Cell Cycle and DNA Review

Front

What is the correct order of the cell cycle phases?

Back

G1, S, G2, M

Answer explanation

The correct order of the cell cycle phases is G1 (cell growth), S (DNA synthesis), G2 (preparation for mitosis), and M (mitosis). Therefore, the right choice is G1, S, G2, M.

Front

What is DNA's structure shape?

Back

Double Helix

Answer explanation

DNA's structure is a Double Helix, consisting of two intertwined strands that coil around each other. This shape is crucial for its function in storing and transmitting genetic information.

Front

Which base pairs with Adenine (A) in DNA?

Back

Thymine (T)

Answer explanation

In DNA, Adenine (A) pairs with Thymine (T) through two hydrogen bonds, ensuring proper base pairing. Guanine (G) pairs with Cytosine (C), while Uracil (U) is found in RNA, not DNA.

Front

What is the main function of DNA polymerase? Options: Unzipping the DNA, Joining Okazaki fragments, Adding nucleotides, Forming replication fork

Back

Adding nucleotides

Answer explanation

The main function of DNA polymerase is adding nucleotides to the growing DNA strand during replication, ensuring accurate copying of genetic information. This is crucial for cell division and maintaining genetic integrity.

Front

What enzyme unzips DNA?

Back

Helicase

Answer explanation

Helicase is the enzyme that unwinds and separates the two strands of DNA during replication, effectively 'unzipping' the DNA helix. This is essential for the replication process to occur.

Front

In which phase does DNA replication occur?

Back

S

Answer explanation

DNA replication occurs during the S phase of the cell cycle, where the cell synthesizes a complete copy of its DNA, preparing for cell division.

Front

What is the purpose of checkpoints in the cell cycle?

Back

To repair DNA damage

Answer explanation

Checkpoints in the cell cycle serve to monitor and repair DNA damage, ensuring that cells do not proceed to division with errors. This is crucial for maintaining genetic integrity.

Front

What is a mutation?

Back

A mistake in DNA

Answer explanation

A mutation refers to a mistake in DNA that can lead to changes in the genetic information. It is not a new cell type, an organelle, or a phase of mitosis, making 'A mistake in DNA' the correct choice.

Front

What base does Cytosine (C) pair with in DNA?

Back

Guanine (G)

Answer explanation

Cytosine (C) pairs with Guanine (G) in DNA through three hydrogen bonds, ensuring proper base pairing. Adenine (A) pairs with Thymine (T), while Uracil (U) is found in RNA, not DNA.

Front

What happens if the G1 checkpoint fails?

Back

The cell might begin uncontrolled division

Answer explanation

If the G1 checkpoint fails, the cell may not properly assess DNA damage or growth signals, leading to uncontrolled division. This can result in cancerous growth, making 'the cell might begin uncontrolled division' the correct choice.