Question: The enzyme that some eukaryotic organisms utilize for RNA-dependent DNA synthesis at the ends of linear chromosomes is called
Answer Options:
• A) DNA polymerase.
• B) telomerase.
• C) DNA ligase.
• D) replicase.
Answer: B) telomerase
Question: When a cell loses telomerase activity, what is the predicted effect?
Answer Options:
• A) Telomeres will increase slightly with each cell division.
• B) After 30–50 divisions, the cell will show signs of senescence and then die.
• C) An immune stem cell will increase white blood cell production.
• D) A normal somatic cell will gain the ability to divide indefinitely.
• E) The cell will die immediately.
Answer: B) After 30–50 divisions, the cell will show signs of senescence and then die.
Question: The components of a chromosome include one long DNA molecule and
Answer Options:
• A) phospholipids.
• B) proteins.
• C) carbohydrates.
• D) steroids.
• E) chromophores.
Answer: B) proteins
Question: By weight, chromatin consists roughly of
Answer Options:
• A) 1/3 DNA, 1/3 histones, and 1/3 nonhistones.
• B) 1/3 DNA and 2/3 acidic proteins.
• C) 1/2 DNA, 1/4 histones, and 1/4 basic proteins.
• D) 1/4 DNA, 1/4 RNA, 1/4 histones, and 1/4 nonhistones.
Answer: A) 1/3 DNA, 1/3 histones, and 1/3 nonhistones.
Question: Histones and DNA have a strong attraction for each other because
Answer Options:
• A) DNA is positively charged and histones are negatively charged.
• B) both DNA and proteins are hydrophobic.
• C) DNA is negatively charged and histones are positively charged.
• D) like substances share common charges.
Answer: C) DNA is negatively charged and histones are positively charged.
Question: Select the statement that correctly describes the roles of histone and nonhistone proteins found in chromatin?
Answer Options:
• A) Only histones have a structural role in chromatin.
• B) Only nonhistone proteins have a structural role in chromatin.
• C) Histone proteins function primarily in chromosome segregation.
• D) Both histone and nonhistone proteins have a structural role in chromatin.
• E) Nonhistone proteins function only in replication and chromosome segregation.
Answer: D) Both histone and nonhistone proteins have a structural role in chromatin.
Question: The first level of compaction of DNA consists of
Answer Options:
• A) DNA winding around histones to form nucleosomes.
• B) tight coiling of DNA with nucleosomes into higher order structures.
• C) compaction into metaphase chromosomes.
• D) histone, DNA, and nonhistone covalent bonding.
Answer: A) DNA winding around histones to form nucleosomes.
Question: The histone that appears to be responsible for organizing the 100 Å fibers into 300 Å fibers is
Answer Options:
• A) H4.
• B) H3.
• C) H2.
• D) H1.
Answer: D) H1
Question: In DNA, the 300 Å fiber is formed into structural loops. This function appears to be associated with
Answer Options:
• A) histone H4.
• B) nucleosomes.
• C) histone H1.
• D) certain nonhistone proteins.
• E) remodeling complexes.
Answer: D) certain nonhistone proteins
Question: In what stage of mitosis are the highly-compacted chromosomes used for FISH?
Answer Options:
• A) prophase
• B) metaphase
• C) anaphase
• D) telophase
• E) never achieves this level of compaction
Answer: B) metaphase
Question: The total compaction of DNA as seen in metaphase chromosomes is approximately ______-fold.
Answer Options:
• A) 10,000
• B) 50,000
• C) 100,000
• D) 40
Answer: A) 10,000
Question: A technique for visualizing mitotic chromosomes involves staining of chromosomes using Giemsa stain. At high resolution we see _______ of bands in a normal human diploid karyotype.
Answer Options:
• A) hundreds
• B) thousands
• C) millions
• D) billions
Answer: B) thousands