Question

1. what is the significance of genetic integrity during dna replication?

a. it ensures accurate transmission of genetic information
b. it allows for faster cell division
c. it enhances genetic diversity
d. it prevents mutations

1. what are the short sections formed on the lagging strand during dna replication called?

a. helicase fragments
b. polymerase fragments
c. leading fragments
d. okazaki fragments

1. how are okazaki fragments formed during dna replication?

a. by continuous synthesis of the leading strand
b. by synthesizing short segments on the lagging strand
c. by the action of ligase sealing gaps
d. by unwinding the dna double helix

Explanation:

Question 7

To determine the significance of genetic integrity during DNA replication, we analyze each option:

• Option a: Genetic integrity ensures that the genetic information (DNA sequence) is accurately copied and transmitted to daughter cells. This is crucial for maintaining the correct genetic code for cell function, development, and inheritance.
• Option b: Genetic integrity is not directly related to the speed of cell division. Cell division speed is regulated by other cellular mechanisms (e.g., cell cycle checkpoints, growth factors), not by the accuracy of DNA replication.
• Option c: Genetic integrity actually helps maintain the existing genetic information. Genetic diversity is mainly introduced by processes like mutation (which is what genetic integrity aims to minimize) and genetic recombination (e.g., in meiosis), not by DNA replication's integrity.
• Option d: While genetic integrity reduces the rate of mutations, it cannot completely prevent them. Mutations can still occur due to various factors (e.g., environmental mutagens, errors that escape repair mechanisms). The primary significance of genetic integrity is the accurate transmission of genetic information, and preventing mutations is a secondary effect (and not absolute).

So, the most accurate answer is option a.

During DNA replication, the lagging strand is synthesized discontinuously (because DNA polymerase can only add nucleotides in the 5' to 3' direction, and the lagging strand runs in the 3' to 5' direction relative to the replication fork movement). The short segments formed on the lagging strand are called Okazaki fragments.

• Option a: Helicase is an enzyme that unwinds the DNA double helix; it does not form fragments.
• Option b: DNA polymerase synthesizes the fragments, but they are not called "polymerase fragments."
• Option c: The leading strand is synthesized continuously, and there are no "leading fragments" (the leading strand is a continuous strand).
• Option d: This is the correct term for the short segments on the lagging strand.

To understand how Okazaki fragments are formed:

• Option a: The leading strand is synthesized continuously, and Okazaki fragments are not related to the leading strand's synthesis.
• Option b: The lagging strand is synthesized in short segments (Okazaki fragments) because DNA polymerase can only move in the 5' to 3' direction. As the replication fork opens, the lagging strand template is exposed in a direction that requires DNA polymerase to synthesize short segments (Okazaki fragments) that are later joined by ligase.
• Option c: Ligase seals the gaps between Okazaki fragments (joins them), but it does not form the Okazaki fragments.
• Option d: Helicase unwinds the DNA double helix, which is the first step in replication, but it does not form Okazaki fragments.

Answer:

a. It ensures accurate transmission of genetic information

Question 8