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WorksheetsBiotic Factors of Ecology - 7th grade
Total questions: 40
Worksheet time: 32mins
Name
Class
Date
1.
Humus is part of the soil within an ecosystem. Worms often act as decomposers within that ecosystem. Decomposition is the worm's ___ in the ecosystem.
a)
niche
b)
habitat
c)
biome
d)
ecosystem
2.
Kudzu takes over almost any area in which it germinates. Kudzu is considered to be a(n) __.
a)
invasive species
b)
predator
c)
native species
d)
prey
3.
Levels of ecological organization in order from largest to smallest would be _____.
a)
species, population, community, ecosystem, biome
b)
biome, ecosystem, community, population, species
c)
biome, ecosystem, population, community, species
d)
population, species, community, biome
4.
The picture below shows a ____.
a)
population
b)
community
c)
ecosystem
d)
biome
5.
The graph illustrates what has happened over an 8 year period, when non-native Nile perch were introduced to Lake Malawi in Africa. Based on the data, what recommendation would you make to African biologists?
a)
There is not enought information on the graph
b)
Reduce both fish populations, or they will starve one another out.
c)
Remove the pike cichlids, as they are competing with the Nile perch.
d)
Remove or reduce the Nile Perch as quickly as possible, as it is out competing the Pike Cichlid
6.
The picture below shows ____.
a)
an ecosystem
b)
a community
c)
a species
d)
a biome
7.
A wolf changes his predation patterns in the winter and stops eating his normal prey, deer, by preying on salmon in a nearby stream. What is a reason why the wolf would ignore the deer and eat salmon in this situation?
a)
The deer population has increased due to over abundance of producers for them to eat.
b)
The deer population has migrated tot he south and are not availale for the wolves any longer.
c)
Wolves get tired of being injured by the hooves of deer during predation.
d)
Salmon mate in the spring in streams in the ZNortheast, so ther is an abundance of salmon in the area.
8.
How would this ecosystem most likely be affected if the eagle was removed from the area?
a)
There would be a decrease in the number of butterflies.
b)
There would be no change, because it is a food web, not chain.
c)
The number of snakes would decrease drastically.
d)
The number of butterflies would grow out of control.
9.
Which statement about this energy pyramid is correct?
a)
Energy is not transferred from one level to the next level in the pyramid.
b)
All of the energy is only at the bottom of the pyramid.
c)
Energy is transferred, and the bottom level of the pyramid has the most energy.
d)
Most of the energy is at the top of the pyramid.
10.
The colors in the map below would most likely be used to identify ___.
a)
the biomes around the world
b)
the communities around the world
c)
the species around the world
d)
the populations around the world
11.
What most likely caused the decrease in the lynx population around 1921?
a)
There had been an increase in the snowshoe hare population.
b)
There had been a decrease in the snowshoe hare population.
c)
The lynx only had an abundance of food that year.
d)
There is not enough information in the graph to determine an answer.
12.
Based on this graph, what might best explain the change in the deer population from 2000 to 2001?
a)
an increase in the emigration of deer
b)
an increase in the immigration of deer
c)
a decrease in the birth rate for deer
d)
an increase in the death rate of the deer
13.
In this energy pyramid 10,000 joules of the energy is produced by the producers. What would you predict would be the level of energy for the level 2 consumers?
a)
30,000 joules
b)
20,000 joules
c)
100 joules
d)
zero
14.
What type of symbiotic relationship exists between a bee and a flower?
a)
mutualism
b)
competition
c)
parasitism
d)
commensalism
15.
What type of symbiotic relationship exists between this sea turtle and the barnacles attached to his shell?
a)
competition
b)
commensalism
c)
parasitism
d)
mutualism
16.
What type of symbiotic relationship exists between this tick on a rabbit?
a)
competition
b)
predator-prey
c)
commensalism
d)
parasitism
17.
In this picture two hartebeest are locking horns and fighting over their territory. What type of symbiotic relationship is this?
a)
mutualism
b)
parasitism
c)
commensalism
d)
competition
18.
This graph shows changes in two populations. What relationships do you observe between the two populations?
a)
When the prey population decreases it is followed by a decrease in the predator population.
b)
When the prey population increases, it is followed by a decrease in the predator population
c)
When the predator population increases it is followed by an increase in the prey population.
d)
When the predator population decreases it is followed by a decrease in the prey population.
19.
If their are 30 prairie dogs in a field that is 10 square meters, what is the population density?
a)
3 prairie dogs per square meter
b)
300 prairie dogs per square meter
c)
.03 prairie dogs per square meter
d)
30 prairie dogs per square meter
20.
Which of the following is not a documented invasive species in the United States?
a)
Zebra mussels which have impacted the aquatic marine ecosystems of the Great Lakes.
b)
Red fire ants of South America that have infiltrated the southeastern US.
c)
Kudzu which is a vine that when left uncontrolled will eventually grow over almost any fixed objects in its path.
d)
Arrowfeather threeawn grass which grows naturally throughout most states east of the Great Plains.
21.
The place where an organism lives and that provides the things the organism needs is called its ___.
a)
niche
b)
habitat
c)
community
d)
biome
22.
The largest population that an environment can support is called its ___.
a)
limiting factors
b)
immigration total
c)
carrying capacity
d)
birth rate
23.
An organism's specific role within an ecosystem is called its ___.
a)
ecosystem
b)
emigration
c)
niche
d)
carrying capacity
24.
When a jellyfish paralyzes a tiny fish with its poisonous tentacles, the jellyfish is the ___.
a)
predator
b)
prey
c)
host
d)
parasite
25.
The measurement of the approximate number of organisms that live in a given area is known as ____.
a)
population density
b)
limiting factor
c)
community
d)
none of these
26.
Would you expect the population of ants or elephants to be larger? Why?
a)
ants because they are bigger
b)
elephants because they need more space
c)
ants because they are smaller
d)
elephants because of their size
27.
In 1976 what most likely happened to cause a change in this pheasant population?
a)
Quail migrated into this area and competed with these pheasants for food.
b)
More pheasants immigrated than usual.
c)
The pheasants were able to find more resources than usual.
d)
There was an unusual increase in the birth rate.
28.
Tropical rain forests have a very hot and humid climate with approximately 200 inches of rain per year. If we are referring to rain forests as a whole, what term would we use?
a)
community
b)
ecosystem
c)
population
d)
biome
29.
These penguins can reproduce with one another. This means they are part of the same ____.
a)
community
b)
ecosystem
c)
species
d)
biome
30.
What would be the correct flow of energy in a food chain or energy pyramid?
a)
producer > primary consumer>secondary consumer> tertiary consumer
b)
producer<primary consumer<secondary consumer<tertiary consumer
c)
tertiary consumer>secondary consumer>primary consumer>producer
d)
primary consumer>secondary consumer>tertiary consumer>producer
31.
Which would be an appropriate food chain that could be produced from this food web?
a)
grass > catepillar > bird > eagle
b)
eagle > bird>snail > grass
c)
grass > lizard > bird > eagle
d)
grass > catepillar > snail > eagle
32.
Wild hogs were brought to the US by Europeans as early as the 1500s. The collective yearly cost of agricultural damage and control of these animals alone would conservatively be in the tens of millions of dollars. Wild hogs are considered to be ___.
a)
invasive species
b)
native species
c)
extinct
d)
endangered species
33.
Our planet is divided into large geographic areas based on differences in climate. These areas are called ____.
a)
biomes
b)
communities
c)
ecosystems
d)
habitats
34.
What is the independent variable for this graph?
a)
time
b)
number of predators
c)
number of prey
d)
there is no independent variable
35.
Jeff tested to see which brand of dog food would help his dog to maintain a constant weight. What was his dependent variable?
a)
brands of dog food
b)
species of dog
c)
amount of food the dog ate
d)
the dog's weight
36.
Leslie wanted to know which brand of battery would last longer in her flashlights. Which statement below is TRUE?
a)
Leslie's independent variable was how long the flashlight stayed on.
b)
Leslie's dependent variable was the amount of time the flashlights stayed on.
c)
Leslie's dependent variable was the brand of batteries.
d)
Leslie should only do one test to prove her hypothesis.
37.
Mrs. Jennings, our science teacher, said we should always repeat our experiment even if we know we did not make a mistake. Is she correct? Why or Why not?
a)
She is correct, you need to increase the validity and reliablity of your data by repeating your experiment several times.
b)
She is incorrect. She just wants you to take more time, so she doesn't have to teach.
c)
She is incorrect, as long as you know you did not make any mistakes.
d)
No. She is crazy!
38.
Andy wanted to know if taking vitamins would help a person grow taller. He and his twin sister measured their height at the beginning of 7th grade and they were the same height. Andy took vitamins all year and his sister did not. His sister grew 3 inches taller than him that year. Andy concluded that taking vitamins stunted his growth. Which statement below is true?
a)
Andy's data is inconclusive because he did not test enough people. His sample size was too small.
b)
Andy was correct, because his sister grew taller than him and did not take any vitamins.
c)
Andy's sister was already taller than him.
d)
Andy's sister was taller than him because his mother is taller than his father.
39.
Students who study longer make better grades.
What is the independent variable for this hypothesis?
What is the independent variable for this hypothesis?
a)
grades
b)
amount of time spent studying
c)
grade level
d)
gender
40.
All food chains and food webs begin with ____.
a)
primary consumers
b)
producers
c)
secondary consumers
d)
decomposers
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