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WorksheetsFall 2025 Semester Exam Review
Total questions: 91
Worksheet time: 48mins
Name
Class
Date
1.
What is predation?
a)
act of one organism feeding on another organism
b)
process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere
c)
exchange of matter through the biosphere involving living organisms, chemical pro cesses, and geological processes
d)
process through which nitrogen gas is captured and converted into a form that plants can use
2.
Which is an abiotic factor?
a)
an ocean current of cold water
b)
a polar bear on an ice floe
c)
fungi and moss on a rotting log
d)
a forest of deciduous trees
3.
What does a decrease in salmon population due to an increase in river temperature indicate?
a)
an abiotic factor affecting a biotic factor
b)
an unchanging biological community
c)
change in population but not in abiotic factors
d)
an effect of predation
4.
What is a biological community?
a)
all the interacting populations of a different species that live in the same geographic location at the same time
b)
physical area where an organism lives
c)
a role, or position of an organism in its environment
d)
group of organisms of the same species that occupy the same geographic area at the same time
5.
The suffix -ology comes from the Latin word meaning to study. What is ecology the study of?
a)
he interrelationships between organisms and their environment
b)
how certain organisms are able to use sound to locate objects around them
c)
organic molecules
d)
the interrelationships between single-cell organisms
6.
What is commensalism?
a)
symbiotic relationship in which one organism benefits and the other organism is neither helped nor harmed
b)
symbiotic relationship in which one organism benefits at the expense of another organism
c)
symbiotic relationship in which both organisms benefit
7.
In the nitrogen cycle, nitrogen is continuously recycled. Which type of organisms break down nitrogen compounds in dead organisms and recycle them into the soil?
a)
bacteria
b)
herbivores
c)
autotrophs
d)
green plants
8.
What is released at each level of a pyramid of energy?
a)
heat
b)
plants
c)
decomposers
d)
animals
9.
A close association between two or more species that live together is called a __ relationship. This association can be mutualistic, parasitic, or commensalistic.
a)
symbiotic
b)
biosphere
c)
food web
d)
food chain
10.
What is the biosphere?
a)
the relatively thin layer of Earth and its atmosphere that supporst life
b)
biological community and all the nonliving factors that affecet it
c)
physical area where an organism lives
d)
all the interacting populations of a different species that live in the same geographic location at the same time
11.
How can detritivores be beneficial to the environment?
a)
rid waste and dead matter
b)
provide food for autotrophs
c)
facilitate photosynthesis in plants
d)
allow predation to occur
12.
What is a trophic level?
a)
each step in a food chain or food web
b)
chemical substance that living organisms obtain from the environment to carry out life processes and sustain life
c)
model that shows many interconnected food chains and pathways in which energy and matter flwo through an ecosystem
d)
simplified model that shows a single path for energy flow through an ecosystem
13.
What is matter?
a)
anything that has mass and takes up space
b)
the ability to do work
c)
a combination of two or more substances in which each retains its individual properties
d)
a pure substance formed when two or more atoms combine
14.
What is parasitism?
a)
symbiotic relationship in which one organism benefits at the expense of another organism
b)
symbiotic relationship in which one organism benefits and the other organism is neither helped nor harmed
c)
symbiotic relationship in which both organisms benefit
15.
Mia takes an early morning hike through a forest near her home. She spots white-tailed deer browsing on undergrowth vegetation and a raccoon eating an apple and tuna that were care‐ lessly left behind by another hiker. Mia discovers bright yellow mushrooms growing on a rotting log, and she gazes up at oak trees rising 100 m above the ground. Mia shares her observations with workers at the local nature center. Which would Mia share with the center’s ecologist?
a)
The raccoon is an omnivore because it eats plants and animals.
b)
The white-tailed deer are considered carnivores of forest plants.
c)
The oak trees and mushrooms are two types of forest autotrophs.
d)
All the organisms spotted during the hike are heterotrophs.
16.
Which is an example of mutualism?
a)
a fish protecting a shrimp, who builds a burrow for the pair to share
b)
a peacock courting and mating with a peahen
c)
crayfish and minnows resting under the same rock
d)
two snake species with similar markings advertising their toxic venom
17.
What is mutualism?
a)
symbiotic relationship in which both organisms benefit
b)
symbiotic relationship in which one organism benefits and the other organism is neither helped nor harmed
c)
symbiotic relationship in which one organism benefits at the expense of another organism
18.
Ecologists often use modeling, instead of field studies, because it __.
a)
allows them to control all of the variables involved
b)
is less expensive than working in the field
c)
lets them study many organisms at once
d)
helps them collect more samples
19.
In which scientific study would an ecologist take part?
a)
observe how coral colonizes a sunken ship
b)
compare fossilized ant species in amber
c)
classify three new rain forest insect species
d)
assess the rabies risk of wild raccoons
20.
What is a climax community?
a)
stable, mature ecological community with little change in the composition of species
b)
group of organisms of the same species that occupy the same geographic area at the same time
c)
biological community and all the nonliving factors that affect it
d)
all the interacting populations of a different species that live in the same geographic location at the same time
21.
What is primary succession?
a)
establishment of a community in an area of bare rock or bare sand, where no topsoil is present
b)
orderly change that occurs in a place where soil remains after a community of organisms has been removed
c)
average weather conditions in a specific area, determined by latitude, elevation, ocean currents, and other factors
d)
process by which one community replaces another community because of changing abiotic and biotic factors
22.
Which is a characteristic of a savanna?
a)
grasses with trees intermixed
b)
layer of frozen soil
c)
areas of thick forests
d)
sand and rocky terrain
23.
Which defines a biome as a desert?
a)
rate of evaporation higher than precipitation
b)
area with no organic matter in soil
c)
annual rainfall less than 10 cm/yr
d)
a region of few or no trees
24.
Mario and several friends spend a day at the beach. While watching the ocean waves crashing to shore, Mario wonders how much of the world’s water is contained in different types of bodies of water such as oceans, lakes, and rivers. He decides to research the percentage of Earth’s wa‐ ter found in different locations. Which does his research reveal?
a)
Less than 3 percent of Earth’s water is freshwater containing no salt.
b)
The ice caps located at both poles contain 30 percent of Earth’s water.
c)
Ninety percent of Earth’s water is in lakes, rivers, and groundwater.
d)
Fifty percent of Earth’s water is in oceans and the glaciers at the poles.
25.
What is ecological succession?
a)
process by which one community replaces another community because of changing abiotic and biotic factors
b)
orderly change that occurs in a place where soil remains after a community of organ isms has been removed
c)
establishment of a community in an area of bare rock or bare sand, where no topsoil is present
d)
distance of a point on Earth's surface north or south of the equator
26.
Emily and her family live in Maine, and they have planned a road trip to travel across Canada and the United States. They travel across Canada through forests of spruce and fir trees until they reach the west coast. Traveling south through temperate rain forests, they reach southern California, where only shrubs grow in dry soil. Heading east, they pass through deserts and eventually reach the deciduous forests of the east coast. They drive northward to home. Which describes Emily’s cross-country trip?
a)
The trip encompassed a majority of the major terrestrial biomes of Earth.
b)
They traveled through several large ecosystems such as the American desert
c)
The family spent their entire trip in the North American biological community
d)
Emily witnessed a series of ecosystem successions such as scrubland to desert.
27.
What is the difference between the terms weather and climate?
a)
Weather is the atmospheric conditions such as temperature and precipitation at a specific time and place, and climate is the average weather of a location.
b)
Climate and weather mean the same thing.
c)
Climate is the atmospheric conditions such as temperature and precipitation at a specific time and place, and weather is the average climate of a location.
d)
Weather is the average temperature of a location, while a climate is the location itself.
28.
What would an ecologist use latitude to describe?
a)
the distance of a point from the Earth's equator
b)
the distance of a point from Earth's prime meridian
c)
the average weather conditions of a specific location
d)
the distance of a point from the Earth's north pole
29.
Which explains why secondary succession generally occurs more rapidly in an area than does primary succession?
a)
Soil formation has already occurred.
b)
Average precipitation is higher.
c)
Moderate climatic conditions exist.
d)
Pioneer species are microscopic.
30.
Conifer trees dominate boreal forests rather than tundra because of __.
a)
a lack of permanently frozen soil
b)
direct rays of light hitting the biome
c)
mild climatic and weather conditions
d)
the absence of better adapted trees
31.
The first organisms to appear during ecological succession are called ____.
a)
pioneer species
b)
end point species
c)
succession plants
d)
primary organisms
32.
What is secondary succession?
a)
orderly change that occurs in a place where soil remains after a community of organ isms has been removed
b)
atmospheric conditions such as temperature and precipitation at a specific time and place
c)
establishment of a community in an area of bare rock or bare sand, where no topsoil is present
d)
process by which one community replaces another community because of changing abiotic and biotic factors
33.
What are two features of coral reefs?
a)
prevent shore erosion and live symbiotically with algae
b)
exist in abyssal zone and lack polyps
c)
exist in benthic zone and kill off other sea life
d)
cause shore erosion and act as a parasite to algae
34.
Which biome occurs in the United States and once contained huge herds of grazing herbivores?
a)
grassland
b)
savanna
c)
boreal forest
d)
temperate forest
35.
Which is a characteristic of exponential population growth?
a)
Resources are consumed exponentially during all phases.
b)
The lag phase follows rapid growth.
c)
Initial population growth is rapid.
d)
Growth rate is inversely proportional to population size.
36.
Which of the following is true of a population with a growth rate of zero with no emigration or immigration?
a)
The birthrate equals the death rate.
b)
The birthrate exceeds the death rate.
c)
The birthrate is less than the death rate.
37.
Which is not used to describe a population of grizzly bears in Canada?
a)
demographic history
b)
geographic distribution
c)
population range
d)
population density
38.
What happens when a population nears carrying capacity?
a)
Resources become scarce.
b)
Resources become abundant.
c)
Disease spreads less easily.
d)
Density independent factors increase.
39.
Why is disease considered a density-dependent environmental factor?
a)
Population density affects amount of contact
b)
Disease spreads easily in a low-density population.
c)
Disease won't spread in high-density populations.
d)
Disease may be influenced by weather.
40.
Which factor is an environmental factor that depends on population numbers?
a)
density-dependent factor
b)
density-independent factor
c)
climate factor
d)
growth factor
41.
What is species diversity?
a)
in a biological community, the number and abundance of different species
b)
variety of inheritable characteristics or genes in an interbreeding population
c)
any different environmental condition occurring along an ecosystem's boundaries
d)
variety of ecosystems in the biosphere
42.
What is a mass extinction?
a)
a large-scale dying out of a large percentage of all living organisms in an area within a short amount of time
b)
gradual process of a species becoming extinct
c)
habitat loss from separation of an ecosystem into small pieces of land
d)
overuse of a species with economic value
43.
Which defines extinction?
a)
A species disappears.
b)
An ecosystem vanishes.
c)
Biodiversity decreases.
d)
Genetic diversity drops.
44.
Which organisms are affected most by biological magnification?
a)
wolves
b)
mice
c)
algae
d)
plants
45.
Because the world’s cheetahs have little variation in their DNA, the total population of this animal has low __.
a)
genetic diversity
b)
population diversity
c)
ecosystem diversity
d)
species diversity
46.
Eutrophication is a type of pollution in which:
a)
phosphorus-rich and nitrogen-rich substances flowing into waterways cause algal overgrowth
b)
pollutants from car exhaust dissolve in water in the atmosphere, creating acid rain
c)
hydrocarbons from oils spill into water sources, poisoning fish and other wildlife
d)
carbon compounds released into the air cause the green-house effect
47.
What is genetic diversity?
a)
variety of inheritable characteristics or genes in an interbreeding population
b)
number of different species living in a specific area
c)
variety of ecosystems in the biosphere
d)
in a biological community, the number and abundance of different organisms
48.
What causes the edge effect in habitats?
a)
fragmentation of habitat
b)
eutrophication
c)
destruction of habitat
d)
biological magnification
49.
Which is an example of genetic diversity within a rain forest?
a)
all of the genes found within the ecosystem
b)
wide variety of beetle species
c)
DNA of a single three-toed sloth
d)
many variations of jaguar spots
50.
While touring a Costa Rican rain forest on vacation, Dana learns that rain forests have the highest biodiversity of any ecosystem on the planet. The guide defines the term biodiversity for the group. Which definition does she give?
a)
variety of habitats in the forest
b)
number of life layers in the forest
c)
number of organisms in the forest
d)
variety of species in the forest
51.
Which statement is true of chemical equations?
a)
Reactants come before the arrow, products come after.
b)
Reactants come after the arrow, products come before.
c)
Reactants and products come before the arrow.
d)
Reactants and products both come after the arrow.
52.
To develop a product that warms people's hands, would you use an exothermic or endothermic reaction? Why?
a)
Exothermic; that way the reaction will release heat.
b)
Endothermic; that way the reaction will release heat.
c)
Exothermic; that way the reaction will absorb heat.
d)
Endothermic; that way the reaction will absorb heat.
53.
Which of the following statements is true?
a)
All molecules are compounds.
b)
All compounds are molecules.
c)
Molecules are made up of ionic bonds.
d)
Compounds are only composed of covalent bonds.
54.
How are water molecules in a rain drop held together?
a)
van der Waals forces
b)
attraction between positive charges
c)
attraction between negative charges
d)
ionic bonds
55.
What is the ratio of carbohydrates in a monosaccharide?
a)
1 carbon: 2 hydrogen: 1 oxygen
b)
1 carbon: 3 hydrogen: 1 oxygen
c)
2 carbon: 1 hydrogen: 2 oxygen
d)
1 carbon: 2 hydrogen: 2 oxygen
56.
How do enzymes affect a chemical reaction, making it easier to occur?
a)
They reduce the activation energy.
b)
They make the reaction exothermic.
c)
They make the reaction endothermic.
d)
They raise the activation energy.
57.
In a carbon dioxide molecule (O=C=O), which statement is true of the electrons?
a)
The electrons are being shared between the carbon and oxygen atoms.
b)
The electrons are involved in ionic bonding.
c)
The oxygens have gained electrons, giving them a negative charge.
d)
The electrons are involved in ionic bonding.
58.
Which macromolecule is responsible for the formation of a cell's membrane?
a)
lipids
b)
nucleic acids
c)
carbohydrates
d)
proteins
59.
Which macromolecule stores genetic information for an organism?
a)
nucleic acid
b)
carbohydrate
c)
lipid
d)
proteins
60.
Why must the number and type of atoms in the reactants equal the number and type atoms in the products formed?
a)
The law of conservation of mass says matter cannot be created or destroyed.
b)
Atoms are converted to other elements by chemical reactions.
c)
Chemical processes convert between matter and energy.
d)
Energy released by an exothermic reaction must balance energy absorbed by an endothermic one.
61.
Which macromolecule is involved in nearly every function in the human body?
a)
proteins
b)
nucleic acid
c)
carbohydrate
d)
lipid
62.
Which statement is not true about pure water?
a)
It is composed of ionic bonds.
b)
It is a good solvent.
c)
It is composed of polar molecules.
d)
It is adhesive and cohesive due to hydrogen bonds.
63.
Why is the active site of an enzyme important to enzyme activity?
a)
It allows the enzyme to catalyze very specific reactions.
b)
It raises the activation energy of a reaction.
c)
It allows the enzyme to interact with a large variety of substrates.
d)
It allows an endothermic reaction to run as an exothermic reaction.
64.
Which of the following best describes atoms?
a)
Atoms are made of three particles called electrons, neutrons, and protons.
b)
Atoms are hard, solid balls of matter that are the smallest known particles.
c)
Atoms are composed of electrical charges that are made only of energy.
d)
Atoms are made of uniform sphere called a nucleus surrounded by electrons
65.
Which of the following can be classified as a van der Waals force?
a)
a weak electrostatic interaction between two polar molecules
b)
strong electrostatic interaction between two atoms in an ionic bond
c)
a non-polar covalent bond
d)
a polar covalent bond
66.
What is the function of the nuclear envelope?
a)
It surrounds the nucleus by a double membrane.
b)
It stores genetic information for protein production.
c)
It allows larger-sized substances to move in and out of the nucleus
d)
It produces ribosomes.
67.
How do carrier proteins facilitate active transport?
a)
Carrier proteins move substances from a low to high concentration.
b)
Carrier proteins block the plasma membrane.
c)
Carrier proteins create an isotonic solution.
d)
Carrier proteins move substances from a high to low concentration.
68.
What is the function of the nuclear pores?
a)
They allow larger-sized substances to move in and out of the nucleus.
b)
It surrounds the nucleus by a double membrane.
c)
It stores genetic information for protein production.
d)
It produces ribosomes.
69.
What is the definition of selective permeability?
a)
It is the property of the plasma membrane that allows it to control movement of substances into or out of the cell.
b)
It moves needed substances or waste materials through the plasma membrane.
c)
It is the process of maintaining balance in an organism's internal environment.
d)
It is layers composed of phospholipid molecules arranged with polar heads facing outside and non-polar tails facing the inside.
70.
Which organelle is large in plant cells but small or absent in animal cells?
a)
vacuole
b)
chloroplast
c)
centriole
d)
nucleolus
71.
The condition of continuous, random movement of particles but no overall change in concentration of materials is called __.
a)
dynamic equilibrium
b)
diffusion
c)
osmosis
d)
passive transport
72.
During the nineteenth century, many scientists and naturalists studied microscopic organisms using magnifying lenses and simple microscopes. After studying plant tissues, animal tissues, and protozoans under the microscope, scientists summarized their observations of cells and for‐ mulated the cell theory. Which would not be included as part of the cell theory?
a)
Unicellular organisms can grow from organic molecules.
b)
Cells are the building blocks of living structures.
c)
Parent cells pass genetic material on to daughter cells.
d)
All living things are made of one or more cells.
73.
What is the function of the smooth ER?
a)
A variety of complex carbohydrates and lipids are synthesized.
b)
Proteins are synthesized and produced
c)
It surrounds the nucleus with a double membrane.
d)
Carbohydrates, lipids, and other substances are consumed.
74.
Which defines a cell?
a)
the basic unit of living things
b)
microscopic organisms in water
c)
the smallest type of animal
d)
protein molecules in animals
75.
Which of the following is not a main factor that affects the rate of diffusion?
a)
conductivity
b)
pressure
c)
temperature
d)
concentration
76.
Predict how oxygen crosses the plasma membrane if the concentration of oxygen is lower inside the cell than it is outside the cell.
a)
Oxygen enters the cell through the plasma membrane.
b)
Oxygen enters the cell through channel proteins.
c)
Oxygen leaves the cell through channel proteins.
d)
Oxygen leaves the cell through the plasma membrane.
77.
A molecule that is important for cell functioning cannot diffuse through the plasma membrane, but needs a protein that can open and close to allow the molecule to diffuse. What is this protein called?
a)
channel protein
b)
motor protein
c)
receptor protein
d)
carrier protein
78.
Which organelle produces protein for a cell?
a)
ribosome
b)
nucleus
c)
endoplasmic reticulum
d)
Golgi apparatus
79.
What is homeostasis?
a)
the process of maintaining balance in an organism’s internal environment
b)
a membrane which allows some substances to pass through while keeping others out
c)
the ability to arrange phospholipids in a way that allows the plasma membrane to tolerate the watery environment
d)
the ability to move needed substances or waste materials through the plasma membrane
80.
Science students in Alma’s class are observing prepared slides of the cells of maple tree leaves and mammal skin cells. As they study the cells under the microscope’s highest magnification, their teacher records their observations on the board. Which would be included in the teacher’s list?
a)
The leaf cells have green organelles called chloroplasts; the animal cells do not.
b)
Both the animal and plant cells have an oval shape and are about the same size.
c)
The skin cells have a nucleus, but the cells of the leaves have no nucleus.
d)
Both types of cells have a membrane that is also surrounded by a cell wall.
81.
Which organelle is present in a paramecium protozoan but absent in the cells of a strawberry plant?
a)
cilia
b)
microtubules
c)
nucleus
d)
cytoskeleton
82.
What is the definition of the cell theory? It states that:
a)
Organisms are made of one or more cells, cells are the basic unit of life, and all cells come only from other cells.
b)
All cells have a plasma membrane and genetic material called DNA.
c)
Eukaryotic cells are larger than prokaryotic cells.
d)
The cell is the basic structural and functional unit of all living organisms.
83.
Which of the following characteristics would a river need in order to maintain a highly diverse ecosystem?
a)
Fast-moving water
b)
slow-moving water
c)
nutrients from erosion
d)
high altitude
e)
oxygen mixed into the water
84.
What are two features of coral reefs?
a)
prevent shore erosion
b)
live symbiotically with algae
c)
lack polyps
d)
hazardous to most sea life
e)
exist in the abyssal zone
85.
Select examples of density-independent factors. Select all that apply
a)
competition
b)
flooding
c)
disease
d)
drought
e)
forest fires
86.
What might be happening when a population stops increasing and begins decreasing? Select all that apply.
a)
immigration exceeds emigration
b)
the number of births is less than the number of deaths
c)
the number of births exceed the number of deaths
d)
emigration exceeds immigration
87.
Which of the following are characteristics of invasive species. Select all that apply.
a)
reproduce at a sustainable rate
b)
consume natural resources at a rate that cannot be sustaines
c)
population is not limited by predators or local environmental factors
d)
introduced species with no natural predators
e)
compete with other organisms to the point of eradication
88.
Which of the following are examples of overexploitation? Select all that apply
a)
a farmer planting trees for each one he cuts down to sell as lumber
b)
a species of tree declining in population as they are harvested for wood by lumber workers
c)
a species of bird in danger of extinction because they are continuously hunted by humans and not allowed to recover
d)
a species of turtle going extinct as their preferred food source becomes unavailable
e)
whales being hunted by whalers for oil products faster than they can reproduce
89.
Which of the following compounds are examples of nucleic acids? Select all that apply.
a)
ribonucleic acid (RNA)
b)
amino acids
c)
fatty acids
d)
polysaccharides
e)
deoxyribonucleic acid (DNA)
90.
What are the major classes of biological macromolecules? Select all that apply.
a)
carbohydrates
b)
acids
c)
proteins
d)
lipids
e)
nucleic acids
91.
Which of the following statements are principles of the cell theory? Select all that apply.
a)
Cells are the basic unit of life.
b)
Cells reproduce by binary fission.
c)
Cells come from preexisting cells.
d)
Cells contain membrane-bound organelles.
e)
All living organisms are composed of cells.
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