Question 1

Which of the following best explains why plants appear green to the human eye?

Accepted Answer

Chlorophyll pigments absorb primarily purple/blue and red light, reflecting green wavelengths.

Question 2

A scientist inhibits the enzyme rubisco in a plant cell. Which of the following is the most immediate effect on photosynthesis?

Accepted Answer

ATP and NADPH will accumulate because the Calvin cycle cannot proceed.

Question 3

Which of the following statements about the electron flow in photosynthesis is correct?

Accepted Answer

Electrons from Photosystem II are transferred to Photosystem I, where they are used to reduce NADP$$^+ to $$NADPH.

Question 4

A plant is exposed to a herbicide that blocks the regeneration of NADP$$^+ in $$the chloroplast. What is the most likely consequence?

Accepted Answer

The light-capturing reactions will slow down because electrons cannot be transferred to NADP$$^+.$$

Question 5

Which of the following best describes the role of carotenoids in photosynthesis?

Accepted Answer

They act as antioxidants, neutralizing free radicals formed by high-energy light.

Question 6

A researcher uses CRISPR/Cas9 to target a gene in a mouse embryo but does not provide a homologous DNA template. What is the most likely outcome?

Accepted Answer

The targeted gene will likely be inactivated due to insertions or deletions during repair.

Question 7

Which of the following is a key difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two genetically identical cells, while meiosis produces four genetically diverse cells.

Question 8

A human cell with 47 chromosomes is most likely the result of which process?

Accepted Answer

Nondisjunction during meiosis, resulting in trisomy.

Question 9

Which of the following best explains why most aneuploidies involving large chromosomes result in embryonic death?

Accepted Answer

Large chromosomes contain more genes, so extra or missing copies disrupt more cellular processes.

Question 10

A woman who is heterozygous for a recessive allele (Aa) and a man who is homozygous dominant (AA) have a child. What is the probability that their child will be homozygous recessive (aa)?

Accepted Answer

$$0$$

Question 11

Which of the following is true regarding the function of tumor suppressor genes?

Accepted Answer

They normally inhibit cell growth and division; loss-of-function mutations can lead to cancer.

Question 12

Which of the following best describes the principle of segregation as it relates to Mendelian genetics?

Accepted Answer

Homologous chromosomes separate during meiosis, so each gamete receives only one allele for each gene.

Question 13

Which of the following scenarios would most likely result in photorespiration in a C3 plant?

Accepted Answer

High oxygen concentration in the leaf due to closed stomata during hot, dry conditions.

Question 14

Which of the following is a direct result of the electron transport chain in Photosystem II?

Accepted Answer

Formation of a proton gradient across the thylakoid membrane.

Question 15

A scientist wants to amplify a specific DNA sequence from a small blood sample. Which technique should they use?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 16

Which of the following is a unique feature of CAM plants compared to C3 and C4 plants?

Accepted Answer

They fix carbon dioxide at night and run the Calvin cycle during the day.

Question 17

Which of the following best explains why gene therapy often uses viral vectors?

Accepted Answer

Viruses can easily insert DNA into host cells due to their natural infection mechanisms.

Question 18

Which of the following events increases genetic diversity during meiosis?

Accepted Answer

Crossing over between homologous chromosomes during prophase I.

Question 19

A cell is observed to have a contractile ring forming a cleavage furrow during cytokinesis. This cell is most likely:

Accepted Answer

An animal cell undergoing mitosis.

Question 20

Which of the following best describes the function of restriction enzymes in DNA technology?

Accepted Answer

They cut DNA at specific nucleotide sequences, enabling the creation of recombinant DNA.

Midterm 3 Study Guide: Photosynthesis, DNA Technology, Cell Division, and Genetics

Study Guide - Practice Questions

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