Question 1

The mitotic stage of cell division consists of

Accepted Answer

The mitotic stage of cell division consists of two main processes: mitosis and cytokinesis. Mitosis is the process of dividing the nucleus into two identical daughter nuclei, while cytokinesis is the process of dividing the cytoplasm to create two separate daughter cells. Option A is incorrect as DNA degradation does not occur in mitosis. Option C is incorrect as duplication and division are two separate processes that occur during different stages of the cell cycle. Option D is incorrect as cell growth and cell death are not specific to the mitotic stage. Option E is incorrect as meiosis is a different form of cell division that occurs in sexually reproducing organisms.

Question 2

Following a cut or scrape, which process repairs your skin?

Accepted Answer

Mitosis is the process responsible for repairing skin after a cut or scrape. Mitosis is the process in which cells divide and create two identical daughter cells. This allows for new cells to be produced to replace the damaged or lost cells in the skin. Meiosis is the process in which cells divide to create sex cells and apoptosis is the process of programmed cell death.

Question 3

Which of the following proteins would you expect to be a coded for by a proto-oncogene?

Accepted Answer

Proto-oncogenes normally code for proteins involved in cell growth and division regulation, such as growth factor receptors. A DNA repair protein (B) or a protein involved with the checkpoint for DNA damage (C) are typically encoded by tumor suppressor genes, which prevent cells from proliferating when damaged. Similarly, enzymes involved with apoptosis (D) are often encoded by tumor suppressor genes to induce programmed cell death in cells that can't be repaired. A DNA replication protein (E) is simply involved in the process of DNA synthesis and is not typically associated with the regulation of cell growth and division.

Question 4

Upon examination, a cell is found to have twice as much DNA as the normal diploid state but is no longer in the process of replicating the DNA. All of the DNA is found within a single nucleus. Which phase of the cell cycle is this cell in?

Accepted Answer

This cell is in the G2 phase of the cell cycle, which occurs after DNA replication but before mitosis (M phase). The fact that the cell has twice as much DNA as normal diploid cells indicates that it has undergone DNA replication, which occurs during the S phase. Therefore, the cell must be in either the G2 phase or M phase. Since the question states that the cell is not in the process of replicating DNA, it cannot be in the S phase. Furthermore, cytokinesis is the stage that follows mitosis, so it cannot be the answer either. Therefore, the correct answer is D, which represents the G2 phase.

Question 5

Technically, mitosis refers to nuclear division and not cytoplasmic division.

Accepted Answer

Mitosis is the process of nuclear division, where the replicated DNA is divided equally into two daughter nuclei. Cytoplasmic division is a separate process called cytokinesis, which follows mitosis and involves the division of the cytoplasm and the formation of two daughter cells.

Question 6

Which type of genes, when abnormally activated, can result in cancer?

Accepted Answer

Proto-oncogenes are normal genes that can become oncogenes when they are mutated or abnormally activated. Oncogenes promote cell growth and division, and when their activity is uncontrollably increased, they can lead to the development of cancer. Tumor suppressor genes, on the other hand, normally prevent cancer development by regulating cell growth and division, and mutations that inactivate tumor suppressor genes can also lead to cancer. However, the question specifically asks about genes that are abnormally activated, which is characteristic of proto-oncogenes. Apoptosis initiator and executioner genes regulate programmed cell death, which plays a role in cancer, but their abnormal activation is not directly linked to cancer development. DNA repair protein genes are involved in maintaining the integrity of the genome, and mutations in these genes can increase the risk of developing cancer, but their abnormal activation is not usually associated with cancer.

Question 7

Proteins that promote the cell cycle and prevent apoptosis are encoded by

Accepted Answer

Proto-oncogenes encode proteins that promote the cell cycle and prevent apoptosis, playing a role in cell growth and division.

Question 8

The cell cycle consists of

Accepted Answer

The cell cycle consists of two main stages: interphase and mitosis. Interphase is the period of growth and replication of cellular components, while mitosis is the division of the cell's genetic material and subsequent separation of the cell's cytoplasmic components. Therefore, choice A is the correct answer as it includes both mitosis and interphase.

Question 9

During which stage of the cell cycle do the chromosomes duplicate?

Accepted Answer

Chromosomes duplicate during the S phase of interphase.

Question 10

Growth factors that are transported through the blood play what role in the cell cycle?

Accepted Answer

Growth factors that are transported through the blood act as external signals to tell the cell whether or not to divide. They can promote cell division by triggering the cell to enter the cell cycle and progress through it.

Question 11

Which of the following is the correct sequence for the cell cycle?

Accepted Answer

The correct sequence for the cell cycle is G1-S-G2-M, which corresponds to the choice that starts with "G" (for G1 phase), followed by "S" (for Synthesis phase), then "G" (for G2 phase), and finally "M" (for Mitosis phase).

Question 12

When does apoptosis occur?

Accepted Answer

Apoptosis is programmed cell death and occurs during development to ensure proper formation of tissues and organs.

Question 13

Which of the following proteins would you expect to be a coded for by a proto-oncogene?

Accepted Answer

Proto-oncogenes are genes that play a role in cell division and differentiation. They can become oncogenes when they undergo mutations that lead to overexpression or constitutive activation. Growth factor receptors are proteins that bind to growth factors and help regulate cell growth and division, making them a likely target for proto-oncogene mutation.

Question 14

During interphase

Accepted Answer

During interphase, the cell is in a period of growth and preparation for cell division. One of the key processes during interphase is DNA replication, where the hereditary material (chromosomes) duplicates itself to ensure that each daughter cell will receive a complete set of genetic instructions during cell division. Options A, B, C, and D are not accurate descriptions of interphase.

Question 15

The only function of apoptosis is to destroy healthy cells when they become damaged or infected.

Accepted Answer

While apoptosis does play a role in eliminating damaged or infected cells, it also has other functions such as regulating tissue development and eliminating cells during normal physiological processes such as embryonic development and hormone-dependent involution of organs.

Question 16

Which of the following correctly describes apoptosis?

Accepted Answer

Apoptosis is the process of programmed cell death. One of the characteristic features of apoptosis is the fragmentation of the nucleus, which is caused by the activation of enzymes called caspases that break down the nuclear DNA. The other choices do not accurately describe apoptosis.

Question 17

If a cell stops at the G₁checkpoint, this is most likely due to what problem?

Accepted Answer

The G1 checkpoint ensures that the cell's DNA is intact and undamaged before proceeding to DNA replication. If there is DNA damage, the cell will stop at this checkpoint to allow for repair.

Question 18

Which of the following best characterizes apoptosis?

Accepted Answer

Apoptosis plays a normal role in development and cancer prevention. Unlike necrosis, which is accidental cell death from injury or disease, apoptosis is a programmed cell death that occurs in response to signals from the cell or its environment. Apoptosis plays a normal role in development by removing unneeded cells and shaping tissues and organs. It also plays a role in preventing cancer by eliminating cells with DNA damage or other abnormalities. Therefore, apoptosis is not bad for an organism, the stages of apoptosis are generally similar across cell types, and it is not accidental. While apoptosis is involved in the transition from a fertilized egg to trillions of cells, this statement alone does not best characterize apoptosis.

Question 19

Hormones that deliver a signal to the plasma membrane of target cells are known as

Accepted Answer

Growth factors are a type of hormone that bind to receptors on the plasma membrane of target cells to initiate a cellular response, often involved in cell growth and division.

Question 20

Which of the following is a correct association?

Accepted Answer

The G₂ stage is associated with the cell synthesizing proteins necessary for cell division, which is a key process during the cell cycle to ensure that the cell has all the components needed for division.

Quiz 5: Cell Division

The mitotic stage of cell division consists of

Following a cut or scrape, which process repairs your skin?

Which of the following proteins would you expect to be a coded for by a proto-oncogene?

Upon examination, a cell is found to have twice as much DNA as the normal diploid state but is no longer in the process of replicating the DNA. All of the DNA is found within a single nucleus. Which phase of the cell cycle is this cell in?

Technically, mitosis refers to nuclear division and not cytoplasmic division.

Which type of genes, when abnormally activated, can result in cancer?

Proteins that promote the cell cycle and prevent apoptosis are encoded by

The cell cycle consists of

During which stage of the cell cycle do the chromosomes duplicate?

Growth factors that are transported through the blood play what role in the cell cycle?

Which of the following is the correct sequence for the cell cycle?

When does apoptosis occur?

Which of the following proteins would you expect to be a coded for by a proto-oncogene?

During interphase

The only function of apoptosis is to destroy healthy cells when they become damaged or infected.

Which of the following correctly describes apoptosis?

If a cell stops at the G1 checkpoint, this is most likely due to what problem?

Which of the following best characterizes apoptosis?

Hormones that deliver a signal to the plasma membrane of target cells are known as

Which of the following is a correct association?

If a cell stops at the G₁checkpoint, this is most likely due to what problem?