MCAT – Biology Exam Questions and Answers

MCAT – Biology Exam Questions and Answers If we're looking at the brain from the top, what major part will we see (the most superficial part)? (A) Cerebrum (B) Midbrain (C) Medulla (D) Brain Stem - Correct Answer️️ -A The resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis. This is where the cell grows, but doesn't divide. - Correct Answer️️ -Interphase (most cells live here. The exception is cancer cells) Part of eukaryotic cell division during which the cell nucleus divides - Correct Answer️️ -Mitosis Describe the S phase. - Correct Answer️️ -The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. 28 pairs to 46 pairs. Describe the G1 phase - Correct Answer️️ -The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins. We make organelles and proteins here. A non-growing state distinct from interphase. Responsible for variations in length of the cell cycle between different types of cells. - Correct Answer️️ -Go Phase (Cell Growth and Division) Which phase of the cell cycle does the cell make microtubules? A. G1 B. S C. G2 D. M - Correct Answer️️ -C necessary for cell to enter Metaphase (Metaphase Promoting Factor) - Correct Answer️️ -CDK1/cyclin B What two cyclins bind to CDK4 and CDK2 in G1/S? - Correct Answer️️ -Cyclin D and Cyclin E (The CDK4/Cyclin D complex will phosphorylate Rb. By doing this, Rb can no longer inhibit DNA replication.) What protein is considered the "guardian of the genome"? - Correct Answer️️ -p53 (Blocks the progression of cell cycle when there is cancer.) What is the role of p21? - Correct Answer️️ -Inhibits CDKs p53 and Rb are considered what kind of genes? - Correct Answer️️ -Tumor suppressor genes The production, growth, and maturation of an egg, or ovum - Correct Answer️️ - Oogenesis Oogenesis, the process that creates female gametes, is halted at prophase I until puberty. Which of the following describes the DNA content of a female's gametes during her childhood? (Choice A) A 23 chromosomes, 46 chromatids (Choice B) B 23 chromosomes, 23 chromatids