Biology Diagnostic (2025)

Scientists are studying a drug to see how effective it is at reducing the production of usable energy in cells. What should the scientists measure to determine whether the drug is effective?

• the amount of ATP in cells

• the amount of RNA in cells

• the number of new cells produced by old cells

• the number of nerve signals produced by cells

Kudzu is an invasive plant that can grow as much as one foot in a day. A partial food web for an ecosystem is shown. Suppose kudzu invades this ecosystem. Select three organisms that would most likely compete with kudzu in this ecosystem.

• coyote

• wildflower

• oak tree

• butterfly

• grass

The (a)   nucleotides in the mRNA transcript should be replaced with ​ (b)   nucleotides.

• Adenine
• Guanine
• uracil
• cytosine

Based on the energy pyramid, how much energy would be stored in the tertiary consumers in this ecosystem?

• 2,000 kcal

• 200 kcal

• 20 kcal

• 2 kcal

Select two factors that are responsible for the inefficiency of energy transfer from one trophic level to another.

• Carnivores obtain energy from consumers only.

• Organisms lose energy to the environment as heat.

• Some parts of organisms are not eaten by consumers.

• Omnivores get energy from producers and consumers.

Which of the following best explains why bacteria are able to adapt to changing environmental conditions?

• A. Bacteria have DNA that rarely mutates in the population.

• B. Bacteria reproduce rapidly, allowing mutations to increase in the population.

• C. Bacteria reproduce asexually, causing little genetic variation in the population.

• D. Bacteria exchange genetic material, which increases the number of chromosomes in the population.

A Siamese cat has both dark and light fur on its body, as shown. The production of the protein that determines fur color is dependent upon temperature. The fur on the body of the cat is lighter colored because its body is warmer than its head, feet, and tail. Which of the following best describes how fur color is determined in a Siamese cat?

• Fur color is determined only by genes and RNA sequences that code for temperature.

• Fur color is determined by proteins from the environment and the temperature of the genes.

• Fur color is determined by a gene that codes for a protein and by the temperature of the environment.

• Fur color is determined only by environmental factors that include genes and the temperature of the cat.

Some mammals do not have enamel on their teeth, but they have copies of a gene that helps regulate enamel formation. The gene is mutated so that enamel is not produced. Which of the following best explains why these mammals have copies of a gene that codes for enamel?

• These mammals are going to evolve to have extra copies of the gene in the future.

• These mammals might need to repair the gene and produce enamel if their current diet changes.

• These mammals would be in danger of becoming extinct without high gene diversity in their populations.

• These mammals are descended from mammals with enamel on their teeth and functional copies of the gene.

A scientist wants to produce a single strand of DNA that codes for this amino acid chain. How many nucleotides will be in the DNA that the scientist produces?

• 5 nucleotides

• 6 nucleotides

• 12 nucleotides

• 18 nucleotides

A scientist is studying the stages of meiosis in a cell that has two pairs of chromosomes. The diagram shows a parent cell and four daughter cells formed after meiosis. Which of the following best explains what occurred in this parent cell?

• Abnormal meiosis occurred because half of the daughter cells are haploid and half of the daughter cells are diploid.

• Abnormal meiosis occurred because some daughter cells received more chromosomes than the other daughter cells.

• Normal meiosis occurred because some daughter cells received more dominant genes than the other daughter cells.

• Normal meiosis occurred because half of the daughter cells became egg cells and half of the daughter cells became sperm cells.