Question 1

Which of the following best describes the difference between benign and malignant tumors?

Accepted Answer

Malignant tumors can metastasize to other parts of the body, while benign tumors remain localized.

Question 2

A patient inherits a mutated BRCA1 gene. What is the most direct consequence of this mutation at the cellular level?

Accepted Answer

Loss of tumor suppressor function, increasing the risk of unregulated cell division.

Question 3

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 4

Which of the following best explains why chemotherapy often causes hair loss and nausea?

Accepted Answer

Chemotherapy targets rapidly dividing cells, which include hair follicle and stomach lining cells.

Question 5

Which of the following equations correctly represents the chromosome number in human gametes after meiosis?

Accepted Answer

$$n = 23$$

Question 6

A cell with damaged DNA passes through the G1 checkpoint and continues to divide. Which of the following is the most likely explanation?

Accepted Answer

The cell has a mutated tumor suppressor gene that fails to halt the cell cycle.

Question 7

Which process during meiosis is primarily responsible for increasing genetic diversity among offspring?

Accepted Answer

Crossing over and random alignment of homologous chromosomes

Question 8

A researcher observes a cell with chromosomes aligned at the center of the cell, spindle fibers attached, and the nuclear membrane dissolved. Which stage of mitosis is this cell in?

Accepted Answer

Metaphase

Question 9

Which of the following best describes the structure of a DNA molecule?

Accepted Answer

A double-stranded helix with a sugar-phosphate backbone and nitrogenous bases paired by hydrogen bonds.

Question 10

If a cell undergoes mitosis but not cytokinesis, what is the result?

Accepted Answer

A single cell with two nuclei.

Question 11

Which of the following scenarios best illustrates the concept of synergistic risk factors for cancer?

Accepted Answer

A person who drinks alcohol and smokes tobacco has a much higher risk of cancer than either behavior alone.

Question 12

Which of the following best explains why radiation therapy is often used after surgical removal of a tumor?

Accepted Answer

Radiation therapy destroys any remaining cancer cells by damaging their DNA, reducing the risk of recurrence.

Question 13

During DNA replication, which enzyme is primarily responsible for adding new nucleotides to the growing DNA strand?

Accepted Answer

DNA polymerase

Question 14

A cell with 8 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 15

Which of the following events occurs during prophase I of meiosis but not during mitosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 16

A mutation converts a proto-oncogene into an oncogene. What is the most likely effect on the cell?

Accepted Answer

The cell will divide uncontrollably, increasing the risk of cancer.

Question 17

Which of the following best describes the outcome of nondisjunction during meiosis?

Accepted Answer

Some gametes have an abnormal number of chromosomes, leading to conditions such as trisomy 21.

Question 18

Which of the following is a direct result of random alignment of homologous chromosomes during meiosis I?

Accepted Answer

Each gamete receives a random mix of maternal and paternal chromosomes.

Question 19

Which of the following best explains why most human zygotes with an incorrect number of chromosomes do not develop to term?

Accepted Answer

The imbalance in chromosome number disrupts normal development, often leading to spontaneous abortion.

Question 20

Which of the following best describes the function of tumor suppressor proteins in the cell cycle?

Accepted Answer

They inspect newly replicated DNA and halt the cell cycle if damage is detected.

Cancer, DNA Synthesis, Mitosis, and Meiosis: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard