Question 1

Dutch elm disease is a fungal infection of elm trees that usually results in death.The disease has killed millions of NorthAmerican elm trees that were not resistant to the fungus. Scientists have bred resistant elms by crossing North American species with Asian species that show resistance.Which of the following best describes how natural selection would promote resistant elm populations once the resistance genes from the Asian species were successfully introduced?

Accepted Answer

A) After encountering elms with resistance genes, fungi would avoid elms and begin to attack other tree species. 
B) Resistance would spread to all of the mature elms in a population from the few trees that acquired the resistance genes. 
C) By reproducing with each other, elm trees with resistance genes would create super-resistant elms with twice the number of resistance genes. 
D) Elm trees with resistance genes would survive and pass on resistance to offspring, while trees without resistance would more likely be killed by the fungus.

Question 2

Fatty acids are one of the products that result from the action of lipase in the digestive system. What is one way that atty acids are used in the body?

Accepted Answer

A) for storing energy 
B) for encoding genetic information 
C) as the building blocks of antibodies 
D) as the building blocks of hemoglobin

Question 3

Hemoglobin is a protein that carries oxygen in red blood cells. The hemoglobin molecules produced by some people have one specific amino acid that is different from the amino acid at that position in normal hemoglobin.Which of the following is the most likely cause of this amino acid variation?

Accepted Answer

A) The hemoglobin gene contains a mutation. 
B) An error occurs during the folding of the hemoglobin protein. 
C) Enzymes replace the amino acid once the hemoglobin is produced. 
D) An additional amino acid is mistakenly inserted into the hemoglobin during translation.

Question 4

In sheep, the allele for white wool (W) is dominant, and the allele for black wool (w) is recessive. A farmer has mated two Suffolk sheep for a few years. These matings have resulted in six offspring, four with white wool and two ith black wool. One parent has white wool and the other has black wool.Which of the following could be the genotypes of the parent sheep?

Accepted Answer

A) WW and Ww 
B) WW and ww 
C) Ww and Ww 
D) Ww and ww

Question 5

The mold Aspergillus flavus grows on grain. A. flavus produces a toxin that binds to DNA in the bodies of animals that eat the grain. The binding of the toxin to DNA blocks transcription, so it directly interferes with the ability of an animal cell to do which of the following?

Accepted Answer

A) transport glucose across the cell membrane into the cytoplasm 
B) produce ATP using energy released from glucose and other nutrients 
C) transfer proteins from the endoplasmic reticulum to Golgi complexes 
D) send protein-building instructions from the nucleus to the cytoplasm and ribosomes

Question 6

The Asian shore crab invaded parts of the eastern coast of the United States about 15 years ago. The Asian shore crab preys on blue mussels. In the time since the Asian shore crab arrived, the average shell thickness has increased in the blue mussel population.Which of the following is the most likely reason that this increase in shell thickness has occurred?

Accepted Answer

A) Blue mussels with thick shells attract more crabs than mussels without thick shells. 
B) Blue mussels with thick shells grow in larger colonies than mussels without thick shells. 
C) Blue mussels with thick shells catch more food per day than mussels without thick shells. 
D) Blue mussels with thick shells survive and reproduce more successfully than mussels without thick shells.

Question 7

Some bacteria live in hot springs. Their cells contain enzymes that function best at temperatures of 70°C or higher.At a temperature of 50°C, how will the enzymes in these bacterial cells most likely be affected?

Accepted Answer

A) The enzymes will be destroyed by lysosomes. 
B) The enzymes will lose their bond structure and fall apart. 
C) The enzymes will require less energy to function than at 70°C. 
D) The enzymes will not increase the rate of reactions as much as they would at 70°C.

Question 8

Which of the following statements gives the most likely explanation for the presence of two very similar species of squirrels living on opposite sides of the Grand Canyon?

Accepted Answer

A) One squirrel traveled across the canyon and started a new population on the other side. 
B) One squirrel traveled across the canyon and interbred with a different population on the other side. 
C) Members of a single squirrel species were geographically separated by the formation of the canyon. 
D) Members of two different squirrel species migrated from two different places to opposite sides of the canyon.

Question 9

In July, a student tested the soil in two plots and calculated the concentration of nitrogen compounds present in each plot. The student then planted 20 seedlings in the first plot and allowed them to grow. Nothing was planted in the second plot. The student tested the soil in both plots again after one month. The concentration of nitrogen compounds had decreased in the first plot but had remained the same in the second plot. Which of the following best explains the decrease in nitrogen compounds in the first plot?

Accepted Answer

A) The nitrogen compounds had broken down into elements. 
B) The nitrogen compounds were absorbed by the seedlings for their growth. 
C) The nitrogen compounds escaped through air pockets created by the seedlings' roots. 
D) The nitrogen compounds had evaporated because of the warm summer temperatures.

Question 10

Which of the following elements is most common in the tissues of plants?

Accepted Answer

A) hydrogen 
B) iron 
C) potassium 
D) sodium

Question 11

All organisms classi?ed in kingdom Animalia must also be classi? ed as which of the following?

Accepted Answer

A) Archaea 
B) Eubacteria 
C) Eukaryota 
D) Protista

Question 12

During the fall reproductive season, the belly of a male brook trout becomes bright orange. The orange belly provides some camou?age and helps attract females. This trait evolved in brook trout because, compared to males with pale bellies, males with bright orange bellies are more likely to

Accepted Answer

A) live in good habitats. 
B) be eaten by predators. 
C) mate with other species of ? sh. 
D) fertilize eggs to produce offspring.

Question 13

According to Mendel's law of segregation, which of the following statements describes what happens to the alleles of a gene pair?

Accepted Answer

A) The alleles are moved to different chromosomes. 
B) The alleles are mutated in the process of mitosis. 
C) The alleles are separated during fertilization. 
D) The alleles are separated during gamete formation.

Question 14

Which of the following statements best describes the relationship of the kidneys and the liver to the circulatory system?

Accepted Answer

A) The kidneys and the liver pump blood. 
B) The kidneys and the liver produce blood cells. 
C) The kidneys and the liver remove wastes from blood. 
D) The kidneys and the liver make blood-clotting proteins.

Question 15

In the deserts of the southwestern United States, rock formations made from lava flows are found scattered across the sand. The rock pocket mouse, which has dark fur, lives on the black lava rocks. The Apache pocket mouse, which has light fur, lives on the tan sand.Which of the following statements best explains how these two types of mice could have evolved from a common ancestor?

Accepted Answer

A) Individual mice changed their fur color to escape their predators. 
B) Natural selection favored different fur colors in the different habitats. 
C) The emigration of mice changed the gene pools in the original population. 
D) The original population of mice spread out geographically to relieve overcrowding.

Question 16

Which of the following human activities reduces biodiversity?

Accepted Answer

A) prohibiting hunting in wildlife preserves 
B) taking tissue samples from members of endangered species 
C) planting only native grass species to prevent erosion beside highways 
D) planting only red pine trees to replace native hardwood forests cut for lumber

Question 17

In red blood cells, the compound carbonic anhydrase increases the rate at which carbon dioxide is converted to bicarbonate ions for transport in the blood. In red blood cells, carbonic anhydrase acts as which of the following?

Accepted Answer

A) an enzyme 
B) a hormone 
C) a lipid 
D) a sugar

Question 18

Fertilizers can enable farmers to grow the same crop in a ?eld for several years in a row. Farmers who use less fertilizer often rotate their crops by planting the crop one year and legumes, such as beans and clover, the following year. Fertilizer use and crop rotation with legumes both increase the availability of which of the following nutrients in soil?

Accepted Answer

A) calcium 
B) nitrogen 
C) oxygen 
D) protein

Question 19

Populations of Caribbean coral have decreased significantly over the past 30 years due to disease. Which of the following is most likely a major factor leading to the increased amount of disease in the coral?

Accepted Answer

A) Symbiotic algae are living in the coral cells. 
B) Several different species of fish live on the coral reefs. 
C) Levels of spawning have decreased and lowered reproductive rates. 
D) Water temperatures have increased and favored the growth of microorganisms.

Question 20

Starting in 1954, commercial fishers in the northwest Pacific were paid by weight, rather than by the individual fish, for pink salmon. The fishers increased the use of a type of net that selectively catches larger fish. Which of the following effects did this change in fishing techniques most likely have on the salmon population over the next 20 years?

Accepted Answer

A) The average body size of the salmon population increased significantly. 
B) The average body size of the salmon population decreased significantly. 
C) The average body size of the males in the salmon population increased and the average body size of females in the salmon population stayed the same. 
D) The average body size of the males in the salmon population stayed the same and the average body size of the females in the salmon population increased.

Exam 1: Biology