Question 1

In 2006, scientists discovered fossilized skeletons of an animal with several interesting features. Fossil evidence indicated that the animal not only had scales, fins, and gills, but also had lungs, a full set of ribs, and limb bones arranged to support the animal's weight. The illustration below shows what the animal, called Tiktaalik, probably looked like based on the fossil evidence.Which of the following statements best explains why the Tiktaalik fossils are an important piece of evidence for evolution?

Accepted Answer

The Tiktaalik fossils are significant because they represent a transitional form between aquatic fish and terrestrial vertebrates, showcasing evolutionary adaptations for life both in water and on land, such as lungs and limb structures capable of supporting weight.

Question 2

Which of the following matches a cell organelle with its function?

Accepted Answer

The nucleus is responsible for cell regulation, as it contains most of the cell's genetic material and controls gene expression and the replication of DNA during the cell cycle.

Question 3

Until recently, the myrtle warbler and the Audubon's warbler were thought to be separate species of birds because the males have very different appearances. Which of the following observations most likely led to the reclassification of these warblers as one species?

Accepted Answer

Interbreeding and producing fertile offspring is a key criterion for classifying organisms as belonging to the same species, according to the biological species concept.

Question 4

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

Natural selection favored different fur colors in the different habitats, allowing mice with fur colors that matched their environment to better evade predators and survive to reproduce.

Question 5

Salivary amylase breaks down which class of organic molecules?

Accepted Answer

Salivary amylase specifically breaks down carbohydrates, starting the process of digestion in the mouth by acting on starches and converting them into simpler sugars.

Question 6

Which of the following statements best describes an effect of pH on the functioning of salivary amylase?

Accepted Answer

Salivary amylase functions most effectively at a neutral pH, around 7, which is close to the natural pH of the human mouth.

Question 7

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

Fatty acids are primarily used in the body for storing energy. They are stored as triglycerides in fat cells and can be broken down to provide energy when needed.

Question 8

Female cattle that have white coats are crossed with male cattle that have red coats. Both male and female offspring have roan coats, which are coats with both red hairs and white hairs.Which of the following best describes the genetics of coat color in the cattle?

Accepted Answer

The presence of both red and white hairs in the offspring indicates that the alleles for red and white coat colors are codominant, meaning both alleles are expressed in the phenotype.

Question 9

An endangered species is most vulnerable to extinction when it has which of the following characteristics?

Accepted Answer

A small amount of genetic diversity makes a species more vulnerable to extinction because it reduces the population's ability to adapt to changing environmental conditions and resist diseases.

Question 10

The amount of water a plant has in its tissues is determined primarily by the balance of which of the following processes?

Accepted Answer

The amount of water in a plant's tissues is primarily determined by the balance between root absorption, where the plant takes in water from the soil, and transpiration, where water is lost from the plant mainly through its leaves.

Question 11

Which type of cell must contain a mutation in order for the mutation to be passed from a woman to her offspring?

Accepted Answer

Mutations must occur in the germ cells (sperm or egg cells) to be passed from a parent to their offspring. In women, the relevant germ cells are the egg cells. Mutations in somatic cells (like blood, brain, or skin cells) are not hereditary.

Question 12

In tomato plants, the tall vine allele (T) is dominant to the short vine allele (t). Two tomato plants are crossed. Among the offspring plants grown from seed, 45% have tall vines and 55% have short vines.What are the most likely genotypes of the parent plants?

Accepted Answer

Given the offspring distribution, the most likely genotypes for the parents are Tt and tt. This cross would produce approximately 50% Tt (tall) and 50% tt (short) offspring, closely matching the observed 45% tall and 55% short.

Question 13

Degenerative nerve diseases destroy nerve cells. These diseases can lead to paralysis by interfering with which of the following?

Accepted Answer

Degenerative nerve diseases primarily affect the transmission of electrochemical signals from the brain to muscle cells, leading to issues such as paralysis. This is because the nerve cells (neurons) are responsible for carrying these signals, and their destruction disrupts this crucial communication pathway.

Question 14

In fish of the species Perissodus microlepis, some individuals have mouths that open to the right and some individuals have mouths that open to the left. The direction of the mouth opening is a genetic trait controlled by a single gene. The allele for a right-opening mouth (R) is dominant to the allele for a left-opening mouth (r). If two fish heterozygous for the mouth trait are crossed, what is the expected ratio of phenotypes in the offspring?

Accepted Answer

When two heterozygous individuals (Rr) are crossed, the expected genotype ratio is 1:2:1 (RR:Rr:rr), which translates to a phenotype ratio of 3 right-opening mouths (RR and Rr) to 1 left-opening mouth (rr), since the right-opening mouth allele (R) is dominant over the left-opening mouth allele (r).

Question 15

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

Accepted Answer

The kidneys filter blood to remove waste products and excess substances, which are excreted as urine. The liver also plays a crucial role in detoxifying blood, breaking down old or damaged blood cells, and metabolizing drugs and waste products. Both organs thus help in removing wastes from the blood, maintaining the cleanliness and proper chemical composition of the circulatory system.

Question 16

Garden pea plants can have yellow seeds or green seeds. In a pea plant that is heterozygous for seed color, the allele for yellow seeds masks the effects of the allele for green seeds.Which of the following terms best describes the allele for yellow seeds?

Accepted Answer

The allele for yellow seeds is described as dominant because it masks the effects of the allele for green seeds, meaning the yellow seed trait will be expressed in the phenotype of the heterozygous plant.

Question 17

The scientific name for the woodchuck is Marmota monax, and the scientific name for the long-tailed marmot is Marmota caudata. Which of the following statements describes the taxonomic relationship between the woodchuck and the long-tailed marmot?

Accepted Answer

Both the woodchuck (Marmota monax) and the long-tailed marmot (Marmota caudata) share the genus name "Marmota," indicating they belong to the same genus.

Question 18

Which of the following is incapable of reproducing outside a host cell?

Accepted Answer

Viruses are incapable of reproducing outside a host cell because they lack the necessary cellular machinery for replication and must hijack a host cell's machinery to reproduce.

Question 19

Which of the following statements describes the role of ATP in animal cells?

Accepted Answer

ATP (adenosine triphosphate) is the primary energy carrier in cells. It stores energy when it is not needed and releases it to fuel cellular processes.

Question 20

The bones that make up the forelimbs of monkeys, cats, whales, and birds are similar. Which of the following statements best supports the evolutionary relationship of these animals?

Accepted Answer

The similarity in the bone structure of the forelimbs across these diverse species suggests they share a common ancestor. Over time, evolutionary pressures have led to adaptations in these limbs for different environments and functions, supporting the concept of divergent evolution.

Quiz 1: Biology