Question 1

Scientists have found geysers on one of Saturn's moons. The geysers release water vapor containing complex organic compounds, which may indicate the presence of life. Which of the following elements is most likely abundant in the organic compounds in the water vapor?

Accepted Answer

Organic compounds are primarily made up of carbon atoms, often bonded with hydrogen, oxygen, nitrogen, and other elements. Carbon's ability to form stable bonds with many elements, including itself, makes it the backbone of organic chemistry.

Question 2

The willow flycatcher is a bird species with a summer range throughout much of the United States. Which of the following would directly decrease the size of a willow flycatcher population in a given year?

Accepted Answer

The emigration of male willow flycatchers that did not secure territories would directly decrease the size of a willow flycatcher population in a given year, as it results in fewer birds remaining in the population to breed and contribute to its numbers.

Question 3

In pure water, a red blood cell from an animal will swell and burst, but a leaf cell from a plant will not. Which structure in the leaf cell is responsible for this difference?

Accepted Answer

The cell wall in plant cells provides additional support and protection against changes in osmotic pressure, preventing the cell from bursting when water enters, unlike animal cells which lack a cell wall.

Question 4

The atmosphere contains about 80% nitrogen gas, but nitrogen in this form cannot be used by plants. Which of the following processes converts atmospheric nitrogen to a useful form for plants?

Accepted Answer

Nitrogen fixation is the process by which atmospheric nitrogen is converted into a form (such as ammonia) that plants can absorb and use for growth.

Question 5

Which of the following processes produces the nucleotide sequence UUA from the sequence AAT?

Accepted Answer

Transcription is the process where the DNA sequence is copied into an RNA sequence. In this case, AAT in DNA would transcribe to UUA in RNA, where adenine (A) pairs with uracil (U) in RNA instead of thymine (T).

Question 6

The nose serves all the following functions except

Accepted Answer

The nose is responsible for providing an airway, moistening inhaled air, and filtering dust and particles from inhaled air. However, it does not transfer oxygen from the air to the bloodstream; this function is performed by the lungs.

Question 7

A population is separated into two groups by a geographic barrier. Over time, enough differences develop between the two groups that they do not interbreed when reunited. Which of the following terms best describes the process that has occurred?

Accepted Answer

The process described is speciation, which occurs when a population is divided by a geographic barrier, leading to the development of distinct species that do not interbreed when they come back into contact.

Question 8

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

The variation in the amino acid sequence of hemoglobin is most likely caused by a mutation in the hemoglobin gene. This mutation alters the DNA sequence, leading to the production of a hemoglobin protein with a different amino acid at a specific position.

Question 9

An invasive species of green algae has become established along the coasts of the Mediterranean Sea. Which of the following statements best explains why this species of algae has been so successful in the Mediterranean Sea?

Accepted Answer

The invasive species of green algae has been so successful in the Mediterranean Sea primarily because it is not eaten by many animals. This lack of natural predators allows the algae to proliferate without significant control, outcompeting native species and altering ecosystems.

Question 10

A person who is cold shivers to generate body heat. Which of the following lists the primary body systems that interact to maintain homeostasis in this situation?

Accepted Answer

Shivering is a response to cold initiated by the nervous system, which signals the muscles to contract (muscular system) to generate heat, while the circulatory system helps distribute the generated heat throughout the body, maintaining homeostasis.

Question 11

Every year, monarch butterflies from Canada and the United States spend the winter in central Mexico. The dry and mild climate in Mexico allows the monarch butterflies to survive the winter. One winter, a week of storms caused freezing temperatures and 43 cm of snow in Mexico. What was the most likely impact of these storms on the monarch butterflies?

Accepted Answer

Monarch butterflies are not adapted to survive freezing temperatures and heavy snowfall, so a sudden and severe change in weather like this would likely result in high mortality rates among the population.

Question 12

A researcher is studying a particular disease-causing agent. The agent has a protein coat, but it lacks a nucleus, contains no other organelles, and can reproduce only when it is inside an animal cell. The researcher should classify the agent as which of the following?

Accepted Answer

The agent described lacks a nucleus and other organelles and can only reproduce inside an animal cell, which are characteristics of a virus. Viruses have a protein coat and require a host cell to replicate, distinguishing them from bacteria, fungi, and protists, which are all cellular organisms.

Question 13

A pedigree is a diagram that traces the inheritance of a trait through a family. Which of the following patterns is typical in a pedigree for an autosomal dominant trait?

Accepted Answer

Autosomal dominant traits typically appear in every generation because only one copy of the mutant gene is needed for an individual to be affected. This means that if a parent has the trait, there is a 50% chance they will pass it on to each child, leading to its appearance in successive generations.

Question 14

Which of the following statements best describes why the change in only one DNA base of the hemoglobin gene results in a different protein product of the gene?

Accepted Answer

The change in a single DNA base (a point mutation) can alter the codon in mRNA, which in turn can change the amino acid incorporated into the protein during translation, thus altering the protein's structure and function.

Question 15

Which of the following cell structures carries out the process represented by the arrows labeled "2" in the diagrams?

Accepted Answer

The process represented by the arrows labeled "2" in diagrams typically refers to protein synthesis, which is carried out by ribosomes. Ribosomes are the cellular structures responsible for translating mRNA into proteins.

Question 16

Which of the following statements best summarizes a change that is represented by the arrows labeled "3" in the diagrams?

Accepted Answer

The answer of Which of the following statements best summarizes...

Question 17

Which of the following statements best compares individual Y and individual Z in terms of genotype and phenotype?

Accepted Answer

The individuals have different genotypes and different phenotypes.

Question 18

About 70 years ago, cane toads were introduced to Australia. The toads are toxic to some species of snakes, such as Dendrelaphis punctulatus. The longer an individual snake is, the greater its chance of survival after eating a cane toad. Which of the following did scientists most likely observe in the D. punctulatussnake population as a result of the presence of the cane toads?

Accepted Answer

Since longer snakes have a greater chance of survival after eating a cane toad, over time, natural selection would favor these longer individuals. This would lead to an increase in the average body length within the D. punctulatus snake population as the longer snakes survive and reproduce, passing on their genes for longer body length.

Question 19

Which of the following is a body system response that adjusts body temperature when it is higher than normal?

Accepted Answer

Sweat glands produce and secrete sweat as a mechanism to cool the body down when the body temperature is higher than normal. The evaporation of sweat from the skin surface helps to lower body temperature.

Question 20

An inherited metabolic disorder called phenylketonuria (PKU) can result in serious problems in infancy. The chance that two parents who are heterozygous will have a child with PKU is 25%.Which of the following terms best applies to the inheritance pattern for PKU?

Accepted Answer

PKU is inherited in an autosomal recessive manner, meaning that a child must inherit two copies of the faulty gene (one from each parent) to exhibit the disease. Parents who are heterozygous (carriers) have a 25% chance of having a child with PKU if both pass on the recessive allele.

Quiz 1: Biology