Ecosystems
Unit 2: Population Balance
Pre-Test
Teachers’ Edition
1.
Populations of species are connected to each other by
(Objective 2; answer – C)
A.
B.
C.
D.
E.
interspecies communication
territorial boundaries
food chains
sources of shelter
behavior
2.
The common outcome for all members of a food web is
(Objective 2; answer - E)
A.
B.
C.
D.
E.
3.
4.
.
they all are omnivorous
they all can be carnivorous
less energy is required to maintain more complex species
all energy is exchanged from one species to another without any losses
when they die, they are converted back to nutrients
In order for a species to survive, it must be
(Objective 2; answer - B)
A.
B.
C.
D.
E.
.
to withstand change.
composed of similar individuals
large enough
growing
very complex
fast enough
A species is best defined as: (Objective 1; answer – C)
A.
B.
C.
D.
E.
animals that live in the same area.
individuals that can communicate with each other.
individuals that can produce fertile offspring.
plants that have similar characteristics such as flower color and number of
leaves.
individuals that share the same level on the food chain.
5.
One characteristics of a population is its density, which is described as
. (Objective 1; answer – B)
A.
B.
C.
D.
E.
the number of different species in a given area
the number of individuals of a species in a given area
the total number of animals present
the size of families living in an area
the range of ages that exist in a population
6.
A population with a very low density is at risk of extinction from
(Objective 3; answer – B)
A.
B.
C.
D.
E.
7.
genetic mutation
disease
lack of shelter
overgrowth
starvation
The term for replacement of grasses in a field with shrubs and trees is called
. (Objective 2; answer – B)
A.
B.
C.
D.
E.
natural selection
succession
procession
natural development
progression
8.
One of the main ways for a species to assure its own survival is to
(Objective 1; answer - B)
A.
B.
C.
D.
E.
9.
.
.
avoid disease
reproduce
make shelters
avoid predators
use tools
If the density of a population increases above its normal levels, the stability of the
population
. (Objective 3; answer – D)
A.
B.
C.
D.
E.
rapidly increases
remains unchanged
is not affected
decreases
slowly increases
10.
If the number of deer in an area increases above normal, the number of
will decrease. (Objective 3; answer – A)
A.
B.
C.
D.
E.
11.
Which of the following results is likely to occur if too few predators are present in
an ecosystem? (Objective 3; answer – A)
A.
B.
C.
D.
E.
12.
plants
predators
prey
young deer
female deer
Fields would lose all of their grasses due to overgrazing.
Offspring born to predators would have very little food.
Predators would die out after they kill of the prey species.
Prey species would lose their fear of predators.
Predators would form new species.
If you wanted to know the number of butterflies in your hometown, you catch
some, mark them, then let them go. After catching and marking 1000 butterflies,
you release them. Later, you catch 1000 more. Of those, 30 are marked and from
the original group. About how many butterflies are in your area? (Objective 1;
answer – D)
A.
B.
C.
D.
E.
1000
3000
10,000
33,000
30,000,000