1. ZOOLOGY—STUDY OF ANIMALS
Life began over 600 million years ago
Evolution of
-multicellularity, coelom, vertebrae, homeothermy

2. Fundamental Properties of Life
Does Life Have Defining Properties?
What is life?

3. Fundamental Properties of Life
Does Life Have Defining Properties?
What is life?
No simple definition
The history of life shows extensive and ongoing change called evolution
Answer must be based on the common history of life on earth

4. 8 General Properties of Living Systems
1. Chemical Uniqueness:
Living systems demonstrate a unique and complex molecular organization
Small molecules are assembled into macromolecules:
Nucleic Acids
Proteins
Carbohydrates
Lipids

5. 8 General Properties of Living Systems
Although living systems are composed of the same kinds of atoms obeying the same fundamental laws of chemistry as nonliving matter, the organizational structure of the macromolecules makes them unique

7. 8 General Properties of Living Systems
2. Complexity and Hierarchical Organization:
Living systems demonstrate a unique and complex hierarchical organization
In living systems there exists a hierarchy of levels that includes:
Macromolecules
Cells
Organisms
Populations
Species

8. 8 General Properties of Living Systems
3. Reproduction:
Living systems can reproduce themselves
At each level of the biological hierarchy living forms reproduce to generate others like themselves:
Genes replicated to produce new genes.
Cells divide producing new cells.
Organisms reproduce, sexually or asexually, to produce new organisms
Populations may fragment to produce new populations
Species may split to produce new species

9. 8 General Properties of Living Systems
4. Possession of a Genetic Program:
A genetic program provides fidelity of inheritance
DNA: Long, linear, chain of nucleotides containing genetic information
Sequence of nucleotide bases in DNA determines the order of amino acids in proteins
Genetic Code: correspondence between base sequences in DNA and the sequence of amino acids in a protein

11. 8 General Properties of Living Systems
5. Metabolism:
Living organisms maintain themselves by acquiring nutrients from their environments
Metabolic processes include:
Digestion
Energy production (Respiration)
Synthesis of required molecules and structures by organisms

12. 8 General Properties of Living Systems
Metabolism is often viewed as an interaction of destructive (catabolic) and constructive (anabolic) reactions
The most fundamental anabolic and catabolic chemical processes used by living systems arose early in the evolutionary history of life

14. 8 General Properties of Living Systems
6. Development:
All organisms pass through a characteristic life cycle
Development describes the characteristic changes that an organism undergoes from its origin to its final adult form

16. 8 General Properties of Living Systems
7. Environmental Interaction:
All animals interact with their environments
Ecology: The study of organismal interaction with an environment
All organisms respond to environmental stimuli

18. 8 General Properties of Living Systems
8. Movement:
Living systems and their parts show precise and controlled movements arising from within the system
Living systems extract energy from their environments permitting the initiation of controlled movements

19. 8 General Properties of Living Systems
Movements at the cellular level are required for:
Reproduction
Growth
Responses to stimuli
Development in multicellular organisms
On a larger scale:
Entire populations or species may disperse from one geographic location to another over time

20. Zoology As Part of Biology
Characteristics of Animals:
Multicellular
Eukaryotes: cells contain membrane-enclosed nuclei
Heterotrophs: Not capable of manufacturing their own food and must rely on external food sources
Cells lack cell walls and photosynthetic organelles
And most can
5. Reproduce sexually
6. Move

21. Principles of Science
The scientific method may be summarized as a series of steps:
Observation
Question
Hypothesis Formation
Empirical Test
Controlled Experiment
Includes at least 2 groups
Test Group
Control Group
Conclusions
Accept or reject your hypothesis
Publications

22. Principles of Science Hypothesis:
Potential answers to questions being asked
Derived from prior observations of nature or from theories based on such observations
Often constitute general statements about nature that may explain a large number of diverse observations
If a hypothesis is very powerful in explaining a wide variety of related phenomena, it attains the level of a theory

23. Principles of Science
Powerful theories that guide extensive research are called paradigms
The refutement and replacement of a paradigm is known as a scientific revolution
Two major paradigms that guide zoological research:
Darwin’s Theory of Evolution
The Chromosomal Theory of Inheritance