Cell Cycle Interactive

Match

Match these enzymes with their function in DNA replication: DNA polymerase, endonuclease, helicase, and ligase.

• Check the DNA for errors and attempt to correct them.

• Build new strands of nucleotides through complementary base pairing to the original strand.

• Break the hydrogen bonds holding two strand of nucleotides together.

• Attach nucleotides together within a strand by creating a covalent bond between the deoxyribose of one nucleotide and the phosphate group of the next nucleotide.

endonucleases

DNA polymerase

helicase

ligase

• endonucleases

• DNA polymerase

• helicase

• ligase

Multiple Choice

Use the models (A & B) to answer the following question. Which model and explanation BEST represents semiconservative replication?

• Model A because it shows one original strand and one complimentary strand in each product (F1) DNA molecule.

• Model A because none of the DNA molecules produced (F2) are identical to the parent DNA molecule.

• Model B because one F1 strand is identical to the parent molecule and the other is not.

• Model B because one of the F2 molecules contains the original strands of the parent molecule and the other three do not.

Multiple Choice

What are B?

• centrioles
• sister chromatids

• centromeres
• unreplicated chromosomes

Multiple Choice

Which of the following is considered DNA in its normal, unreplicated state?

• Chromatin

• Chromatids

• Centromere

• Chromosome

• Centriole

Multiple Choice

What is b in this image?

• replicated chromosome

• chromatid

• centromere

• chromatin

Multiple Choice

Which one is larger: chromatid or replicated chromosome?

• chromatid

• replicated chromosome

Multiple Choice

True or False: The DNA codes (nitrogen base sequence) on sister chromatids is identical.

• True

• False

Multiple Choice

True or False: The DNA codes (nitrogen base sequence) on homologous chromosomes is identical.

• True

• False

Multiple Choice

Before cells can divide, what must be copied?

• mitochondria
• cytoplasm
• DNA
• Cell Wall

Multiple Choice

When during the cell cycle does DNA replication occur?

• G1

• S

• G2

• At any time during the cycle

Multiple Choice

Which phase is metaphase?

• A

• B

• C

• D

Multiple Choice

What is the correct order for the phases of mitosis and cytokinesis?

• B, D, A, C

• C, A, B, D

• D, A, C, B

• A, C, D, A

Multiple Choice

In the G1 stage of the cell cycle, the cell

• Grows
• Matures
• Carries on normal activities
• All of the above

Multiple Choice

During which phase of the cell cycle does the cell spend the most time?

• Mitosis
• Cytokinesis
• Interphase

Multiple Choice

What phase of mitosis is occuring in the picture?

• Prophase
• Metaphase
• Anaphase

• Telophase

Multiple Choice

Name the phase:

• Prophase
• Metaphase
• Anaphase
• Telophase

Multiple Choice

What phase of mitosis is shown here?

• Prophase
• Metaphase
• Anaphase
• Telophase

Multiple Choice

If there are 20 chromosomes in the nucleus before mitosis how many will there be in each new daughter cell after cytokinesis?

• 10

• 20

• 40

• 200