Free Printable Biology Semester 1 Exam 2025

1.

Which of the following would be considered part of an ecosystem?

a)

water

b)

plants

c)

climate

d)

all of these

2.

A biologist observing the reproduction rate of all the deer living in an area would be studying at which level of ecological organization?

a)

Organism

b)

Community

c)

Population

d)

Ecosystem

3.

Energy flows through an ecosystem from the sun to

a)

producers, then consumers

b)

primary consumers

c)

consumers, then producers

d)

secondary consumers

4.

Which of the organisms is (are) producers?

a)

plant

b)

grasshopper

c)

mouse and snake

d)

grasshopper, mouse, snake

5.

Which organism is in the second trophic level?

a)

plant

b)

grasshopper

c)

mouse

d)

snake

6.

Which organism is the primary consumer?

a)

plant

b)

grasshopper

c)

mouse

d)

Snake

7.

The snake eats the mouse. The hawk eats the snake. This is an example of

a)

commensalism

b)

parasitism

c)

predation

d)

competition

8.

If the population of mice doubles, which of the following will probably happen?

a)

the population of grasshoppers will increase

b)

the population of grasshoppers will decrease

c)

the population of grasshoppers will remain the same

d)

the population of grasshoppers and snakes will increase

9.

What would be the correct order of events if the grasshopper population was reduced due to pesticides?

a)

The mouse and snake populations would increase and the plant population would decrease.

b)

The plant population would increase and the mouse and snake population would decrease.

c)

The plant population would increase and the mouse and snake population would increase.

d)

Mutant grasshoppers would grow out of control and take over the known world thus destroying biodiversity.

10.

The diagram above is known as a

a)

habitat

b)

food chain

c)

food web

d)

food net

11.

The photosynthetic phytoplankton are

a)

producers

b)

consumers

c)

parasites

d)

decomposers

12.

Leopard seals are

a)

producers

b)

omnivores

c)

herbivores

d)

carnivores

13.

Which of the following is a tertiary consumer?

a)

phytoplankton

b)

krill

c)

elephant seal

d)

zooplankton

14.

How many communities are shown in the diagram above?

a)

1

b)

4

c)

13

d)

0

15.

Which trophic level would have the largest population size?

a)

A

b)

B

c)

C

d)

D

16.

Level "B" is made up of

a)

carnivores

b)

omnivores

c)

producers

d)

herbivores

17.

How much energy is available to organisms at level "C"

a)

all of the energy at level "A" plus the energy at level "B"

b)

all of the energy at level "A" minus the energy at level "B"

c)

10 percent of the energy at level "B"

d)

90 percent of the energy at level "B"

18.

During which of the following years was the rabbit population at its largest size?

a)

Year 5

b)

Year 12

c)

Year 32

d)

Year 3

19.

How many wolves were present in year 5?

a)

1000

b)

500

c)

3000

d)

4.5

20.

According to this graph, how do the changes in the population of the rabbit affect the changes in the population of the wolves?

a)

When the rabbit population increases, the wolf population increases in the following years.

b)

When the rabbit population increases, the wolf population decreases in the following years.

c)

The rabbit and wolf population sizes are independent (unrelated to) of each other.

d)

When the rabbit population decreases, the wolf population increases in the following years.

21.

The leveling off the population shown in the graph means

a)

A population of seals can never rise above 10,000

b)

After 1945 days no seals were born or died

c)

There were only enough resources in this habitat to support 10,000 male fur seals

d)

After 1940, the population of seals did not go below 10,000

22.

Use the graph on the right to answer the following questions. The point at which the population growth levels off is called the

a)

carrying capacity

b)

maxing capacity

c)

exponential growth

d)

limiting factor

23.

Use the graph on the right to answer the following questions. A hurricane washes away the habitat of the fur seals. The hurricane is a limiting factor that is

a)

a. biotic; density dependent

b)

b. abiotic; density independent

c)

c. biotic; density independent

d)

d. abiotic; density dependent

24.

A bacterial infection causes many of the fur seals to die. The bacterial infection is a limiting factor that is

a)

biotic; density dependent

b)

abiotic; density independent

c)

biotic; density independent

d)

abiotic; density dependent

25.

What structure do all cells have that controls what enters and leaves the cell?

a)

Cell wall

b)

Cell membrane

c)

Nucleus

d)

Ribosomes

26.

What organelle is responsible for energy production in eukaryotic cells?

a)

Nucleus

b)

Membrane

c)

Mitochondria

d)

ribosome

27.

Where is the DNA found in an Eukaryotic cell?

a)

Cell Membrane

b)

Mitochondria

c)

Nucleus

d)

Chloroplast

28.

Which organelle gives plant cells their green color?

a)

Mitochondria

b)

Chloroplast

c)

Cell Membrane

d)

Cell Wall

29.

Which organelle gives plant cells their structure?

a)

Cell Wall

b)

Cell membrane

c)

Chloroplast

d)

Mitochondria

30.

Which student identified a bacteria cell?

a)

Student 1

b)

Student 2

c)

Student 3

d)

None of them

31.

Which student identified a plant cell?

a)

Student 1

b)

Student 2

c)

Student 3

d)

None of them

32.

Which student identified an animal cell?

a)

Student 1

b)

Student 2

c)

Student 3

d)

None of them

33.

The most basic unit of life:

a)

Tissues

b)

Cells

c)

Organs

d)

Organ Systems

34.

Groups of similar cells that work together to perform a specific function:

a)

Tissues

b)

Cells

c)

Organs

d)

Organ Systems

35.

Different types of tissues working together to carry out a particular job:

a)

Tissues

b)

Cells

c)

Organs

d)

Organ Systems

36.

Which of the following shows the correct order from smallest to largest level of organization?

a)

Organ system → Organ → Tissue → Cell → Organism

b)

Cell → Tissue → Organ → Organ system → Organism

c)

Organism → Organ system → Organ → Tissue → Cell

d)

Tissue → Cell → Organ → Organ system → Organism

37.

The lungs work together with the trachea, diaphragm, and other structures to bring oxygen into the body. This is an example of a(n):

a)

Tissue

b)

Organ

c)

Cells

d)

Organ System

38.

Autotrophs are organisms that

a)

produce food using sunlight

b)

survive without energy

c)

do not need cellular respiration

d)

consume other organisms for energy

39.

Heterotrophs are organisms that

a)

produce food using sunlight

b)

survive without energy

c)

do not need cellular respiration

d)

consume other organisms for energy

40.

Photosynthesis and cellular respiration form a cycle of matter because:

a)

the products of one process are the starting material (reactants) for the other

b)

oxygen, the product of cellular respiration, is the starting material for photosynthesis

c)

carbon dioxide, the product of photosynthesis, is the starting material for cellular respiration

d)

both photosynthesis and cellular respiration use the same starting materials

41.

What is the goal of photosynthesis?

a)

to transform the chemical energy of glucose to the energy of ATP

b)

to transform the energy of ATP to the light energy of the sun

c)

to transform the light energy of the sun to the energy of ATP

d)

to transform the light energy of the sun to the chemical energy of glucose

42.

Photosynthesis requires each of the following EXCEPT

a)

light

b)

carbon dioxide

c)

water

d)

oxygen

43.

The organelle where photosynthesis takes place is the

a)

mitochondria

b)

nucleus

c)

stomata

d)

chloroplasts

44.

What is the pigment responsible for absorbing the light energy for photosynthesis?

a)

chloroplast

b)

chlorophyll

c)

catalyst

d)

chloroform

45.

What wavelength of light is absorbed the most for photosynthesis?

a)

410 nm

b)

430 nm

c)

500 nm

d)

660 nm

46.

Leaves appear green because

a)

blue light is mostly absorbed by chlorophyll

b)

green light is mostly absorbed by chlorophyll

c)

red light is mostly absorbed by chlorophyll

d)

green light is mostly reflected by chlorophyll

47.

A student measured the growth of peanut plants under four different colors of light. The plants were provided the same amount of fertilizer, water and time under the lamps. Light Color | Growth of Peanut Plants (cm) A | 66 B | 58 C | 9 D | 60 49. What is the independent variable in this experiment?

a)

light color

b)

plant growth

c)

type of plant

d)

amount of time

48.

What is the dependent variable in this experiment?

a)

light color

b)

plant growth

c)

type of plant

d)

amount of time

49.

Which of the following is NOT a constant in this experiment?

a)

plant growth

b)

amount of water

c)

type of plant grown

d)

amount of time

50.

Based on the student's data, which light color is most likely blue?

a)

A

b)

B

c)

C

d)

D

51.

Based on the student's data, which light color is most likely green?

a)

A

b)

B

c)

C

d)

D

52.

Which of the following is an acceptable justification for the data above?

a)

green light is highly absorbed and therefore produces a high rate of photosynthesis and plant growth

b)

green light is highly reflected and therefore produces a high rate of photosynthesis and plant growth

c)

green light is highly absorbed and therefore produces a low rate of photosynthesis and plant growth

d)

green light is highly reflected and therefore produces a low rate of photosynthesis and plant growth

53.

The graphs below show the effect of light (1) and the effect of temperature (2) on the rate of photosynthesis. Graph 1 shows that the rate of photosynthesis:

a)

decreased in response to increasing light intensity

b)

increases in response to increasing light intensity

c)

increases in response to decreasing light intensity

d)

is unaffected by changes in light intensity

54.

Graph 2 shows that the temperature with the highest rate of photosynthesis is

a)

45°C

b)

5°C

c)

20°C

d)

30°C

55.

What types of organisms must carry out cellular respiration for survival?

a)

animals only

b)

all organisms except autotrophs

c)

all heterotrophs

d)

all living organisms

56.

Cellular respiration is an important process because it creates ______, the only form of energy the cell can use.

a)

ATP

b)

sugar

c)

DNA

d)

Fat

57.

The organelle where cellular respiration takes place is the

a)

mitochondria

b)

nucleus

c)

stomata

d)

chloroplasts

58.

A group of students designed an investigation to find out which type of sugar was best for cellular respiration. They tested a monosaccharide, a disaccharide, and a polysaccharide. The students mixed 1 mL of yeast with 1 mL of sugar solution. They used a gas sensor to measure the amount of gas given off over 10 minutes and calculated the rate of respiration. Their data is shown in the graph shown. What is the independent variable for this experiment?

a)

time

b)

respiration rate

c)

type of sugar

d)

amount of yeast

59.

What is the dependent variable in this experiment?

a)

time

b)

respiration rate

c)

type of sugar

d)

amount of yeast

60.

The rate of cellular respiration was calculated by measuring the amount of gas given off by the yeast in 10 minutes. What was that gas?

a)

Oxygen because it is a product of cellular respiration

b)

Carbon dioxide because it is a product of cellular respiration

c)

Oxygen because it is used in cellular respiration

d)

Carbon dioxide because it is used in cellular respiration

61.

Which of the following is true about sugar molecules?

a)

Carbohydrates bond together to make sugars.

b)

Monosaccharides are made up of many polysaccharide molecules.

c)

Two monosaccharides bond together to make a disaccharide.

d)

Polysaccharides consist of two disaccharide molecules.

62.

Which of the following is the most appropriate claim for the guiding question in this experiment?

a)

Monosaccharides produced the most gas during cellular respiration.

b)

Disaccharides are the largest sugars.

c)

Glucose is used in cellular respiration.

d)

Disaccharides produced the highest rate of cellular respiration in yeast.

63.

Which of the following best explains the results of this experiment?

a)

The polysaccharide had the lowest rate of respiration because it takes too long to break down.

b)

The disaccharide provides more sugar molecules than the monosaccharide and therefore produces a higher rate of cellular respiration.

c)

All sugars are used equally in cellular respiration.

d)

Statements A and B are both true.

64.

The yeast in the experiment are performing anaerobic respiration. Anaerobic respiration differs from aerobic cellular respiration in that

a)

requires oxygen

b)

produces more ATP

c)

does not require oxygen

d)

happens only in animals

65.

What is the name of the process labeled A that moves carbon to the soil?

a)

Cellular respiration

b)

Combustion

c)

Photosynthesis

d)

Decomposition

66.

What process moves carbon (CO2) from the atmosphere into living things?

a)

Cellular respiration

b)

Combustion

c)

Photosynthesis

d)

Decomposition

67.

The diagram traces the flow of energy in an ecosystem. Each ARROW refers to a PROCESS that occurs. Each BOX refers to a FORM OF ENERGY. Match the terms to their correct position in the diagram above.

a)

ATP

1.

D

b)

Cellular respiration

2.

C

c)

Glucose

3.

B

d)

Photosynthesis

4.

A

68.

What kind of organisms perform process A?

a)

autotrophs

b)

heterotrophs

c)

decomposers

d)

all organisms

69.

What kind of organisms perform process C?

a)

autotrophs

b)

heterotrophs

c)

decomposers

d)

all organisms

70.

Homeostasis in the human body can best be described as:

a)

The body's attempt to maintain a constant or stable internal environment.

b)

A constant state of being maintained by living and nonliving organisms.

c)

Bodily adaptations evolved over time to changes in the external environment.

d)

Processes that occur as a result of diseases and trauma.

71.

How does your body maintain a constant temperature when it is cold outside?

a)

The kidneys and bladder remove excess water from the body

b)

The muscles start shaking

c)

Skin cells sweat to evaporate water from the body

d)

The liver releases more sugar into the bloodstream

72.

How does your body maintain a constant water level when you drink too much water?

a)

The kidneys and bladder remove excess water from the body

b)

The muscles start shaking

c)

Skin cells sweat to evaporate water from the body

d)

The liver releases more sugar into the bloodstream

73.

Which graph correctly shows how your body maintains normal blood sugar levels?

a)

A

b)

B

c)

C

74.

What structure is illustrated on the right?

a)

mitochondria

b)

cell membrane

c)

nucleus

d)

cell wall

75.

The structures labeled B, D, and E are

a)

lipids

b)

carbohydrates

c)

proteins

d)

nucleic acids

76.

The ability of this structure to allow only certain molecules to pass in or out of the cell is known as

a)

facilitated diffusion

b)

selective permeability

c)

osmosis

d)

active transport

77.

In each of these processes, molecules move from

a)

High concentration to low concentration

b)

Hypertonic concentration to a hypotonic concentration

c)

Low concentration to high concentration

d)

Equal concentration to different concentration

78.

Which of the beakers above illustrates equilibrium?

a)

Beaker A

b)

Beaker B

c)

Beaker C

79.

The dye and the water create a solution. The dye is dissolved in the water and represents what part of the solution?

a)

solute

b)

solvent

80.

Which picture shows a cell in a hypertonic solution?

a)

(Red blood cell with water leaving)

b)

(Red blood cell with water entering)

c)

(Red blood cell with no net movement)

81.

Which picture shows a cell in a hypotonic solution?

a)

(Red blood cell with water leaving)

b)

(Red blood cell with water entering)

c)

(Red blood cell with no net movement)

82.

Which picture shows a cell in an isotonic solution?

a)

A. (Red blood cell with water leaving)

b)

B. (Red blood cell with water entering)

c)

C. (Red blood cell with no net movement)

83.

A student filled model cells made of dialysis tubing with 10 mL of distilled water and placed them in 100 mL of alcohol solutions with increasing concentrations of alcohol. Alcohol is a solute and the model cell is impermeable to the alcohol. The student weighed the model cells, soaked them in the alcohol solutions for 24 hours, and weighed the cells again. She recorded her data in the table below. What is the independent variable of this experiment?

a)

alcohol concentration

b)

amount of time

c)

dialysis tubing

d)

water content

84.

A student filled model cells made of dialysis tubing with 10 mL of distilled water and placed them in 100 mL of alcohol solutions with increasing concentrations of alcohol. Alcohol is a solute and the model cell is impermeable to the alcohol. The student weighed the model cells, soaked them in the alcohol solutions for 24 hours, and weighed the cells again. She recorded her data in the table below. What is the control trial in this experiment?

a)

water content of cells

b)

the 0% alcohol solution

c)

time

d)

10 mL of water in each cell

85.

A student filled model cells made of dialysis tubing with 10 mL of distilled water and placed them in 100 mL of alcohol solutions with increasing concentrations of alcohol. Alcohol is a solute and the model cell is impermeable to the alcohol. The student weighed the model cells, soaked them in the alcohol solutions for 24 hours, and weighed the cells again. She recorded her data in the table below. Which of the following is a true statement?

a)

The mass of the cell changed because alcohol moved into the bag

b)

The mass of the cell changed because alcohol moved out of the bag

c)

The mass of the cell changed because water moved into the bag

d)

The mass of the cell changed because water moved out of the bag

86.

A student filled model cells made of dialysis tubing with 10 mL of distilled water and placed them in 100 mL of alcohol solutions with increasing concentrations of alcohol. Alcohol is a solute and the model cell is impermeable to the alcohol. The student weighed the model cells, soaked them in the alcohol solutions for 24 hours, and weighed the cells again. She recorded her data in the table below. Which of the following would be the most appropriate claim based on this experiment?

a)

As the concentration of alcohol increases, the water content of a cell decreases.

b)

As the concentration of alcohol increases, the water content of a cell increases.

c)

As the weight of the cell decreases, the alcohol concentration increases.

d)

As the weight of the cell decreases, the alcohol concentration decreases.

87.

The diffusion of water is called

a)

active transport

b)

osmosis

c)

facilitated diffusion

d)

protein pump

88.

Which of the following correctly explains why this occurred?

a)

The concentration of water was higher inside the bag than outside the bag.

b)

The concentration of water was lower inside the bag than outside the bag.

c)

The concentration of alcohol was higher inside the bag than outside the bag.

d)

The concentration of water and alcohol was equal inside and outside the bag.

Biology Semester 1 Exam 2025 - Unit 1: Ecology

Total questions: 88

Worksheet time: 44mins

Similar Resources on Wayground