Cell Cycle and DNA Review

What is the correct order of the cell cycle phases?

• G1, S, G2, M

• G2, S, G1, M

• M, G1, S, G2

• S1, G1, 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.

What is DNA's structure shape?

• Single Helix

• Double Helix

• Triple Helix

• Quadruple 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.

Which base pairs with Adenine (A) in DNA?

• Guanine (G)

• Cytosine (C)

• Thymine (T)

• Uracil (U)

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.

What is the main function of DNA polymerase?

• Unzipping the DNA

• Joining Okazaki fragments

• Adding nucleotides

• Forming replication fork

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.

What enzyme unzips DNA?

• Helicase

• DNA Ligase

• Primase

• DNA Polymerase

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.

In which phase does DNA replication occur?

• G1

• Mitosis

• S

• G2

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.

What is the purpose of checkpoints in the cell cycle?

• To speed up cell division

• To repair DNA damage

• To synthesize proteins

• To remove DNA errors

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.

Tags

NGSS.HS-LS1-4

What is a mutation?

• A new cell type

• A mistake in DNA

• An organelle

• A phase of mitosis

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.

Tags

NGSS.HS-LS3-2

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

• Adenine (A)

• Guanine (G)

• Thymine (T)

• Uracil (U)

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.

What happens if the G1 checkpoint fails?

• The cell will halt all activities

• The cell might begin uncontrolled division

• DNA replication will stop

• The cell will not complete cytokinesis

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.

Tags

NGSS.HS-LS1-4