Question 1

A scientist is analyzing a sample of tissue from a plant. Which of the following elements will be most abundant in the sample?

Accepted Answer

Plants, like all living organisms, are primarily composed of carbon, hydrogen, and oxygen. These elements are fundamental to the structure of organic molecules, including carbohydrates, lipids, proteins, and nucleic acids, which constitute the bulk of plant tissue.

Question 2

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?

Accepted Answer

The production of light in the cells with the inserted luciferase gene indicates that the gene was successfully transcribed (converted into messenger RNA) and translated (converted into the luciferase enzyme), leading to the biochemical reaction that produces light.

Question 3

Which of the following statements best compares sensory neuron function and motor neuron function in the human body?

Accepted Answer

Sensory neurons transmit information from sensory receptors to the central nervous system (CNS), allowing the body to perceive stimuli. Motor neurons, on the other hand, carry commands from the CNS to muscles and glands, initiating responses or actions.

Question 4

Which of the following statements explains why viruses are able to reproduce only inside host cells instead of being able to reproduce on their own?

Accepted Answer

Viruses lack the necessary cellular components, such as ribosomes and enzymes, for replication. They rely on the host cell's machinery to replicate their genetic material and produce new virus particles.

Question 5

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

Accepted Answer

The presence of limb buds during embryonic development in some snake species suggests a genetic remnant from an evolutionary ancestor that had legs, providing direct evidence of evolutionary history.

Question 6

Baby food manufacturers sometimes use proteases in their products. Proteases catalyze the breakdown of the proteins in these foods, making digestion easier for infants. Proteases are which of the following types of molecules?

Accepted Answer

Proteases are enzymes that catalyze the breakdown of proteins into smaller peptides or amino acids, facilitating easier digestion.

Question 7

Shelly and Jason are siblings, but Shelly looks like their father while Jason looks like their mother. Which of the following statements best explains the difference in Shelly's and Jason's features?

Accepted Answer

Shelly and Jason inherited different combinations of 23 chromosomes from their mother and 23 chromosomes from their father, which explains the variation in their features. Each sibling gets a unique mix of genes, leading to differences in appearance.

Question 8

High levels of carbon dioxide in the blood trigger which of the following responses in the body?

Accepted Answer

High levels of carbon dioxide in the blood signal the brain to increase the rate of breathing to expel the excess CO2 and take in more oxygen, helping to maintain the body's pH balance.

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

The decrease in nitrogen compounds in the first plot can be best explained by the fact that plants absorb nitrogen compounds from the soil for their growth. This is a fundamental aspect of plant nutrition, where nitrogen is a key nutrient required for the synthesis of proteins and other vital components.

Question 10

In a population of moths, wing color became darker over time. Which of the following is the best evidence that the change in wing color was an evolutionary change?

Accepted Answer

The change in allele frequencies in a population over time is the definition of evolution. Therefore, if the frequencies of alleles for dark wing color in the moth population changed, this is direct evidence of an evolutionary change.

Question 11

Leaves fall from deciduous trees in autumn. The carbon in these leaves is returned to the atmosphere through which of the following processes?

Accepted Answer

Decomposition of leaves by microorganisms releases carbon dioxide back into the atmosphere as part of the carbon cycle.

Question 12

Which of the following statements best explains why geographic isolation can lead to speciation?

Accepted Answer

Physical separation of populations prevents interbreeding and mixing of gene pools, which can lead to the development of distinct species as each isolated population adapts to its specific environment and evolves independently.

Question 13

Emphysema is a severe respiratory system disease. The disease causes damage that directly prevents the transfer of oxygen to the bloodstream.Which part of the respiratory system does emphysema damage?

Accepted Answer

Emphysema primarily damages the alveoli, which are the tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs. This damage impairs the lungs' ability to oxygenate blood effectively.

Question 14

Which of the following provides the most conclusive evidence that organisms of two different species share a common ancestor?

Accepted Answer

Similar DNA sequences between organisms of two different species are the most conclusive evidence of a common ancestor, as DNA is the fundamental molecule of life that carries genetic information from one generation to the next. Similarities in DNA sequences suggest a shared lineage and evolutionary history.

Question 15

In a certain variety of chicken, some offspring have a feather pattern that is black-and-white checkered. Chickens with this checkered feather pattern result from the cross of a black chicken with a white chicken.Which of the following types of inheritance is most likely responsible for the checkered feather pattern?

Accepted Answer

Codominance is the most likely type of inheritance responsible for the checkered feather pattern, as it involves the expression of both alleles (in this case, black and white) in the phenotype, resulting in a mixed or checkered appearance.

Question 16

Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin?

Accepted Answer

Ovalbumin, like all proteins, is made up of a chain of amino acids that are folded and twisted into a specific three-dimensional structure. This structure is crucial for its function.

Question 17

Blue jays and kingbirds are both classified in the order Passeriformes. In the current taxonomic system, this means that the two types of birds must also belong to the same

Accepted Answer

In the current taxonomic system, the order Passeriformes is a classification that is broader than family or genus, but more specific than class and phylum. Since both blue jays and kingbirds are classified in the order Passeriformes, they must share the same phylum, which is Chordata, the phylum that includes all vertebrates. The options of family, genus, and species represent increasingly specific levels of classification, none of which are necessarily shared between blue jays and kingbirds simply because they are both in the order Passeriformes.

Question 18

Which of the following processes releases primarily oxygen into the atmosphere?

Accepted Answer

Photosynthesis is the process by which plants, algae, and some bacteria convert carbon dioxide and water into organic matter, using sunlight as energy, and release oxygen as a byproduct.

Question 19

A tomato plant in a greenhouse was found to be infected with tobacco mosaic virus. A few weeks later, nearby plants were alsofound to be infected with the virus. Which of the following best describes how the virus reproduced?

Accepted Answer

Viruses, including the tobacco mosaic virus, cannot reproduce on their own and do not produce spores or seeds. Instead, they rely on the host cell's machinery and resources to replicate. They inject their genetic material into the host cell, which then uses that material to produce more virus particles.

Question 20

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

Elm trees with resistance genes are more likely to survive the fungal infection and reproduce, passing on their resistance genes to their offspring. This is a classic example of natural selection, where individuals with advantageous traits are more likely to survive and reproduce.

Quiz 1: Biology