3rd 9weeks Mid-term Study
Guide Answers
7th Science
Ely, Hoyman, Jackson
1. What is the process in which a plant or animal
species adapts to its environment called?
– adaptation
2. What is the process of passing beneficial traits
(traits that help an organism to survive) down to
the next generation called?
– Natural Selection
3. What are the 4 steps of natural selection?
1) overproduction – producing more offspring
than can possibly survive.
2) inherited variation – every individual has its
own traits. Similar, but not identical to
parents.
3) struggle to survive – some individuals have
traits better adapted to environment.
4) successful reproduction - better adaptations are
passed down to next generation.
4. Give an example of selective breeding. What
makes selective breeding different from natural
selection?
– Breeding dogs, human breed for the “better traits”
that are wanted
5. What do Geologists study to help them learn
what organisms were like in the past?
– Fossils
6. What process do plants use to turn the suns
energy into food?
– Photosynthesis
7. What are the 5 levels of the organization of the
environment (in order from least to greatest)?
1. Individual Organism
2. Made of similar organisms; makes a population
3. Made of different populations; makes a community
4. Made of a community and its abiotic environment, which forms an
ecosystem
5. All ecosystems, which forms Biosphere
8. Describe each of the following: producer, consumer,
decomposer
•
•
•
Producers: use direct sunlight to make food
Consumers: eat other organisms to get energy
Decomposers: get energy by breaking down dead
9. What is the difference between a herbivore and a
carnivore?
• herbivore: only eats plants
• carnivore: only eats animals
10. In any food web, what do the arrows represent?
•
Predators (the item doing the eating)
11. Put the following in order to correctly show the
movement of energy in a food chain. Producer, sun,
scavengers and decomposers, consumers.
•
Sun, producer, consumer, scavengers, decomposers
12. What is the primary source of energy in all food
webs?
•
SUN
13. Name two examples of decomposers.
•
Bacteria, fungi
14. What do the terms biotic factors and abiotic factors mean?
–
–
Biotic factors are all living factors
Abiotic factors are the nonliving factors
15. What are the 3 types of symbiotic relationships?
–
Mutualism, commensalism, parasitism
16. Describe a tundra’s environment. (temperature, climate,
animals, plants)
–
Cold temperatures and little rainfall, animals with special
adaptations such as polar bear
17. Describe a desert’s environment. (temperature, climate,
animals, plants)
–
Very hot and dry, plants grow separated from each other,
animals are active at night
18. Describe a grassland’s environment. (temperature,
climate, animals, plants)
•
Few trees, has dry seasons, prairie dogs, flowering plants
19. Describe a rainforest’s environment. (temperature,
climate, animals, plants)
•
Wet, cool, covered by tree canopy, largest diversity in plants
and animals
20. Describe a deciduous forest’s environment.
(temperature, climate, animals, plants)
•
Mild temperature, plenty of rain, trees lose leaves to help
conserve water in dry season, much like where we live
21. In a desert ecosystem, would you expect to find more
insects or more birds of prey (hawk)? Why?
• Insects, heat and water resources
22. What would happen to the rest of the organisms in an
ecosystem if one organism was removed? Explain.
•
It could change the eating habits, cause some to die out
and change the web completely