Name: ____________________________________
I.
MULTIPLE CHOICE
Fill in the appropriate bubble on the scantron for the following questions. (1pt each)
1. Which of the following is an example of an organism interacting with an abiotic factor?
a. Cows eating grass.
c. Sun warming and melting ice into liquid water.
b. Rocks adding nutrients to the soil.
d. Plants absorbing water through their roots.
2. Which of the following is an example of primary succession?
a. A forest recovering after a fire
c. Moss growing on the side of your house
b. Tall grass growing after a farm field is abandoned d. None of the above
3. Sea otters prevent sea urchins from depleting the kelp population. Kelp supplies a variety of ocean organisms with
food. The most accurate, ordered, definition for each species (in the following order) is: sea otter –sea urchin – kelp
a. Generalist – host – keystone
c. Native – nonnative - parasite
b. Keystone – predator – prey
d. Predator – producer – predator
Use the graph to the right to answer questions #4&5
4.
What is the average number of green insects collected?
a. 4
b. 1
c. 3
d. 9
5. Which of the following is a reasonable inference
(conclusion) for why orange insects were caught the most?
a. The color blended in with the background.
b. The color stood out among the background.
c. There were less orange insects than other colors.
d. Everybody likes the color orange.
6. What best describes the following situation? Butterflies that have traditionally lived their lives in Southern Mexico
have begun to migrate northward, into Texas. Scientists attribute this behavior to global climate change, claiming
these butterflies are a(n)
a. Predator
b. native species
c. Indicator species
d. keystone species
7. In the food web to the right, the SHREW is a _____________ and if
removed will cause_________.
a. Secondary consumer; the snake population to decline due to
lack of food
b. Secondary consumer; the rabbit population will increase
because there will be more food available
c. Primary consumer; the mouse population to go up because
there will be less competition
d. Primary producer; the insect population to increase because it
has less predators.
8. A J-shaped population growth will suffer a dieback (crash) because of:
a. Low birth rates
c. exceeding carrying capacity
b. immigration
d. nothing; J-shaped growth
continues forever
9. An r-strategist generally
a. has a low reproductive rate (offspring / lifetime)
b. reproduces later in life, typically only once or twice
c. has a short-life span and reproduces quickly
d. gives much parental care to its offspring
10. The estimated carrying capacity of deer in Upper Dublin Township is 50. If the population reaches 500, what is the
LEAST likely thing to happen?
a.
Some township residents will begin to feed the deer to prevent starvation.
b.
The population will decrease due to increased car accidents.
c.
The population will continue to increase in size.
d.
The deer will leave Upper Dublin and emigrate to Abington looking for food.
For questions 11- 16 answer with one of the labels, a-e. To clarify, the organisms of the relationship you should focus
on are in bold. (Each label may be used once, more than once, or not at all.) The answer to #2 is c.
a. mutualism
b. commensalism
c. competition
d. parasitism
e. predation
11. A colony of deep sea polyps “becomes” the shell for a hermit crab providing a life-long shell for the crab and
gaining transport for itself in the process. a
12. A “herd” of hyenas often follows a lion and waits until the lion is finished eating its prey before eating the remains. b
13. Ranchers killed hundreds of prairie dogs so their cattle could have the grass on the range. c
14. Plant detritus provides most of the food for decomposers and soil-dwelling detritus feeders such as earthworms. The
detritus feeders provide nutrients for new plant growth. a
15. At dusk, the bolas spider twirls a thread that ends in a drop of liquid silk. Male moths are attracted by a chemical in
the silk, and become caught on the sticky blob. The spider hauls in the moths and chows down. e
16. Bedbugs are a recent U.S. problem…these creatures live in complex carbohydrates (your mattress) and feed on the
blood of any mammal in the house. d
Questions 17-20: For each of the following factors, state what would happen to the population size.
a. Increase
b. Decrease
c. Stay the same
17.
18.
19.
20.
plants receive unlimited favorable light a
the habitat becomes unsuitable b
emigration rate exceeds immigration rate b
birth rate exceeds death rate a
21. In a given year, there are 750 births, 625 deaths, 1000 immigrants and 1125 emigrants. The population is___.
a. Growing
c. Shrinking
b. Staying the same
d. Cannot be determined
22. Which does NOT correctly match the country with the approximate current population total?
a. United States – 318 million
b. China – 1.3 million
c. India – 1.2 billion
23. Between 1963 & present, the rate of the world’s annual growth rate has _____________ and the total world
population has _____________________.
a. Increased; Increased.
c. Increased; Decreased
b. Decreased; Increased
d. Decreased; Decreased
Use the provided age structure diagram to answer questions 24 & 25
24. The age structure diagram represents
a. A developed country
b. A developing country
c. A country before the agricultural revolution.
d. A city with high birth rates.
25. If reproduction patterns remain similar over the next 50 years, this
population will likely
a.
Rapidly grow.
b.
Grow slowly.
c.
Gradually shrink in size.
d.
Disappear.
26. Developed countries ________________________________.
a. are highly industrialized
c. have low average incomes
b. make up 80% of the world’s population
d. use about one-fourth of the world’s energy resources
Use the diagram to answer questions 27 – 29
27. Which statement best describes a country in the second stage of the demographic transition?
a. A strong economy with lots of industry.
b. Death rates are much higher than birth rates.
c. Medicine has allowed death rates to decrease but
birth rates are still high
d. Small families with many women in the
workforce.
28. A country in the third stage of the demographic
transition will have what type of population growth:
a. Rapid
b. Slow
c. Zero
29. Countries in the first stage of demographic transition have birth rates that
a.
Are almost equal to the death rates.
c. Are low.
b.
Are higher than death rates.
d. Are causing the population to decrease.
30. Compared to developing nations, developed nations have
a.
less access to birth control
c. faster-growing populations
b.
low literacy levels
d. higher health standards and sanitation
II.
SHORT ANSWER: Answer ONE question in each of the 3 sections (A-C) below. You should have a total of
THREE answers. Use the essay portion of your scantron. The answer to #12 is b.
SECTION A: Ecosystem Dynamics (4pts)
Answer ONE of the following questions:
31. The return of an increasingly diverse ecosystem following a disturbance is known as succession. Following a nuclear
disaster, detail the components of an ecosystem 1 year, 10 years, and 100 years after this massive disturbance where
humans have been banned from returning to the area. A complete answer will use the terms pioneer species and
climax community.
If soil were not present the first organisms to repopulate the area would be pioneer species like moss or lichen. If
soils were present (secondary succession would occur) and pioneer species would be grasses and weeds. After the
ground surface was covered by weeds and grass then small shrub species (mid-succesional) and woody plants would
start to grow. Next there could be small trees and eventually larger trees (hardwoods – oak, maple, hickory), that
would result in a climax community.
32. What is the least important component of a food web? Why? (Be sure to DESCRIBE the necessity of all other
trophic levels for a thorough answer.)
The least important component of the food web would be the quaternary (4th) level consumers. These organisms are
apex predators that although they keep some populations in check do not form the basis for the food web, like
producers (plants that use energy from the sun to make sugars) and also do not keep rapidly reproducing species like
rodent populations in check. Decomposers are important because without them organic matter like plant debris,
organic matter and animal waste would build up in the ecosystem.
Section A continued on next page
33. The number of hunting permits has been doubled in a certain township in an effort to maintain the population of deer
at K. EXPLAIN when this is a good decision. SKETCH a population growth curve to show what the population
must look like to support your explanation. (Hint: Explain the lesson from the Oh Deer simulation. In order to receive
full credit, use the words limiting factor, carrying capacity, resources, in your answer.)
K = carrying capacity. The population would have to mimic a “J” shaped curve, showing exponential growth. If
that’s the case than the deer population is growing too rapidly and will eventually crash, due to road kills, lack of
food, habitat/space and/or starvation. The best population number for deer is the number closest to the carrying
capacity, this level puts less stress on the ecosystem, because the ecosystem can provide resources which match the
number of deer at capacity. If the deer population exceeds carrying capacity then there won’t be enough resources
and some of the deer should be removed (culled).
SECTION B: Adaptations (4pts)
Answer ONE of the following questions:
34. Stink bugs are insects that use a form of chemical defense against predators. During the early stages of an attack, they
release secretions with a very strong odor that affect sensitive areas of the predator’s face and mouth. As a result, the
predator flees before the stinkbug is injured. Explain how stinkbugs might have evolved this specialized defense
mechanism. Include the ideas of natural selection and adaptations in your answer.
35. Use the following information to answer this question:
Tim, a scientist studying guppies in Ecuador, found that the fish had a wide variety of color patterns. A previous study
showed evidence that guppies use color to hide from predators. The following data was collected after capturing guppies
in two habitats in the same stream. He noted the environment, and also any noticeable predators the guppies had.
The differences in guppy coloration at two locations within the
Stream suggest that each population is surviving at a different rate.
In other words, red (mid section – 6 red, 3 blue spots) increases survival in
one area, and blue (lower section – 9 blue, 1 red spots) in another area.
The causes for different colors in different parts of the stream are
Probably related to camouflage patterns that blend in best with the guppy
Habitat (stream bottom, surrounding vegetation, vegetation in the stream).
EXPLAIN why the average
numbers of colored of spots were
different in the mid-stream and
lower-stream pools.
In your description be sure to:
 Describe the differences
between the numbers of
colored spots in the two pools
 Explain the possible causes of
these differences in numbers
of spots
 Include data from the graph to
support your answer.
Number of Colored Spots in Two Stream
Habitats
10
8
Average
Number
of Spots
6
Blue
Red
4
2
0
Mid-Stream
LowerStream
Color of Spots
36. Examine the graph to the right.
Each line represents a different species.
STATE the species interaction that may be occurring
between species A and B and EXPLAIN your reasoning.
Then provide an EXAMPLE of this interaction in an
ecosystem.
Population
SECTION C: Niches/species (4pts)
Answer ONE of the following questions:
120
100
80
60
40
20
0
Species A
Species B
Species C
1
3
5
7
9
Time
The species interaction that is occurring is probably
predator prey because each population level follows the
opposite pattern. When A begins to fall because of being eaten, species B starts to rise because they have more food, but
when species B begins to fall, then species A population recovers and starts to rise. An example would be moose and
wolf populations.
37. The cardon and organ-pipe are flowering cactuses that depend on bats for pollination. The bats pollinate the cacti as
they eat the fruit of the cactuses. Studies of the bats and cacti suggest that local villagers are driving bats living near
these cacti from their cave homes.
 What is the relationship between the bats and the cacti?
 DISCUSS the effects on both populations (bats and cacti) if the number of bats decreases.
The relationship between the bats and cacti is mutualism because both species benefit. If bat numbers decrease, then it is
likely that the cacti, could also decrease because the plants will have to rely on other less effective pollinators or will not
be pollinated at the same rate they once were. Pollination is essential to the plant’s reproduction, so the population of
cacti could go down.