Question 1

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",what did the researchers conclude from part b.of the figure?

Accepted Answer

The researchers concluded that the standard chemotherapy drug delayed the growth of tumors but resistance developed, as indicated in part b of the figure.

Question 2

A cell condenses its DNA into ______ in preparation for mitosis.

Accepted Answer

A cell condenses its DNA into chromosomes in preparation for mitosis. During mitosis, the replicated chromosomes separate and each daughter cell receives a copy of the genetic material.

Question 3

A replicated chromosome consists of two sister chromatids.

Accepted Answer

When a chromosome replicates, it produces two identical copies of itself that are attached to each other at a region called the centromere. These identical copies are called sister chromatids, and they make up a replicated chromosome.

Question 4

If one strand of a DNA molecule has the base sequence of 5' CGGCATTA 3' the complementary strand of DNA will read

Accepted Answer

The answer of If one strand of a DNA molecule...

Question 5

If a mutation causes the "T" base in the base sequence 5' AGTCCG 3' to be read as a "G" base,DNA replication of the mutated sequence will read

Accepted Answer

The answer of If a mutation causes the "T" base...

Question 6

When DNA replicates

Accepted Answer

During DNA replication, one strand of the original DNA serves as a template for the synthesis of a new complementary strand. As a result, one strand of the original DNA ends up in each of the new DNA molecules.

Question 7

Why don't plant cells form a cleavage furrow during cytokinesis?

Accepted Answer

Plant cells have a cell wall made of cellulose, which is rigid and cannot be bent. Therefore, instead of forming a cleavage furrow like in animal cells, plant cells form a cell plate that grows outward from the center of the dividing cell, eventually dividing the cell into two distinct daughter cells.

Question 8

Replication takes place during the G1 phase of interphase.

Accepted Answer

Replication takes place during the S phase of interphase, not G1.

Question 9

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",endostatin is a 184-amino acid protein that only affects endothelial cells.What is the best explanation for this observation?

Accepted Answer

Endothelial cells have a receptor on their cell membrane for endostatin, allowing the protein to specifically target and affect these cells.

Question 10

If a mutation causes the "G" base in the base sequence 5' AATGAC 3' to be read as a "T" base,DNA replication of the mutated sequence will read

Accepted Answer

If the "G" base is mutated to a "T" base, the new base sequence would be 5' AATTAC 3'. During DNA replication, the new complementary strand would be 3' TTAATG 5'. Therefore, the correct answer is D) 3' TTAATG 5'.

Question 11

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",what is the dependent variable in the figure?

Accepted Answer

The dependent variable in the figure is the volume of the tumor in mice. This is evident from the y-axis, which shows the tumor volume (in cubic millimeters) at different time points (in days). The different treatment groups (endostatin, chemotherapy, and control) are shown on the x-axis, but they are not the dependent variable being measured.

Question 12

Bypassing a checkpoint in the cell cycle may result in a cancer cell

Accepted Answer

Bypassing a checkpoint in the cell cycle may result in a cancer cell continuing to divide and replicate with faulty DNA. This can lead to further mutations and genetic instability, ultimately resulting in the formation of a tumor.

Question 13

Each newly replicated molecule of DNA contains one conserved strand from the original DNA molecule.

Accepted Answer

During DNA replication, one strand of the original DNA molecule acts as a template for the synthesis of a new complementary strand. The newly synthesized DNA molecule will contain one conserved (or unchanged) strand from the original DNA molecule.

Question 14

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",what hypothesis were the researchers testing by treating tumors with endostatin and the standard chemotherapy drug?

Accepted Answer

The researchers were testing the hypothesis that endostatin targets endothelial cells, which are part of the blood vessels supplying the tumor, and thus tumor cells would not develop resistance to it.

Question 15

During each round of replication,a mutation occurs in approximately 1% of a cell's nucleotides.

Accepted Answer

Mutations occur at a much lower rate than 1% per nucleotide during DNA replication, typically around 1 in 10 million to 1 in 100 million nucleotides.

Question 16

Any change in a cell's DNA sequence is a mutation.

Accepted Answer

Any alteration or change in the DNA sequence of a cell, no matter how small, is considered a mutation. Therefore, the statement "Any change in a cell's DNA sequence is a mutation" is true.

Question 17

During cytokinesis of a plant cell,the cell divides by forming a cleavage furrow.

Accepted Answer

In plant cells, a new cell wall forms between the two daughter cells during cytokinesis, making a cleavage furrow unnecessary. Instead, a structure called the cell plate forms at the center of the cell and gradually grows outward, dividing the cytoplasm and creating two new cells.

Question 18

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",the standard chemotherapy drug forms crosslinks between the two strands of DNA in a chromosome.How is this effective in chemotherapy?

Accepted Answer

Standard chemotherapy drugs that form crosslinks between the two DNA strands in a chromosome are effective because they delay DNA replication. This delay can lead to cell death, as cells rely on proper DNA replication in order to divide and function properly. By disrupting this process, the chemotherapy drugs can target rapidly dividing cancer cells and prevent them from spreading.

Question 19

In the section "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer",what did the researchers conclude from part a.of the figure?

Accepted Answer

The researchers concluded from part a. of the figure that Endostatin shrank tumors without development of resistance.

Question 20

The chemotherapy drug taxol inhibits microtubule function.A cell treated with taxol would become stuck in which phase?

Accepted Answer

After prophase, microtubules must form to align and then separate chromosomes.

Quiz 8: DNA Replication and Cell Division