Chapter 17, Problem 1Q

Summary Introduction

(a)

To Determine:

If the given statement is true or false.

Introduction:

Cancer is a disease caused due to the metastasis of tumor cells to different parts of the body. It can occur due to a mutation in tumor suppressor gene and proto-oncogenes, viruses, radiation and carcinogens.

Answer to Problem 1Q

The given statement is true.

Explanation of Solution

Old people are more susceptible to disease such as cancer due to reduced immunity and accumulation of mutations over time. A few mutations might not cause any issue, however the accumulation of these mutations as one grows old leads to cancer.

Summary Introduction

(b)

To Determine:

If the given statement is true or false should be determined.

Introduction:

Industrialized societies with better health facilities due to advancement in the field of science and technology have higher life expectancies. It also means that there is more time for the damages caused in the cells due to mutations to accumulate and eventually disturb the cell cycle.

Answer to Problem 1Q

The statement is true.

Explanation of Solution

The rate of cancer are higher in industrialized societies that have longer life expectancies. Longer age leads to accumulation of more mutations that have a higher chance of disturbing the cell cycle. An unregulated cell cycle due to these changes in the cells leads to higher cases of cancer in such societies.

Summary Introduction

(c)

To Determine:

If the given statement is true or false should be determined.

Introduction:

Cancer can arise due to a variety of factors. These factors include exposure to radiation, carcinogens, accumulation of random mutations, infection by cancer-causing viruses, hormonal imbalance, and obesity.

Answer to Problem 1Q

The statement is false.

Explanation of Solution

A single mutation usually does not abolishes the entire control of the cell cycle as it is regulated at various levels. Cancer is caused due to the accumulation of such mutations that disturb the cell cycle regulation at multiple levels.

Summary Introduction

(d)

To Determine:

If the given statement is true or false should be determined.

Introduction:

The immune system plays an important role in protecting the body from any foreign antigen. The cancer cells project some different set of proteins on their membrane, which can be identified by the immune system leading to their elimination.

Answer to Problem 1Q

The statement is true.

Explanation of Solution

The cancer cells are eliminated by the dendritic cells of the immune system much like the virus elimination. The dendritic cells has the ability to present the proteins of the cancer to the T-cells, which then produce cytokines to activate various immune response for the elimination of affected cells.

Summary Introduction

(e)

To Determine:

If the given statement is true or false should be determined.

Introduction:

Remission is a case wherein the cancer case completely gone and a partial remission means that the patient can pause the treatment for some time, however, there are chances for cancer to bounce back.

Answer to Problem 1Q

The statement is false.

Explanation of Solution

Most of the cancers have a chance of bouncing back as soon as the treatment is stopped. This can occur due to the survival of some cancer cells during the treatment. The cells are very small and are spread across the body due to metastasis that they might miss the eye of a doctor.

Summary Introduction

(f)

To Determine:

If the given statement is true or false should be determined.

Introduction:

Proto-oncogenes encode for a protein that regulated the cell cycle. Mutation in these genes leads to the formation of oncogenes that can cause the disturbance in the cycle, eventually leading to cancer.

Answer to Problem 1Q

The statement is false.

Explanation of Solution

Cancer can be caused due to a variety of factors including inheritance, smoking, tobacco, obesity, hormonal imbalance, and viruses. Although viruses are one of the causes of cancer, they are not the number one cause of cancer.

Summary Introduction

(g)

To Determine:

If the given statement is true or false should be determined.

Introduction:

Immunosuppressant reduces the capacity of the body to fight infections by suppressing the immune cells. This paves the way for infections and mutations without getting noticed by the body which increases the risk of cancer.

Answer to Problem 1Q

The statement is true.

Explanation of Solution

Immunosuppressant reduces the ability of the body to fight infections and notice any mutated cells. Usually, the mutated cells are eliminated by the immune cells as the mutated proteins are recognized by these cells presented by major histocompatibility complexes on their membranes. If their activity of reduced these cells keeps accumulating mutations increasing the risk of cancer.