1. Unit 15 – Ecology and Plant Life Functions

2. Ecology – the study of living organisms and their interactions in the environment. Ecosystem – community of living and nonliving things interacting as a system

3. Abiotic vs Biotic Factors
Abitoic (non-living) and Biotic (living) factors are what make-up an Ecosystem.
Organisms are placed into a food chain and then ecological levels.
organism level of study: studying one specific organism in a food chain
The following are a few of the major ecological levels:
Population – a group of organisms that are members of the same species and share a common gene pool
Community – the various populations of living organisms in an ecosystem
Biosphere – all areas of the Earth that sustain life

4. Ecological Levels in Order

5. Life Influences Life
There are many different types of relationships within ecosystems.
Symbiosis- the relationship between two different species. Examples are #1 mutualism, #2 parasitism, and #3 commensalism.
Mutualism- both species benefit from each other. +/+
- Example: algae and fungus. Algae makes the food for both, fungus provides shelter for both
Parasitism- one species is harmed where the other is benefited. +/-
- Example: ticks and humans. Ticks bite humans and suck out the blood

6. Predator vs Prey
Predators are organisms who hunt to kill other organisms, their prey.
If the prey population increases  predator population will increase
If the prey population decreases  predator population will decrease
If the predator population decreases  prey population will increase
If the predator population increases  prey population will decrease
Habitat: where an organism lives
Niche: the organism’s role in the environment.
Ants gathering food for their ant family back home.

7. Population Studies
Ecologists use sampling to obtain a total count of the population by counting the organisms in a small area and multiplying that by the total area.
Example: # of organisms in a small area = 50 and total area = 100 sq meters. The total # of organisms in the total area is 5,000.
Ecologists use quadrant studies to study the species diversity in an area, otherwise known as biodiversity.

8. Examples of Growth Patterns:
Limiting Resources – energy, water, nutrients
Exponential
Population
Growth
Dynamic Equilibrium –
staying near Carrying
Capacity
Max amount of
Organisms in
One ecosystem.

9. Human Age Structure Graphs- showing stable or rapid growth
Rapid growth: large number of children Slow growth: shaped like a tower – even distribution – stable

10. Food and Energy Pyramid
5 cal
50 calories
500 calories
5,000 calories

11. Note: Decomposers recycle the nutrients at every trophic level.

12. Carbon Cycle Cellular Respiration breaks down
glucose with oxygen to produce
Carbon dioxide, water, and ATP.
Plants use sunlight and carbon
dioxide to create photosynthesis
for food and energy.
Photosynthesis removes carbon
dioxide from the atmosphere.
Carbon Dioxide is released into
the atmosphere by animals.

13. Global Warming – the imbalance of the carbon cycle that leads to increase temperatures on Earth.
Decrease in global forests – less photosynthesis occurring to remove carbon dioxide from the atmosphere.
Increase in fossil fuels – more carbon dioxide released into the atmosphere.

14. Nitrogen Cycle
Bacteria recycles nitrogen from the atmosphere and dead organisms from the soil.
Nitrogen is an important part of
nucleic acids and proteins (two of the four macromolecules).

15. Human Impact on the Environment
Cause
Effect
Pesticide use
Fossil Fuel use
Human growth
Non-native species
Bioaccumulation – accumulation in an organism. Pesticides are increasing as you get higher in the food chain.
Acid precipitation – chemicals attach to water molecules and fall as rain/snow. Sulfur and Nitrogen are the chemicals from fossil fuels.
Habitat destruction – natural habitats destroyed for growth to create more space/room.
Invasive species kill and crowd out important species natural to the ecosystem.

16. Plants Illustrating Evolution of Life
Plants today have evolved from algae that lived in the ocean.
Moss Ferns Angiosperms
-non-vascular -vascular tissue Gymnosperms -vascular tissue
-spores, not seeds -spores, not seeds - vascular tissue -seeds
-no flowers -no flowers -seeds -flowers
-no flowers

18. Self Pollination vs Cross Pollination

19. 5 Methods of Seed Dispersal