Download Review – 8th Grade – 5th Six Weeks Test

Review
ECOLOGY:
1. Define the following:
a. Population- a group of individuals of the same species
b. Ecosystem- the interactions between the biotic and abiotic factors in an area
c. symbiotic relationship- a close relationship between two species
2. Describe the relationship between predator and prey.
Predators hunt and consume prey (prey provide energy for predators)
3. Draw a simple food chain. Describe what the direction of the arrows represents.
In a food chain the arrows represent the flow of energy through the ecosystem
4. Explain the difference between a habitat and a niche.
A niche is the role of an organism in its’ habitat (where it lives)
5. What is a primary consumer?
A primary consumer is a 1st level consumer on the bottom of a food pyramid.
These organisms are HERBIVORES
FOOD CHAINS AND FOOD WEBS:
6. Food chains are more than “who eats whom.” They also show the flow, or passing, of ____ENERGY______
from one organism to the next.
• Does energy increase or decrease as it passes through a food chain?______DECREASE____
7. What do plants make during photosynthesis?
Glucose (sugar-the plant’s food)
8. Review the three types of symbiotic relationships and be able to give an example for each:
Mutualism- both species benefit-crocodile and plover bird
Commensalism-one species benefits and the other is unaffected-shark and remora fish
Parasitism-one species benefits while the other is harmed-tick and animal hos
9.. Define the following:
a. omnivore-eats both plants and animals
b. herbivore-eats only plants
c. carnivore-eats only meat
d. decomposer-breaks down dead matter
e. producer-autotroph-makes its’ own food
10. Explain the difference between an autotroph and a heterotroph. An autotroph makes its’ own food. A
heterotrophy relies on other organism for food
11. Describe the theory of natural selection as Charles Darwin sees it.
Natural Selection is the process through which those organisms that are best suited (adapted) to their
environment are better able to survive and reproduce. This means they get to pass their genetic information
on to the next generation of their species. Also, organisms that are not well adapted to their environment will
be less likely to reproduce, meaning their genetic traits will show up less frequently in future generations.
12. Give an example of an adaptation that can allow an organism to be more fit (better suited) for its
environment.
Bird beak shape is an example of an adaptation that can allow an organism to be better suited to its
environment. The shape of the beak helps the bird with the type of food it eats. For example birds that have
to crack the shells of hard nuts, will have a thick strong beak compared to the beaks of birds that eat small
seeds or bugs.
13. What is camouflage?
Camouflage is the ability to blend in to your environment (it is an adaptation)
14. Describe the difference between biotic and abiotic factors.
Biotic describes anything that is living or ever was alive (trees, sticks, animals). Abiotic means that the thing
was never alive (wind, sunlight, temperature)
15. How does competition over limiting factors help control population size?
Organisms compete for limiting factors such as space, water, available food and mates. This competition
means that only the best adapted will be able to get everything they need to survive and reproduce, this helps
to control population size. If the population outgrows what the resources will support, then some organisms
will die.
16. What is carrying capacity? Carrying capacity is the number of organisms that an area can support (keep
alive)