Question: During DNA replication in a typical human cell,
Answer Options:
• A) only one origin of replication exists for each chromosome.
• B) multiple origins of replication function consecutively.
• C) multiple origins of replication function simultaneously.
• D) the origins of replication are at the centromeres.
• E) the origins of replication are at the telomeres.
Answer: C) multiple origins of replication function simultaneously.
Question: In mammalian cells, replication proceeds
Answer Options:
• A) unidirectionally
• B) bidirectionally.
• C) unidirectionally from many origins.
• D) bidirectionally from a single origin.
Answer: B) bidirectionally.
Question: Yeast research with autonomously replicating sequences (ARS), along with digestion of chromatin with DNase I, have led scientists to determine that
Answer Options:
• A) DNA is not protected inside a nucleosome.
• B) ARSs are really plasmids.
• C) ARSs bond irreversibly to replication enzymes.
• D) origins of replication are accessible regions of DNA devoid of nucleosomes.
Answer: D) origins of replication are accessible regions of DNA devoid of nucleosomes.
Question: In a typical human cell, DNA polymerase synthesizes DNA at a rate of approximately 50 nucleotides per second. Human chromosome 1 contains about 250 million base pairs. If a single origin of replication were used, how long would it take the cell to copy this chromosome?
Answer Options:
• A) less than 24 hours
• B) 1 to 2 days
• C) 1 to 2 weeks
• D) 50 to 60 days
• E) 110 to 120 days
Answer: D) 50 to 60 days
Question: Telomeres have at least two roles in chromosome integrity. Telomeres are composed of repeat sequences identical to the sequence of RNA in telomerase used for extending chromosome ends. Second, they
Answer Options:
• A) allow the chromosome to shorten each generation to speed up replication.
• B) interact with shelterin complexes that protect chromosome ends from degradation.
• C) permit the hairpin turn at the end to be cleaved.
• D) carry genes needed for DNA replication.
Answer: B) interact with shelterin complexes that protect chromosome ends from degradation.
Question: The two chromatids of each replicated chromosome must separate from one another and segregate during
Answer Options:
• A) mitosis.
• B) meiosis I.
• C) meiosis II.
• D) both mitosis and meiosis I.
• E) both mitosis and meiosis II.
Answer: E) both mitosis and meiosis II.
Question: In DNA, most satellite sequences are found in
Answer Options:
• A) chromosome arms.
• B) telomeres.
• C) centromeres.
• D) spaces around the dark bands.
Answer: C) centromeres.
Question: One of the functions of the centromere is to form a kinetochore for proper chromosome segregation. The other function is to
Answer Options:
• A) hold sister chromatids together.
• B) ensure that proper chromosome arm length is maintained.
• C) allow easy karyotyping.
• D) allow replication of chromosome ends.
Answer: A) hold sister chromatids together.
Question: Cohesins are multisubunit protein complexes that
Answer Options:
• A) hold sister chromatids together.
• B) ensure that proper chromosome arm length is maintained.
• C) allow easy karyotyping.
• D) allow replication of chromosome ends.
Answer: A) hold sister chromatids together.
Question: During mitosis, kinetochores assemble during
Answer Options:
• A) telophase.
• B) anaphase.
• C) metaphase.
• D) prophase.
Answer: D) prophase
Question: In yeast chromosomes, centromeres
Answer Options:
• A) help distinguish one chromosome from another.
• B) are closely related in sequence.
• C) are only 10–15 bp long.
• D) contain satellite DNA.
Answer: B) are closely related in sequence.
Question: In higher eukaryotes, kinetochores attach to
Answer Options:
• A) one spindle fiber.
• B) one spindle fiber on each side.
• C) multiple spindle fibers.
• D) multiple repeating structural subunits.
Answer: C) multiple spindle fibers.