1. Biology: Exploring Life
Chapter 1

2. Hierarchy of Life
Atom Molecule Macromolecule Organelle Cell* Tissue Organ Organ System Organisms Population Community Ecosystem Biosphere
Emergent properties-characteristics that arise from a more encompassing hierarchal level that was not present in the previous level

3. Cells are the structural and functional units of life
Life emerges at the level of the cell
Two main types of cells
Prokaryotic cells
lack membrane bound organelles
simple and small, range in size from 1-10 µm
ex. bacteria
Eukaryotic cells
Have membrane bound organelles;
Can be a single cell, most are multicellular; µm
ex’s. plants, animals, fungi and protists

4. Prokaryotic cell Eukaryotic cell Membrane Organelles DNA (no membrane
around nucleus)
Membrane
Nucleus = nuclear
membrane
around DNA)
Organelles

5. True or False?
1. Life emerges at the level of the cell. 2. Prokaryotic cells are smaller and simpler than eukaryotic cells.

6. What is Life? ENERGY PROCESSING ORDER REGULATION GROWTH & DEVELOPMENT
RESPONSE TO
ENVIRONMENT
REPRODUCTION
EVOLUTIONARY
ADAPTATION

7. Three Domains of Life

8. Domain Eukarya Includes Four Kingdoms:
K. Protista
K. Plantae
Tree of Life Web Project:
Video of an example from each kingdom
K. Fungi
K. Animalia

9. Living Organisms Interact with their Environments
To be successful, an ecosystem must recycle chemicals necessary for life & move energy through the ecosystem
Biotic and Abiotic components must interact to accomplish this

10. Living Organisms Interact with their Environments
Biotic components
Abiotic components
Producers: Photosynthetic organisms that provide food for a typical ecosystem
Consumers: Eat plants (or eat animals that profit from/eat plants)
Chemicals & nutrients required for life
Examples: Oxygen, Carbon dioxide, water, visible light, etc.

11. Producers Consumers Ecosystem Sunlight Cycling of chemical nutrients
Heat
Chemical energy
Consumers
Figure 1.2 The cycling of nutrients and flow of energy in an ecosystem.
Heat

12. The unity of life is Based on DNA and a common genetic code
All cells have DNA
DNA is the chemical substance of genes
A gene is a discrete unit of inheritance that transmits information from parents to offspring
DNA is composed of two strands, coiled in a helix

13. Evolution Explains the Unity and Diversity of Life
In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection
Darwin emphasized two points:
1. descent with modification
2. natural selection is the mechanism of evolution

14. Darwin started with two observations
A population has genetic variation
2. Overproduction of offspring
Population with varied inherited traits 1
Figure 1.6B An example of natural selection in action.
Elimination of individuals with certain traits
Reproduction of survivors

15. Evolution Explains the Unity and Diversity of Life
Darwin inferred that unequal reproductive success would lead to the accumulation of favorable traits in a population
Figure 1.6C Examples of adaptations to different environments.
Pangolin:
Killer whales:
Killer whale
Pangolin

16. Evolution Explains the Unity and Diversity of Life

17. THE PROCESS OF SCIENCE

18. Scientists Use Two Main Approaches to Learn About Nature
Two approaches are used to understand natural causes for natural phenomena
Discovery science which uses verifiable observations and measurements to describe science
Hypothesis-based science—uses the data from discovery science to explain science.
This requires proposing and testing of hypotheses

19. Hypotheses and Theories
What is the difference between a theory and a hypothesis?
A hypothesis is a proposed explanation for a set of observations
The hypothesis must be testable and falsifiable
A theory is supported by a large and usually growing body of evidence

20. Observations Question
Figure 1.8A An example of hypothesis-based science.

21. Observations Question
Hypothesis 1: Dead batteries
Hypothesis 2: Burned-out bulb
Figure 1.8A An example of hypothesis-based science.

22. Hypothesis 1: Dead batteries Hypothesis2: Burned-out bulb
Observations
Question
Hypothesis 1: Dead batteries
Hypothesis2: Burned-out bulb
Prediction 1: If the batteries are replaced
then it will fix problem
Prediction 2: If the bulb is replaced
then it will fix problem
Figure 1.8A An example of hypothesis-based science.

23. Observations Test predictions
Question
Hypothesis 1: Dead batteries
Hypothesis2: Burned-out bulb
Prediction 1: If the batteries are replaced
then it will fix problem
Prediction 2: If the bulb is replaced
then it will fix problem
Figure 1.8A An example of hypothesis-based science.
Test predictions

24. Observations Test predictions Test falsifies hypothesis
Question
Hypothesis 1: Dead batteries
Hypothesis2: Burned-out bulb
Prediction 1: If the batteries are replaced
then it will fix problem
Prediction 2: If the bulb is replaced
then it will fix problem
Figure 1.8A An example of hypothesis-based science.
Test predictions
Test falsifies hypothesis
Test does not falsify hypothesis