1) ) Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight because their cells have an impaired ability to
A) repair thymine dimers.
B) replicate DNA.
C) recombine homologous chromosomes during meiosis.
D) undergo mitosis
2) ) A eukaryotic cell lacking telomerase would
A) be unable to repair thymine dimers.
B) have a high probability of becoming cancerous.
C) be highly sensitive to sunlight.
D) produce Okazaki fragments.
E) undergo a reduction in chromosome length.
3) ) Which of the following statements about telomeres is correct?
A) They contain multiple copies of a short RNA sequence.
B) They can be extended by an enzyme called telomerase.
C) They are present at the ends of eukaryotic chromosomes.
D) both A and B
E) both B and C
Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because
A) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.
B) enzymes are made of DNA, and affected individuals lack DNA polymerase.
C) many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA.
D) certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors.
E) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes
4)
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