Unit 8 – EOC PREP Name: __________________________________________________ECOLOGY REVIEW Date: _______________________________ Period: ___________

ECOLOGY REVIEW

CARBON CYCLE

FOOD WEBS : Remember, the arrow points from the PREY PREDATOR

the food goes into its mouth!producer primary consumer secondary consumer tertiary consumer RULES: 1. When prey decrease, predators decrease2. When predators decrease, prey increase

NITROGEN CYCLE1. 80% of the Earth’s atmosphere is nitrogen (N2) but

plants and animals cannot use nitrogen in this form. 2. Nitrogen-fixing bacteria in the soil convert atmospheric

nitrogen (N2) into ammonia (NH3)/nitrates (NO3-)—a

form plants can absorb to make different amino acids. 3. Animals eat the plants to obtain nitrogen to make their

own proteins. 4. When plants and animals die, denitrifying bacteria

convert the nitrogen (ammonia/nitrates) back into atmospheric nitrogen (N2) and release N2 into the atmosphere: “denitrification”

Atmospheric CO2

Photosynthesis CO2 in air decreases

Respiration CO2 in air increases

Burning of Fossil Fuels

CO2 in air increases

Deforestation CO2 in air increases

EVOLUTION REVIEW

Biodiversity: lots of different plant and animal species in an environmentWhy is it a good thing? better able to adapt to environmental changes

Evolution occurs through natural selection (“survival of the fittest”).What do we know…

1. There is a struggle to survive. 2. There is genetic variation within every population of species.

the best adapted organism to an environment will survive and reproduce, passing their fit genes onto offspring, especially after changes to the environment

over time this can lead to speciation, or the creation of a new species that cannot interbreed with its ancestors

Why do giraffes have long necks? Some giraffes had longer necks while others had shorter necks; the giraffes with longer necks were able to eat more leaves, survive, and reproduce. Over millions of years, this led to a new species with long necks.

What increases the rate of evolution? 1. High genetic mutation rate2. Fast reproductive rate3. Frequently changing environments4. Small population size