End Of Course Biology Test Prep

1. Which of these will complete the mRNA strand matched to DNA?

CAG

AUG

GUC

UAC

When mRNA gets transcribed from DNA during gene expression, complementary bases are brought in to complete the mRNA strand. Since RNA doesn't have the base Thymine like DNA, Adenine gets paired with the nitrogen base Uracil found in RNA. Cytosine and Guanine always pair up. Therefore, the correct answer would be letter C.

Explanation

When mRNA gets transcribed from DNA during gene expression, complementary bases are brought in to complete the mRNA strand. Since RNA doesn't have the base Thymine like DNA, Adenine gets paired with the nitrogen base Uracil found in RNA. Cytosine and Guanine always pair up. Therefore, the correct answer would be letter C.

2. A young patient is diagnosed with the genetic disorder lactose intolerance, which results in the inability to digest milk products due to a missing enzyme called lactase. What is most likely the cause of lactose intolerance in this patient?

The patient is allergic to milk

The patient stopped consuming milk products

A disease destroyed the lining of the patient’s small intestine

A mutation occurred in the gene that is responsible for producing lactase

Since genes code for proteins and enzymes are proteins, a mutation in a gene may result in a failure by the body to produce a needed enzyme. Therefore, the correct answer is D.

Explanation

Since genes code for proteins and enzymes are proteins, a mutation in a gene may result in a failure by the body to produce a needed enzyme. Therefore, the correct answer is D.

3. If an animal cell is placed in distilled water, it will swell and burst. The bursting of the cell is a result of which biological process?

Active transport

Enzyme activity

Osmosis

Respiration

Osmosis is the process by which water passively diffuses across a cell membrane from an area of higher water concentration to a lower one. Therefore, the correct answer is A.

Explanation

Osmosis is the process by which water passively diffuses across a cell membrane from an area of higher water concentration to a lower one. Therefore, the correct answer is A.

4.

In an experiment, chickens were fed grain that contained a chemical marker in its proteins. The presence of the marker can be detected in organisms. Which of the following is the most reasonable prediction from this experiment?

The marker will only be found in the grain.

Both chickens and wolves will have the marker.

Wolves will have the marker, but chickens will not.

The marker will only be found in the animals' wastes.

You are what you eat and what you eat eats. Therefore, B is the correct answer.

Explanation

You are what you eat and what you eat eats. Therefore, B is the correct answer.

5.

At position Y, carbon is most likely to be in which of the following forms?

Protein

Solid Carbon

Carbohydrate

Carbon Dioxide

As part of the carbon cycle plants take in carbon dioxide from the atmosphere (Letter Y). Animals take in carbon from carbohydrates produced by plants (Letter X). Choice D is the correct answer.

Explanation

As part of the carbon cycle plants take in carbon dioxide from the atmosphere (Letter Y). Animals take in carbon from carbohydrates produced by plants (Letter X). Choice D is the correct answer.

6.

Which of the following diagrams correctly represents an energy pyramid from this web?

Energy Pyramid A

Energy Pyramid B

Energy Pyramid C

Energy Pyramid D

If you follow the arrows in the food web, green algae get eaten by limpets, which get eaten by crabs who get eaten by gulls. Since algea are at the bottom of the food web, they must have the greatest amount of energy to support everything above it in the pyramid.

Explanation

If you follow the arrows in the food web, green algae get eaten by limpets, which get eaten by crabs who get eaten by gulls. Since algea are at the bottom of the food web, they must have the greatest amount of energy to support everything above it in the pyramid.

7.

If many trees are removed from a forest, what is the most immediate effect on the carbon cycle in that forest?

Increased rates of decomposition

Decreased use of atmospheric CO2

Decreased combustion of fossil fuels

Increased production of organic compounds

If there are less trees in the forest, there will be less plants to take up carbon dioxide. Therefore, the answer is B.

Explanation

If there are less trees in the forest, there will be less plants to take up carbon dioxide. Therefore, the answer is B.

8. During meiosis, homologous chromosomes can exchange DNA in a process known as –

Replication

Cytokinesis

Crossing over

Internal fertilization

When sex cells are produced through the process of meiosis, homologous chromosomes swap genetic material in a process known as crossing over, The correct answer is C.

Explanation

When sex cells are produced through the process of meiosis, homologous chromosomes swap genetic material in a process known as crossing over, The correct answer is C.

9. Timothy has attached earlobes. His mother and father both have free earlobes, which are dominant. Which statement explains how Timothy inherited attached earlobes?

He received a recessive allele from each parent

He received a dominant allele from each parent

He received a recessive allele from his mother and a dominant allele from his father

He received a dominant allele from his mother and a recessive allele from his father

The only way for Timothy to express the recessive trait would be to carry two alleles for the recessive trait. Therefore, he would have had to get one recessive allele from each parent, which would make A the correct answer.

Explanation

The only way for Timothy to express the recessive trait would be to carry two alleles for the recessive trait. Therefore, he would have had to get one recessive allele from each parent, which would make A the correct answer.

10.

A food web is shown below. Which of the following is most likely to lead to an increase in the number of foxes over time?

A decrease in owls

An increase in hawks

An increase in mountain lions

A decrease in raspberry bushes

If the owl population decreases, the hawk population will have less competition for rabbits and sparrows and will be able to increase. Therefore, A is the correct answer.

Explanation

If the owl population decreases, the hawk population will have less competition for rabbits and sparrows and will be able to increase. Therefore, A is the correct answer.

11. Lemurs' bodies are adapted to efficiently store energy for times when food is scarce. This adaptation may help to explain how lemur ancestors survived the trip across the Mozambique Channel from mainland Africa to Madagascar. Which of the following types of molecules are primarily used for long-term energy storage in the lemur?

Lipids

Carbohydrates

Nucleic Acids

Proteins

Carbohydrates are used by organisms as an immediate source of energy, nucleic acids serve as hereditary material for organisms, proteins are primarily used to build and repair tissue and lipids are used by organisms to store energy. Therefore the correct answer is A.

Explanation

Carbohydrates are used by organisms as an immediate source of energy, nucleic acids serve as hereditary material for organisms, proteins are primarily used to build and repair tissue and lipids are used by organisms to store energy. Therefore the correct answer is A.

12.

Which hypothesis would most likely be tested using this setup?

Green water plants release a gas in the presence of light.

Roots of water plants absorb minerals in the absence of light.

Green plants need light for cell division.

Plants grow best in the absence of light.

The only difference between the two experimental set ups is the presence of light and the gas bubbles in the experimental set up with light. Therefore, the correct answer would be A. (Plants release oxygen gas as a byproduct of photosynthesis).

Explanation

The only difference between the two experimental set ups is the presence of light and the gas bubbles in the experimental set up with light. Therefore, the correct answer would be A. (Plants release oxygen gas as a byproduct of photosynthesis).

13. Which of the following best describes the result of a mutation in an organism's DNA?

The mutation may produce a zygote.

The mutation may cause phenotypic change.

The mutation causes damage when it occurs.

The mutation creates entirely new organisms.

Mutations may be positive, negative or neutral. Mutations can cause phenotypic changes or physical changes in an organism's traits, which may be beneficial to their survival or detrimental to their survival. Therefore, the correct answer is B.

Explanation

Mutations may be positive, negative or neutral. Mutations can cause phenotypic changes or physical changes in an organism's traits, which may be beneficial to their survival or detrimental to their survival. Therefore, the correct answer is B.

14. In one of the steps of the carbon cycle, a person exhales a molecule of carbon dioxide (CO2) into the atmosphere. Which of the following is most likely to happen next to the atom of carbon in this molecule?

It may be used as part of a sugar in a plant.

It may become part of a protein in an animal.

It may be consumed as a fossil fuel is burned.

It may be decomposed into carbon and oxygen by a bacterium.

Humans breath out carbon dioxide as a waste product of cellular respiration and plants use the carbon from the carbon dioxide to make high energy sugars (glucose) during photosynthesis. This is why A is the correct answer.

Explanation

Humans breath out carbon dioxide as a waste product of cellular respiration and plants use the carbon from the carbon dioxide to make high energy sugars (glucose) during photosynthesis. This is why A is the correct answer.

15. On island chains like the one shown below, animal populations that spread from the main island to the other islands can evolve into separate species. Which of the following best explains what favors speciation in these situations?

Predators on the main island can easily migrate to follow the populations to the other islands.

Lack of disease on the other islands enables the populations to grow and change without limit.

The physical separation of the islands limits gene flow and interbreeding between the populations.

The climatic conditions of the islands allow the populations to breed all year and produce several generations

Different species form when two different populations get seperated until they can no longer reproduce to produce fertile offspring. Therefore, choice C is the correct answer.

Explanation

Different species form when two different populations get seperated until they can no longer reproduce to produce fertile offspring. Therefore, choice C is the correct answer.

16. Which of the following best explains why enzymes are necessary for many cellular reactions?

Enzymes supply the oxygen necessary for the reactions.

Enzymes change reactants from solid to liquid during the reactions.

The reactions take up too much space in the cell if enzymes are missing

The reactions are too slow to meet the needs of the cell if enzymes are missing.

Enzymes are a group of proteins responsible for speeding up chemical reactions. Therefore, the correct answer is D.

Explanation

Enzymes are a group of proteins responsible for speeding up chemical reactions. Therefore, the correct answer is D.

17. Fireflies produce light inside their bodies. The enzyme luciferase is involved in the reaction that produces the light. Scientists have isolated the luciferase gene. A scientist inserts the luciferase gene into the DNA of cells from another organism. If these cells produce light, the scientist knows that which of the following occurred?

The luciferase gene mutated inside the cells.

The luciferase gene was transcribed and translated.

The luciferase gene destroyed the original genes of the cells.

The luciferase gene moved from the nucleus to the endoplasmic reticulum.

If a gene is expressed it gets transcribed and translated into the appropriate enzyme. This makes B is the correct answer choice.

Explanation

If a gene is expressed it gets transcribed and translated into the appropriate enzyme. This makes B is the correct answer choice.

18. Scientists have concluded that snakes evolved from an ancestor with legs. Which of the following statements provides the best evidence for this conclusion?

Most species of snakes live on land.

Snakes move extremely fast to catch their prey

Snakes have a well-developed backbone and muscular system.

Some species of snakes have limb buds during their embryonic development.

Many organisms have characteristics during embryological development that disappear as they continue to develop, such as the limb buds found in snakes and whales, which suggests that they evolved from ancestors who once had 4 limbs. This indicates choice D is the best answer.

Explanation

Many organisms have characteristics during embryological development that disappear as they continue to develop, such as the limb buds found in snakes and whales, which suggests that they evolved from ancestors who once had 4 limbs. This indicates choice D is the best answer.

19. A carrot cell contains 18 chromosomes. Which of the following is the correct number of chromosomes in new cells produced by mitosis?

9

18

36

54

Mitosis ends with 2 daughter cells that have the same genetic composition as the parent cell. This is why B is the correct answer choice.

Explanation

Mitosis ends with 2 daughter cells that have the same genetic composition as the parent cell. This is why B is the correct answer choice.

20. Which of the following best explains how the fossil record provides evidence that evolution has occurred?

It indicates that forms of life existed on Earth at least 3.5 billion years ago.

It indicates the exact cause of structural and behavioral adaptations of organisms.

It shows how the embryos of many different vertebrate species are very similar.

It shows that the form and structure of groups of organisms have changed over time.

The fossil record very clearly shows that the vast majority of organisms who have ever lived on this planet have gone extinct, but adaptations in the form and structure of organisms have allowed related groups of organisms to evolve. Therefore, choice D is the correct answer.

Explanation

The fossil record very clearly shows that the vast majority of organisms who have ever lived on this planet have gone extinct, but adaptations in the form and structure of organisms have allowed related groups of organisms to evolve. Therefore, choice D is the correct answer.

21. An organism Jimsonweed, a common plant in New Jersey, has 12 chromosomes in its body cells. How many chromosomes will an egg cell of this plant have?

6 chromosomes

12 chromosomes

18 chromosomes

24 chromosomes

Sex cells have half the number of chromosomes as an organism's body cells. This is how you get half your genes from your mommy and half from your daddy. If an organism has 12 chromosomes in their body cells, their sex cells would have to have 6 chromosomes. This makes A the correct answer choice.

Explanation

Sex cells have half the number of chromosomes as an organism's body cells. This is how you get half your genes from your mommy and half from your daddy. If an organism has 12 chromosomes in their body cells, their sex cells would have to have 6 chromosomes. This makes A the correct answer choice.

22. Athletes want a drink to help them maintain constant cellular respiration during their game. To accomplish this goal, their drink should contain

ATP

Lipids

Glucose

Proteins

During cellular respiration an organism converts glucose into ATP. Therefore an athelete would have to get glucose from their drink to carry out cellular respiration. This makes choice C the correct answer.

Explanation

During cellular respiration an organism converts glucose into ATP. Therefore an athelete would have to get glucose from their drink to carry out cellular respiration. This makes choice C the correct answer.

23. Thousands of years ago, giraffes with short necks were common within giraffe populations. Nearly all giraffe populations today have long necks. This difference could be due to:

Giraffes stretching their necks to keep their heads out of reach of predators

Giraffes stretching their necks so they could reach food higher in the trees

A mutation in genetic material controlling neck size occurring in some skin cells of a giraffe

A mutation in genetic material controlling neck size occurring in the reproductive cells of a giraffe.

Only mutations in reproductive cells will get passed on to future generations to cause phenotypic changes such as a change in neck length. Therefore, the correct answer is D.

Explanation

Only mutations in reproductive cells will get passed on to future generations to cause phenotypic changes such as a change in neck length. Therefore, the correct answer is D.

24. Which two processes result in variations that commonly influence the evolution of sexually reproducing species?

Mitosis and natural selection

Extinction and gene replacement

Mutation and genetic recombination

Environmental selection and selective breeding

The two main sources of genetic variation for sexually reproducing organisms are mutations and genetic recombination. Mutation happen randomly upon exposure to mutagens and mistakes in DNA replication. Genetic recombination occurs during the production of sex cells when homologous chromosomes swap genetic material.

Explanation

The two main sources of genetic variation for sexually reproducing organisms are mutations and genetic recombination. Mutation happen randomly upon exposure to mutagens and mistakes in DNA replication. Genetic recombination occurs during the production of sex cells when homologous chromosomes swap genetic material.

25. Which of the following is NOT a function of the human skeletal system?

Support and structure

Protection of internal organs

Production of hormones

Mineral storage

The skeletal system provides support, structure, protection, and mineral storage. Hormone production is primarily the function of the endocrine system, involving glands like the pituitary, thyroid, and adrenal glands.

Explanation

The skeletal system provides support, structure, protection, and mineral storage. Hormone production is primarily the function of the endocrine system, involving glands like the pituitary, thyroid, and adrenal glands.