31) The DNA of a cell analyzed and found to : 1380810.
31) The DNA of a cell is analyzed and found to contain 28 percent thymine. What percent of the DNA would by cytosine?
A) 22 percent
B) 28 percent
C) 50 percent
D) 25 percent
32) The average mutation rate for DNA replication is 1 mutation for every 10 billion (10,000,000,000) nucleotides of DNA replicated. Yet DNA polymerase makes a mistake during replication at an average of 1 in 100,000 nucleotides. What does this say about DNA replication?
A) Most errors in DNA replication become mutations.
B) The base-pairing rules (A pairs with T and G pairs with C) prevent any mutations.
C) Cells are extraordinarily proficient at repairing errors made during DNA replication.
D) Cells recognize that a small fraction of mutations are beneficial to organisms and do not repair those.
33) Cancer is a disease caused by mutations. Yet in most instances if one of your parents tragically died from cancer, this does not put you at greater risk than a person whose parents do not develop cancer. How can cancer be caused by mutations and yet not be heritable?
A) The mutations that cause cancer are special and cannot be passed on regardless of what type of cell they occur in.
B) Most cancers arise from mutations in germ-line cells.
C) Most cancers arise from mutations in somatic cells.
D) Cancer-causing mutations are repaired in offspring but not in parents.
34) On average, if you examine 1 million human cells looking at a single gene, you’ll find one cell with a mutation in that gene. If you were looking at a gene that could lead to cancer when mutated, how many mutated copies of that gene would you find in a person? (Assume a person contains 100 trillion [100,000,000,000,000] cells.)
35) Mutations that occur in somatic cells are:
A) responsible for the appearance of human diseases such as sickle-cell anemia.
B) never harmful.
C) passed on to successive generations when they are incorporated into gametes.
D) not passed on to future generations.
E) always harmful.
36) Melanoma is a cancer that is frequently associated with a mutation in what gene?
A) in the IT15 gene
B) in the DNA polymerase gene
C) in the BRAF gene
D) in the Huntington gene
37) What is a point mutation?
A) a mutation that affects a single cell
B) a mutation in which one chromosome is lost
C) an error in DNA that is caused by malfunctioning of DNA ligase
D) a mutation found at a single base pair in the genome
E) a mutation that affects only one metabolic pathway
38) Which type of mutation will have the most impact from an evolutionary point of view?
A) a mutation in a somatic cell
B) a mutation in a liver cell
C) a mutation in a germ-line cell
D) a mutation in a brain cell
39) How do most mutations affect an organism?
A) Most mutations either are harmful, or they have no effect.
B) Most mutations will kill the organism.
C) Most mutations create cancerous cells.
D) Most mutations are beneficial and create a more adapted organism.
40) Which process changes, adds, or removes information from the genome?
B) DNA replication
C) genetic recombination
D) crossing over