Every 24 Hours, Every Genome in Every Cell of the Human

question 20

Multiple Choice

Every 24 hours, every genome in every cell of the human body is damaged 10,000 times or more. Given the possible DNA repair mechanisms, which order listed below would be most effective at repairing these as quickly as possible in order to prevent mutations from being carried forward in DNA replication?

• A) proofreading by DNA polymerase, glycosylase enzyme activities, excision repair, photoreactivation, SOS repair
• B) SOS repair, photoreactivation, excision repair, glycosylase enzyme activities, proofreading by DNA polymerase
• C) photoreactivation, SOS repair, proofreading by DNA polymerase, glycosylase enzyme activities, excision repair
• D) glycosylase enzyme activities, SOS repair, photoreactivation, proofreading by DNA polymerase, excision repair

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Definitions:

Genotype

The genetic makeup of an organism, determining inherited characteristics.

Phenotype

The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Sympathetic

Characterized by feelings of compassion or understanding towards the situations of others.

Nervous System

The body’s communication network that utilizes neural cells to transmit information, coordinating voluntary and involuntary actions and transmitting signals between different parts of the body.