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CAST Science Practice Test

Total questions: 114

Worksheet time: 57mins

Name
Class
Date
1.

Use the graphs and the partial food web to predict the changes in the sea urchin population as the kelp pupulation INCREASES. What will happen to the sea urchin population?

a)

Sea urchin population increases

b)

Sea urchin population decreases

c)

Sea urchin population remains steady

2.

Use the graphs and the partial food web to predict the changes in the kelp population as the kelp pupulation INCREASES. What will happen to the kelp population?

a)

Kelp population increases

b)

Kelp population decreases

c)

Kelp population remains steady

3.

A student conducts 5 trials to investigate factors affecting the formation of impact craters. The student drops a marble into a box with fine powder. Analyze the results in the graph pictured. Because the mass is 40g in each trial, mass is a...

a)

constant

b)

control

c)

dependent variable

d)

independent variable

4.

A student conducts 5 trials to investigate factors affecting the formation of impact craters. The student drops a marble into a box with fine powder to measure the depth. Analyze the results in the graph pictured. Depth is the

a)

constant

b)

control

c)

dependent variable

d)

independent variable

5.

A student conducts 5 trials to investigate factors affecting the formation of impact craters. The student drops a marble into a box with fine powder at different speeds to measure the depth. Analyze the results in the graph pictured. Speed is the

a)

constant

b)

control

c)

dependent variable

d)

independent variable

6.

A student conducts 5 trials to investigate factors affecting the formation of impact craters and here are the results. What is true about the results of the experiment?

a)

As the speed of the marble increases, the depth of the crater increases

b)

As the speed of the marble increases, the depth of the crater decreases

c)

As the speed of the marble increases, the depth of the crater stays the same

7.

A student conducts 5 trials to investigate factors affecting the formation of impact craters and here are the results. Which statement BEST describes the results of the investigation?

a)

The kinetic energy of the marble just before impact is proportional to the depth of the crater it forms

b)

The kinetic energy of the marble just before impact is proportional to the mass of the marble

c)

The depth of the crater is proportional to the mass of the marble

d)

The depth of the crater is proportional to the mass of the marble

8.

Read the question in the photo. Select a moon location in the model that supports the explanation that the New Moon phase explains why the disk becomes a ring.

a)

1

b)

2

c)

3

d)

4

9.

A student reviews the model shown and says that, based on the model, a solar eclipse should happen every time there is a new moon. However, solar eclipses occur less often than New Moons. Which feature of the model should be revised to best explain why solar eclipses do not happen every month?

a)

The model should show that the shape of the Earth's orbit around the Sun is an ellipse.

b)

The model should show that the shape of the Moon's orbit around the Earth is an ellipse.

c)

The model should show that Earth's equator is inclined relative to the plane of Earth's orbit around the Sun.

d)

The model should show that the plane of the Moon's orbit around the Earth is inclined relative to the plane of Earth's orbit around the Sun.

10.

Leah is learning to use properties of substances to identify a chemical reaction. She conducts two trials. In the first trial, she pours silicon dioxide (SiO2) into water (H2O). For the second trial, she pours silver nitrate (AgNO3) solution into a test tube with a solution of potassium chloride (KCl). Look at the diagram. In which trial did a chemical reaction occur?

a)

Trial 1

b)

Trial 2

c)

Both trial 1 and trial 2

d)

No chemical reaction happened in either

11.

Leah is learning to use properties of substances to identify a chemical reaction. She conducts two trials. In the first trial, she pours silicon dioxide (SiO2) into water (H2O). For the second trial, she pours silver nitrate (AgNO3) solution into a test tube with a solution of potassium chloride (KCl). Look at the diagram. Leah knows a chemical reaction occurred in Trial 2 because

a)

a substance with a new properties was made (new white solid)

b)

the same substances remained

12.

Leah records properties of the substances she mixed before and after the trials. Which property or properties show that a chemical reaction occurred?

a)

State of matter ONLY

b)

Mass

c)

Color ONLY

d)

Both state of matter and color

13.

Leah made a model of the reaction between Iron and Copper Sulfate. However, it needs improvements. Which statement best describes which improvements need to be made?

a)

The mass of the reactants does not equal the mass of the products.

b)

The number of atoms for the reactants is different than the products

c)

The number of atoms for the reactants is the same as the products

d)

The composition of atoms for the reactants is different than the products

14.

Which model shows a balanced chemical reaction?

a)
b)
c)
15.

According to this model, Fe, or Iron, is represented by

a)
b)
c)
d)
16.

According to this model, what are the products made from the chemical reaction?

a)

Fe

b)

CuSO4

c)

Cu

d)

FeSO4

17.

How many atoms make up CuSO4 ?

a)

1

b)

4

c)

5

d)

6

18.

According to this "Key" that models atoms and molecules, the molecules are

a)

Fe and CuSO4

b)

FeSO4 and CuSO4

c)

Fe and Cu

d)

Cu and CuSO4

19.

Leah combined Fe and CuSO4 and measured the masses before and after a reaction. What is the total mass of the reactants?

a)

96 grams

b)

25 grams

c)

71 grams

d)

192 grams

20.

Leah combined Fe and CuSO4 and measured the masses before and after a reaction. What is TRUE about the total mass of the reactants and the total mass of the products?

a)

They are the same (96 grams)

b)

They are different

21.

Leah conducts an investigation by mixing Fe with CuSO4 and makes a model to help explain why the total mass did not change. Leah's model can also be used to show that a chemical reaction occurred because the products

a)

are the same size as the reactants

b)

have the same composition as the reactants

c)

are at different states of matter compared to the reactants

d)

have differently arranged atoms compared to the reactants

22.

Which model correctly shows that the mass is conserved in the reaction? 

a)
b)
c)
d)
23.

Which model correctly shows that the mass is conserved in the reaction? 

a)
b)
c)
d)
24.

In this equation, the reactants are on the

a)

left of the arrow

b)

right of the arrow

25.

In this equation, the products are on the

a)

left of the arrow

b)

right of the arrow

26.

Because this model shows atoms connected by a chemical bond, you are looking at

a)

atoms

b)

single elements

c)

molecules or compounds

27.

After the predator is introduced, which fish has a BETTER chance of surviving?

a)

light colored fish

b)

dark colored fish

c)

both light and dark have the same chance of surviving

28.

Why would the dark colored fish have a better chance of surviving after the new predator is introduced?

a)

The predator can move faster than this species of small fish

b)

The predator cannot see them as well as the fish of the light color

c)

The predator predicts where each fish will be

29.

Students are asked to make a claim about which design will be both break-resistant and keep the water hot for the longest time. Which claim best meets the two criteria?

a)

Bottle 1: It has an unbreakable steel lining.

b)

Bottle 2: It has a glass inner lining which is a better insulator

c)

Bottle 3: It has an unbreakable steel inner lining and a foam cover that will keep the water hot for the longest time.

d)

Bottle 3: It has glass inner lining and a foam cover that will keep the water hot for the longest time.

30.

Choose a claim that best agrees with the data.

a)

Mass does not affect the gravitational force between two objects

b)

Mass is the only variable that affects the gravitational force between two objects

c)

Distance is the only variable that affects the gravitational force between two objects

d)

Both mass and distance are variables that affect the gravitational force between two objects.

31.

MATH REVIEW (EXPONENTS): Which is bigger?

a)

2.6 x 10-9

b)

6.5 x 10-10

c)

1.0 x 10-8

32.

This graph shows almond production in the US since 2012. What is true about the graph?

a)

Almond production has increased from 2014-2017

b)

Almond production has decreased from 2014-2017

c)

Almond production has stayed the same from 2014-2017

33.

Read the image description. What point in the graph represents rapid growth?

a)

A

b)

B

c)

Neither A nor B

34.

Read the image description. What point in the graph represents the paramecium reaching carrying capacity?

a)

A

b)

B

c)

Neither A nor B

35.

Based on this information, which earthquake has the GREATEST likelihood of causing a tsunami to develop?

a)

Earthquake A

b)

Earthquake B

c)

Earthquake C

d)

Earthquake D

36.

A student wants to show a friend that a magnetic field exists in the region around a permanent magnet. Which demonstration shows that a field exists?

a)

A magnet touches a paper clip and picks it up from the table

b)

A magnet is held near a small metal ball, making it roll across the table

37.

A student wants to show a friend that a magnetic field exists in the region around a permanent magnet. Which demonstration shows that a field exists?

a)

The north pole of a magnet sticks to the south pole of the second magnet when they touch

b)

A small magnet held under a piece of paper with iron filings on top makes the filings move into a pattern that covers the whole piece of paper

38.

What TWO things are true about PLANTS?

a)

Produce CO2 that is used in photosynthesis

b)

Use CO2 in photosynthesis

c)

Produce O2 that is used in cell respiration

d)

Use O2 in cell respiration

39.

What TWO things are true about ANIMALS?

a)

Produce CO2 that is used in photosynthesis

b)

Use CO2 in photosynthesis

c)

Produce O2 that is used in cell respiration

d)

Use O2 in cell respiration

40.

The student proposes to test the claim in the lab by using metal rods made of Iron, Copper, and Aluminum. In addition to metal rods, which pieces of equipment would be useful for investigating their claim?

a)

prism, heat lamp, screen, meterstick

b)

beaker, digital scale, stopwatch, clamps

c)

litmus paper, beaker, pan balance, battery

d)

hot water, pan to hold water, stopwatch, thermometer

41.

Which statement describes the most likely impact of the mutation in the mutated sequence?

a)

There will be no effect because the rest of the DNA is normal

b)

The extra nucleotide will be deleted before the protein is formed

c)

The protein formed will not be the same as that formed from the original DNA

d)

The mutated DNA will code for the same number of amino acids as the original sequence

42.

Students want to determine what effect the eruption had on global climate. Which question should the students investigate to BEST determine the effect?

a)

What was the temperature of the laba that flowed onto Earth's surface when Mount Pinatubo erupted?

b)

Was the amount of rain that fell on Mount Punatubo in the days after the eruption greater or less than average?

c)

Do aerosol particles of this type cause the amount of solar energy that reaches the Earth's surface to increase or decrease?

43.

According to the graph, what evidence is true about the rate of photosynthesis during a La Nina event?

a)

During a La Nina event, the light intensity is reduced (as more clouds block sunlight), therefore reducing CO2 uptake and slowing down the rate of photosynthesis.

b)

During a La Nina event, the light intensity is increased, therefore increasing CO2 uptake and increasing the rate of photosynthesis.

c)

During a La Nina event, the light intensity stays the same, therefore reducing CO2 uptake and not changing the rate of photosynthesis.

44.

Which evidence could be used to CHALLENGE a biologist's claim that purple flowers attract more pollinators than other flower colors do?

a)

The purple flowers did not have any butterfly or beetle pollinators

b)

Bees pollinated the purple flowers 12 times and white flowers only 1 time

c)

The purple flowers were pollinated 17 times, the white flowers 3 times, and pink flowers 2 times.

45.

Which wave characteristics (if any) does the energy of a wave depend on?

a)

the amplitude ONLY

b)

the wavelength ONLY

c)

BOTH the amplitude and wavelength

d)

NEITHER the amplitude and wavelength

46.

Adding garden lime REDUCES acidity of the soil. Based on the data, if someone adds lime juice to neutral soil over time, what will happen to the acidity of the soil?

a)

it becomes more basic

b)

it becomes more acidic

c)

it stays neutral

47.

Adding garden lime REDUCES acidity of the soil. Based on the data, if someone adds lime juice to neutral soil over time, what color will hydrangea flowers become?

a)

blue

b)

purple

c)

pink

48.

What statement is most likely correct?

a)

Layer C is below Layer B, so Layer C is older

b)

Layer D is younger than Layer C

c)

Layer A is the oldest layer

49.

What statement is most likely correct?

a)

There is no coral fossil in Layer D, so it went completely extinct

b)

Layer D is younger than Layer C

c)

Layer A is the youngest layer because it is at the top

50.

What statement is most likely correct?

a)

There is no coral fossil in Layer D, so it went completely extinct

b)

The gastropod fossils are above the crinoid fossil so they for sure evolved from crinoids

c)

The ammonite fossil is above the crinoid fossil, so the crinoid fossil is older

51.

Which best explains why the embyos are similar in appearance, yet the adults look different?

a)

Pigs and chickens are in the same genus

b)

All vertebrate embryos have the same DNA

c)

As the embryos grow, they undergo mutations

d)

Some developmental processes are shared by vertebrates

52.

According to the data table, which type of plastic can help conserve natural resources?

a)

Plastic A

b)

Plastic B

c)

Neither Plastic A or Plastic B

53.

Based on this data, what statement is most likely correct?

a)

The height of the plants is most directly controlled by genetic factors

b)

The height of the plants is most directly controlled by environmental factors

54.

Based on this data, what statement is most likely correct?

a)

Near sea level, the taller plants are better able to survive and reproduce than the shorter plants

b)

At higher elevations, the taller plants are better able to survive and reproduce than the shorter plants

55.

Which model correctly represents the correct number of CO2 and H2O molecules produced if mass is conserved?

a)
b)
c)
d)
56.

Based on the model, what should the student say about the role of living organisms in the water cycle?

a)

Plants help move water from the soil to the atmosphere

b)

Animals generate heat that helps evaporate water from the land

c)

Plant movements create wind that helps draw water into the atmosphere

d)

Animals create pathways in the mountains that allow water to flow downhill

57.

Why might introducing a new fish be a bigger problem than the invasive plant species?

a)

The fish might cause a decrease in the number of native, beneficial plants

b)

The fish might cause an increase in the number of native, beneficial plants

c)

The fish might attract fisherman to the lake

58.

According to the data table, which TWO methods require an external source of energy?

a)

filtration system

b)

chemical disinfectant tablets

c)

Ultraviolet Light

d)

Boiling

59.

Water in lakes and streams may contain particles of soil and decaying plants that cloud the water. Which method will MOST LIKELY be effective at making the water clear when removing pathogens?

a)

filtration system

b)

chemical disinfectant tablets

c)

Ultraviolet Light

d)

Boiling

60.

Which set of forces will allow the students to demonstrate all three cases of motion?

a)
b)
c)
d)
61.

One type of conservation practice is irrigating crops with treated wastewater. Doing this MOST DIRECTLY conserves groundwater by

a)

reducing water waste

b)

reusing water

c)

providing another source of water

62.

One type of conservation practice is using indoor faucet nozzles that limit water flow. Doing this MOST DIRECTLY conserves groundwater by

a)

reducing water waste

b)

reusing water

c)

providing another source of water

63.

One type of conservation practice is using water from a rainwater collection system. Doing this MOST DIRECTLY conserves groundwater by

a)

reducing water waste

b)

reusing water

c)

providing another source of water

64.

Students are designing a solar oven that can be made from materials found in their homes. Solar ovens take more time to heat food than regular ovens. The students would like to build a solar oven that heats food as quickly as possible. What TWO things should they consider?

a)

type of food that will be heated

b)

how often the oven will be used to heat food

c)

possible ways of preventing or reducing heat loss from the oven

d)

designing an oven that will collect as much sunlight and absorb as much heat as possible

65.

Students are designing a solar oven that can be made from materials found in their homes. Solar ovens take more time to heat food than regular ovens. The students would like to build a solar oven that heats food as quickly as possible. What would IMPROVE the rate of heating?

a)

Covering the interior walls of the oven with a reflective material like aluminum foil

b)

allowing outside air to circulate inside the oven

c)

using cookware that is uncovered and open to the atmosphere

66.

Which statement BEST describes how the model represents the Sun and Earth?

a)

The ball is the Sun, the pole is the force of gravity, and the rope is the Earth

b)

The ball is the Sun, the pole is the Earth, and the rope is the force of gravity

c)

The ball is the Earth, the pole is the Sun, and the rope is the force of gravity

d)

The ball is the Earth, the pole is the force of gravity, and the rope is the Sun

67.

Students observed plants in the field and took pictures over the course of 3 years. The observations show that

a)

Anderson's thistle population decreases while the Canada thistle population increases

b)

Anderson's thistle population increases while the Canada thistle population decreases

c)

Anderson's thistle population decreases while the Canada thistle population stays the same

68.

Students observed plants in the field and took pictures over the course of 3 years. Looking at 3 years of observations, the students assume the environmental conditions of the field will stay the same for the next 3 years. What prediction is MOST LIKELY?

a)

The field will only have Canada Thistle

b)

The field will only have Anderson's Thistle

69.

Students are conducting an investigation on the rise in average temperatures in their city over the years. They also observed graphs of global temperature rise. They set up the beakers pictured. What should be true about their investigation?

a)

It should model the interaction between Earth's atmosphere, greenhouse gases, and sunlight

b)

It should model the interaction between Earth's atmosphere, greenhouse gases, and humidity.

c)

It should model the interaction between Earth's atmosphere, greenhouse gases, and landforms.

70.

Students measured the temperature of 3 different beakers to model the interaction between Earth's atmosphere and sunlight. Which claim is true based on the graph?

a)

A change in temperature causes a change in CO2

b)

A change in CO2 will cause a change in temperature

c)

Changes in CO2 are not connected to changes in temperature

71.

What is true about the relative potential energy at various points in the roller coaster diagram?

a)

At "1", the potential energy is greater than the potential energy at "3"

b)

At "3", the potential energy is greater than the potential energy at "4"

c)

At "4", the potential energy is greater than the potential energy at "2"

72.

What is true about the transfer of energy?

a)

From point "2" to "3", the energy stored in the train is transformed into kinetic energy, then into motion, thermal, and sound energy

b)

From point "2" to "3", the energy stored in the train is transformed into potential energy, then into motion, thermal, and sound energy

73.

What is true about the transfer of energy from point "3" to point "4"?

a)

From point "3" to "4", the kinetic energy is transformed back into potential energy

b)

From point "3" to "4", the potential energy is transformed back into kinetic energy

74.

Measurements of the speed of the train show that energy is being lost. Which claim is true if evidence collected shows the tracks are warmer after the train has passed?

a)

The loss of energy is due to the friction of the train wheels to the track

b)

The loss of energy is due to the air pushing back on the train as it moves down the track

75.

What is the independent variable?

a)

atomic number

b)

electron volts

c)

first ionization energy

d)

Jim Askew's Graph

76.

What is the dependent variable?

a)

nicest fruit

b)

number of people

c)

types of fruit

77.

What would most likely be the temperature at 2 1/2 minutes?

a)

58

b)

62

c)

78

d)

88

78.

Crickets chirp to attract other crickets. The temperatures and rates of their chirping are graphed above. Which statement below is most likely true for the data represented in the graph?

a)

A. The cooler the temperature, the louder the crickets chirp.

b)

B. The crickets cannot chirp at temperatures lower than 10 degrees Celcius

c)

C. The warmer the temperature, the more often crickets chirp.

d)

D. The temperature and the chirping of crickets are not related.

79.

According to this graph, which of these is most important in developing the biomass of these plants?

a)

Nitrates

b)

Sulfates

c)

Magnesium

d)

Iron

80.

The line graph shows the heights of plants grown in fertilized and unfertilized soil. Based on this information, what will most likely occur on day six?

a)

Neither plant should increase by 1 cm in height.

b)

Plant A should increase about 1 cm in height.

c)

Plant B should increase about 1 cm in height.

d)

Plant A should increase about 2 cm in height.

81.

The line graph shows five years of data about a dog. What information does the graph show?

a)

A. How the mass of the dog changed

b)

B. How much food the dog consumed

c)

C. What kinds of food the dog consumed

d)

D. When the dog was measured each month

82.

According to this chart, which planet will most likely have the highest temperatures?

a)

Earth

b)

Mars

c)

Mercury

d)

Venus

83.

Students used a computer simulation to determine the variables that affect gravitational force between two object. They collected the data shown in the table. Which claim best agrees with the data?

a)

Mass does not affect the gravitational force between two objects

b)

Mass is the only variable that affects the gravitational force between two objects

c)

Distance is the only variable that affects the gravitational force between two objects

d)

Both mass and distance are variables that affect the gravitational force between to objects

84.

The Goliath roller coaster train is made up of six cars that have a total mass of 3,300 kg when empty. The students attach a sensor to the train that automatically measures the velocity of the train in m/s as the train reaches the bottom of the first hill. The use these data to calculate the kinetic energy of the train in joules (J). The first test is conducted with an empty train. The second test is conducted, with enough students riding to fill three cars. The mass of the students is added to the mass of the empty train. A third test is conducted, with enough students to fill all six cars. Again, the mass of the students is added to the mass of the empty train. The students’ data are shown in the table. What would happen to the calculated kinetic energy of the empty train in the cars were made out of a material that reduced the mass of the empty train to 1,650 kg?

a)

The kinetic energy would increase

b)

The kinetic energy would decrease

85.
The horizontal row on the periodic table is called a
a)
group
b)
family
c)
period
d)
atomic number
86.
A vertical column is called...
a)
group
b)
tower
c)
period
d)
crew
87.
Which of the following is the most metallic element in period 3?
a)
Boron (B)
b)
Sodium (Na)
c)
Argon (Ar)
d)
Silicon (Si)
88.
The number at the bottom of each square on the periodic table is the ...
a)
atomic number
b)
atomic mass
c)
chemical symbol
d)
element name
89.
The number at the top of each square on the periodic table is the ...
a)
atomic number
b)
atomic mass
c)
Chemical Symbol
d)
Element Name
90.
What is the chemical symbol for Lithium?
a)
H
b)
He
c)
Li
d)
N
91.
What is the atomic number of this element?
a)
4
b)
80
c)
79
d)
8
92.
What is the symbol for Potassium?
a)
P
b)
K
c)
Pb
d)
Pd
93.
Is this equation balanced?
a)
yes
b)
no
c)
Not enough information
94.
Is the equation balanced?: 2H2O + O2 --> 4MgO + 3Fe
a)
Yes
b)
No
95.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O--> 2AlO3
a)
2
b)
6
c)
1
d)
4
96.

How many atoms are represented in the reactants in the equation?

a)

6

b)

7

c)

4

d)

5

97.

How many atoms in all are found in the compound above?

a)

3

b)

4

c)

5

d)

6

98.

How many elements are in C6H12O6?

a)

1

b)

2

c)

3

d)

4

99.
If I kick a soccer ball across the field, what vocabulary word tells me why the ball would slow down in the grass?
a)
acceleration
b)
friction
c)
gravity
100.
If a lizard can run 8m across the water in 4 seconds, how fast is he travelling?
a)
32 m/s
b)
2 seconds
c)
2 m/s
d)
34 meters
101.
What will the net force on the soccer ball be?
a)
50 N to the left
b)
50 N to the right
c)
200 N to the left
d)
200 N to the right
102.
What happens when two forces act in the same direction?
a)
They cancel each other out.
b)
The stronger one prevails.
c)
Their strengths are added.
d)
Their sum divided by the two is the total force.
103.

Which graph could represent a car moving at a constant speed in a forward direction?

a)
b)
c)
d)
104.

Which law states that the acceleration of an object depends on the force exerted on it and its mass?

a)

1st Law (Law of Inertia)

b)

2nd Law (Law of Acceleration)

c)

3rd Law (Law of Action-Reaction)

105.

Billy pushes his little brother on a sled through the snow. He then tries to push his father on the the same sled. He noticed that it was much harder to push his father. Which law is this an example of?

a)

1st Law (Law of Inertia)

b)

2nd Law (Law of Acceleration)

c)

3rd Law (Law of Action-Reaction)

106.

a force is best defined as ---

a)

the application of weight

b)

a push or pull that is exerted on matter

c)

the flow of electric charges

d)

a bond in which electrons are shared

107.

To make an object move you must first apply ---

a)

an opposing force

b)

an unbalanced force

c)

a stationary force

d)

a vertical force

108.
What is the net force?
a)
30 N left
b)
25 N right
c)
5 N left
d)
55 N right
109.
Calculate the Net Force. 
a)
40N, Left
b)
40N, Right
c)
0N, Balanced
d)
75N, Right
110.
If an object is not moving the forces acting upon it are _____________
a)
unbalanced
b)
weak
c)
balanced
d)
Hulk Smash!
111.

What is true about this picture?

a)

the forces are balanced

b)

the net force is 10N

c)

The net force is 3 N

d)

The net force is 7N

112.

Peppered moths were able to adapt to their environment because

a)

They decided to change colors in order to survive

b)

The population had varying traits

c)

Pollution covered the trees

d)

The trees camouflaged all moths

113.
A population of peppered moths with a dark grey variation and a light grey variation lives in light colored birch forest. It is hunted by sight. Which statement is most likely true?
a)
there are equal number of light and dark grey peppered moths in the population
b)
more light grey moths survive than dark grey moths
c)
more dark grey moths survive than light grey moths
d)
all peppered moths will be eaten before they can reproduce
114.

A yellow morph and green morph of an insect lives in the rainforest canopy. You would expect:

a)

the green population to increase and the yellow to decrease

b)

both populations should stay the same

c)

both populations will increase

d)

the green population to decrease and the yellow to increaseThis is a wrong answer