Life Science 1
The diagram below represents an ecosystem food chain.
grass and shrubs → elk → wolves
People in this community have decided that the wolves are a threat to livestock. Humans hunt the wolves to extinction in this ecosystem. What will most likely happen to the elk population as a result of the extinction of the wolves?
The elk population will increase, which will decrease the amount of grasses and shrubs required to support the elk population.
The list below describes the relationship between an ant species and a tree species.
• The ants protect the tree by stinging any animal that might try to eat the tree’s leaves. The ants also eat any plant that tries to grow around the tree.
• The tree produces nectar that the ants can eat. The tree also provides shelter for the ants.
How is the relationship between the ants and the tree classified?
mutualism
A potato farmer uses animal-waste fertilizer. Runoff from the farm leads directly to a nearby creek. What should the farmer do to ensure there is no impact on the environment?
take regular water samples from the creek to check for nitrates
Which choice provides the best description of hydroelectric energy?
A It is a renewable energy resource because this form of energy is easily replenished by the water cycle.
B It is a renewable energy resource because this form of energy removes greenhouse gases from the atmosphere.
C It is a nonrenewable energy resource because this form of energy is not easily replenished by the water cycle.
D It is a nonrenewable energy resource because this form of energy contributes greenhouse gases to the atmosphere.
A It is a renewable energy resource because this form of energy is easily replenished by the water cycle.
A scientist pours two liquids into a flask and swirls the flask to combine the liquids. The scientist then places the flask on a laboratory workbench. After a few seconds, the liquids separate into layers. How are the contents of the flask classified?
as a heterogeneous mixture
A scientist places two bacteria species, X and Y, into a test tube containing sugar water. Both bacteria species consume sugar as a food source. After some time, the scientist observes the number of species X cells has increased, and the number of species Y cells has decreased. Which choice explains the scientist’s observation?
The bacteria engaged in competition, and species X was more successful than species Y.
A squirrel population lives in a forest ecosystem. Some squirrels are born with thick fur, and others are born with thin fur. The list below describes the advantage of each fur type.
• Thick fur helps keep heat contained around the squirrel’s body.
• Thin fur helps release heat quickly to the environment. Suppose the climate of the forest changes. Average daily temperatures decrease, producing cooler summers and much colder winters.
How will this climate change affect the squirrel population?
The squirrels with thick fur will be more likely to survive and pass on their genes to the next generation.
Which choice describes the relationship between the salinity of ocean water, evaporation, and transpiration?
A Transpiration decreases the salinity of ocean water, and evaporation has no effect. B Transpiration increases the salinity of ocean water, and evaporation has no effect.
C Evaporation decreases the salinity of ocean water, and transpiration has no effect. D Evaporation increases the salinity of ocean water, and transpiration has no effect.
D Evaporation increases the salinity of ocean water, and transpiration has no effect.
A hydroelectric power plant is experiencing a significant reduction in electricity output. Which scenario best explains why this might happen?
A The flow of water through the hydroelectric plant has increased because of an obstruction in the river downstream.
B The flow of water through the hydroelectric plant has increased because of an obstruction in the river upstream.
C The flow of water through the hydroelectric plant has decreased because of an obstruction in the river upstream.
D The flow of water through the hydroelectric plant has decreased because of an obstruction in the river downstream.
C The flow of water through the hydroelectric plant has decreased because of an obstruction in the river upstream.
Iron was melted and then cooled to form thin iron sheets. What type of change occurred during the melting and cooling?
A physical change occurred when the iron was melted and allowed to cool.
Why are people who may have become infected with a rare virus quarantined?
to prevent an epidemic from becoming a pandemic
Which choice is a product of photosynthesis?
A sunlight
B glucose
C carbon dioxide
D water
C carbon dioxide
What must be true if a geologic fault runs through a sedimentary rock layer?
A The fault is geologically older than the rock layer.
B The fault is geologically younger than the rock layer.
C The fault and the rock layer formed at the same time.
D The fault was created by volcanic activity
B The fault is geologically younger than the rock layer.
Where would most of the freshwater available on Earth be located?
glaciers and icebergs
The balanced equation below represents a chemical reaction.
FeS + 2HCl → FeCl2 + H2S
According to the law of conservation of mass, how many hydrogen and chlorine atoms are required for this reaction?
2 hydrogen atoms and 2 chlorine atoms
The list below describes the fossil remains of two extinct dinosaurs.
• Triceratops: a large dinosaur that walked on four legs. Its skull has a large bony plate behind the eye sockets and three horns.
• Stegoceras: a small dinosaur that walked on two legs. Its skull has a thick dome on top, but no horns.
What is the best way to study the evolutionary relationship between Triceratops and Stegoceras?
by comparing their skeletal systems (anatomy)
Gray foxes live in woodland habitats of North America. They have coat colors that are mixes of gray,
white, and brown. Gray foxes are the only type of foxes that can climb trees.
How do these adaptations help gray foxes survive in their habitats?
A The adaptations help them sneak up on and catch prey.
B The adaptations help them stay cool during warm summers.
C The adaptations help them hide their food for later use.
D The adaptations help them travel large distances.
A The adaptations help them sneak up on and catch prey.
Why is ocean water warmer near Earth’s equator than at its poles?
Sunlight near the equator is more intense than at the poles.
Which statement is true regarding the evidence found in the Earth's fossil record?
A Life forms existed on land before they existed in water.
B The oldest rock layers contain a larger variety of fossils.
C Very few life forms have become extinct over time.
D More complex life forms probably evolved from less complex life forms.
D More complex life forms probably evolved from less complex life forms.
Jeremy wants to create a model of a neutral chlorine atom with a mass number of 35. How many protons, electrons, and neutrons should appear in Jeremy’s model?
17 protons, 17 electrons, and 18 neutrons
A tree has a wound in its bark. The area around the wound becomes diseased. A scientist takes a sample from the wound and discovers a pathogen causing the disease has these characteristics:
• The pathogen is unicellular.
• The pathogen has no membrane-bound organelles.
• The pathogen is so small it can only be seen under a microscope.
How should the scientist classify this pathogen?
as a bacterium
Scientists studying a group of young sage grouse discovered a large percentage were infected with
blood parasites. How will these blood parasites most likely affect the young birds?
A by mutating the birds’ genetic traits
B by altering the birds’ social behaviors
C by decreasing the birds’ overall health
D by increasing the birds’ available energy
C by decreasing the birds’ overall health
A population of large fish has recently been discovered at a lake. The town council where the lake is located wants to increase tourism and will allow fishing at the lake. What action should the town council take to promote good environmental stewardship?
The council should establish rules to ensure that fishing is sustainable and has no impact on the long-term health of the fish.
What is an aquifer?
An aquifer is an underground layer of permeable rock that holds water, allowing it to be used as a source
of drinking water.
The list below describes how humans obtain table salt from the ocean.
• First, a person must collect some seawater in a shallow pool.
• Then, the water evaporates, leaving behind solid table salt.
• Lastly, a machine breaks the solid table salt into smaller pieces.
Which choice describes the changes that occurred in this scenario?
Both the seawater evaporating and the machine breaking the salt into smaller pieces are physical changes.