions

8

• In multicellular organisms, cells and groups of
  cells are organized by their function (hierarchy
  of life)
• Atom ? Biological Molecule ? Organelle ? Cell ?
  Tissue ? Organ ? Organ System ? Organism

I dont care what you say thats funny right
there!!! LOL!!

9
1st Level of Organization
Want more? How about the whole hierarchy of Life
from the organism on

• OrganismAn individual living thing that is made
  of cells, uses energy, reproduces, responds,
  grows, and develops

10
2nd Level of Organization

• PopulationA group of organisms, all of the same
  species, which interbreed and live in the same
  place at the same time.

11
3rd Level of Organization

• Biological
• CommunityAll the populations of different
  species that live in the same place at the same
  time and interact (solely biotic in terms of
  composition).

12
4th Level of Organization

• Ecosystem Populations of plants and animals
  that interact with each other in a given area,
  along with the abiotic components (physical and
  chemical) of that area. terrestrial or aquatic

13
5th Level of Organization

• BiosphereBroadest, most inclusive level, i.e.,
  the thin volume of Earth and its atmosphere that
  supports life (5 to 6 miles above surface to
  deepest part of the oceans)

• Earthapplebiosphereskin of apple

14
Response to Stimuli

• Organisms can respond to a stimulus, or a
  physical or chemical change in the internal or
  external environment

15
Homeostasis

• The maintenance of a stable level of internal
  conditions even though environmental conditions
  are constantly changing, e.g., body temperature,
  water content, glucose levels

16
Metabolism

• The sum of all the chemical reactions that take
  in and transform energy and materials from the
  environment

PHOTOSYNTHESIS
17
Metabolism

• ALL energy comes from the SUN (directly or
  indirectly)
• Photosynthesis is the process by which some
  organisms capture the energy from the sun (solar)
  and transform it into energy (chemical) that can
  be used by living things

PHOTOSYNTHESIS
18
Metabolism

• Organisms that make their own food are called
  autotrophs
• Phototrophs use solar energy (photosynthesis)
  to get energy
• Convert H2O and CO2 into sugar and O2
• Chemotrophs use different chemical processes to
  get energy
• Organisms that must take in food to meet their
  energy needs are called heterotrophsConsume
  autotrophs (herbivores), other heterotrophs
  (carnivores) or both (omnivores) for their energy
  needs
• Complex chemicals are broken down and reassembled
  into chemicals and structures needed by organisms
  

19
Growth and Development

• All living things grow and increase in size from
  the division and enlargement of cells

• Development is the process by which an organism
  becomes a mature adult involves cell division
  and cell differentiation, or specialization

20
Reproduction

• Production of new organisms is essential for the
  continuation of a species

• Hereditary information is transferred to
  offspring during two kinds of reproduction
• Sexual reproduction hereditary information
  recombines from two organisms of the same species
• Asexual reproduction hereditary information
  from different organisms is not combined
  original and new organisms are genetically the
  same

21
Evolution or Change Through Time

• Populations of living organisms evolve or change
  through time to better adapt to changing
  conditions

• Charles Darwins SURVIVAL OF THE FITTEST through
  the process of natural selection

22
THEMES IN BIOLOGY

• Diversity and Unity
• Unity in the Diversity of Life
• Three Domains of Life
• Interdependence of Organisms
• Evolution of Life
• Natural Selection

23
Unity in the Diversity of Life

• Genetic code rules that govern how cells use
  the hereditary information in DNA
  (deoxyribonucleic acid makes up our genes or
  instructions for life)
• Presence of organelles carry out all cellular
  activities
• Tree of Life suggests all living things have
  descended with modification from a single common
  ancestor thus, all of life is connected

24
Three Domains of Life

• Bacteria
• Kingdom Bacteria (Eubacteria)
• Archaea
• Kingdom Archaea (Archaebacteria)
• Eukarya
• Kingdom Animalia
• Kingdom Plantae
• Kingdom Fungi
• Kingdom Protists

25
Interdependence of Organisms

• Ecology branch of biology that studies
  organisms interacting with each other and with
  the environment
• Ecosystems communities of living species and
  their physical environments e.g., minerals,
  nutrients, water, gases, heat, etc.

26
Evolution of Life

• Descent with modification process in which the
  inherited characteristics within populations
  change over generations, such that genetically
  distinct populations and new species can develop
• Natural Selection organisms that have certain
  favorable traits are better able to survive and
  reproduce successfully than organisms that lack
  these traits
• Adaptations traits that improve an individuals
  ability to survive and reproduce

27
Scientific Method
28
Scientific Processes and Methods

• 1. Observations/Questioning
• 2. Measuring, Organizing Data, and Classifying
• 3. Hypothesizing -- a testable explanation based
  on experience, reading, and/or previous
  experiments. (NOT A GUESS)
• Inductive Reasoning
• 4. Predicting -- stating in advance the result
  that will be obtained from testing
• Deductive Reasoning (Ifthenstatement)

29
Scientific Method, cont.

• 5. Experimenting -- A controlled procedure for
  testing a hypothesis
• Control Group -- all conditions remain constant
• Experimental Group -- same as control, except for
  ONE factor
• Variable
• Independent Variable - condition that changes
• Dependent Variable - response to changed
  condition
• Data
• Qualitative descriptive
• Quantitative numbers

30
Scientific Method, cont.
31
Scientific Method, cont.

• 6. Organizing and Analyzing Data

32
Scientific Method, cont.

• 7. Inferring Conclusions (concluding from
  evidence collected during experimentation using
  facts and previous knowledge rather than direct
  observtions)
• 8. Modeling and Communicating
• 9. Test and Re-test law or theory formed

33
Scientific Method, cont.

• LAW -- general statement that describes a wide
  variety of phenomena
• If a hypothesis describes HOW things happen and
  continues to be supported by evidence, it becomes
  a law.
• THEORY -- most probable explanation for a set of
  data based on best available evidence
• If a hypothesis describes WHY things happen and
  continues to be supported by evidence, it becomes
  a theory.

34
Scientific Method -- Example

• Observations
• Fish populations in Twin Lakes are declining.
• The pH (acidity) of the water in the lakes is
  dropping to 4.2.
• One hundred miles west of Twin Lakes is a power
  plant that is burning tons of coal every year,
  releasing sulfur dioxide into the air.

35
Problem

• Twin Lakes -- Acid Rain Problem

100 miles
East Branch
West Branch
Power Plant
36
Questioning/Hypothesizing(Inductive Reasoning)

• Question Is there a link between the power
  plant, the pH of the lake, and the fish decline?
• Hypothesis If acid rain falling on Twin Lakes
  is related to fish reproduction, then increasing
  acid rain amounts will cause the fish to have
  poor reproduction.

37
Experiment

• Experiment
• Twin Lakes is a lake in the mountains that can be
  divided by a barrier.
• A complete inventory will gather baseline data.
• One arm of the lake, on the east side of the
  barrier, will be treated with sulfuric acid to
  reduce the pH to 4.0.
• The west arm of the lake will be left alone,
  other than monitoring.

38
Experiment

• Twin Lakes -- Acid Rain Problem

100 miles
East Branch
West Branch
Barrier
Power Plant
Acid Rain Added
No Acid Added
39
Results

• East Branch
• Fish stop reproducing.
• West Branch
• No change in fish reproduction.

40
Conclusion

• The power plant emits sulfur dioxide into the air
  which combines with rain to produce acid rain.
  The addition of this acidic rain to the lakes
  lowers the pH and causes the fish to stop
  reproducing. This results in declining fish
  populations and jeopardizes the survival of the
  fish.