IMAT - International Medical Admissions Cellular Biology and Division Questions and Answers

Question 1

A scientist is studying a cell that has just passed the G1 checkpoint. Which of the following processes is the cell now irreversibly committed to?

Accepted Answer

Replicating its DNA

Answer

The G1 checkpoint is a critical point in the cell cycle. Once a cell passes this checkpoint, it is committed to proceeding with cell division. The next phase after G1 is the S phase, where DNA synthesis or replication occurs. The other options are incorrect as protein synthesis for mitosis occurs later in G2, cytokinesis is the final stage of cell division, and entering G0 is a path taken by cells that do not pass the G1 checkpoint.

Question 2

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

Accepted Answer

Mitosis is involved in growth and repair, while meiosis produces gametes for sexual reproduction.

Answer

Mitosis is a process of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information; these cells are our sex cells – sperm in males, eggs in females. Crossing over is unique to meiosis I. Mitosis has one round of division, while meiosis has two.

Question 3

A new drug is developed that inhibits the function of the Golgi apparatus. A cell treated with this drug would be unable to properly perform which of the following functions?

Accepted Answer

Modifying, sorting, and packaging proteins and lipids

Answer

The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles. Lipid synthesis and detoxification occur in the smooth endoplasmic reticulum. ATP generation happens in the mitochondria. DNA replication occurs in the nucleus.

Question 4

During which phase of meiosis do homologous chromosomes separate and move to opposite poles of the cell?

Accepted Answer

Anaphase I

Answer

Anaphase I is the stage of meiosis where homologous chromosomes are pulled apart and move to opposite ends of the cell. In Anaphase II, it is the sister chromatids that separate. In Prophase I, homologous chromosomes pair up and crossing over occurs. In Metaphase II, chromosomes line up at the metaphase plate.

Question 5

A patient is diagnosed with a condition where their cells are unable to break down and recycle waste products, leading to an accumulation of cellular debris. This condition is most likely caused by a malfunction in which organelle?

Accepted Answer

Lysosomes

Answer

Lysosomes are membrane-bound organelles that contain digestive enzymes. They are involved in breaking down excess or worn-out cell parts, as well as destroying invading viruses and bacteria. Ribosomes are responsible for protein synthesis, mitochondria for energy production, and the nucleus contains the cell's genetic material.

IMAT - International Medical Admissions Test Practice Test

IMAT - International Medical Admissions Test Practice Test

IMAT - International Medical Admissions Cellular Biology and Division Questions and Answers