Chapter 9, Problem 35A

Summary Introduction

Introduction:

Stem cells are unspecialized cells that can undergo division and develop into specialized cells under the right conditions and with proper signals. These cells can specialize into various tissues, organs and organ system. They can remain in an organism for many years while undergoing cell division. There are two basic types of stem cells; embryonic stem cells and adult stem cells.

Answer to Problem 35A

Correct answer :

The correct answer is option B. There are ethical concerns about obtaining stem cells

Explanation of Solution

Explanation/justification for the correct answer:

Option B. There are ethical concerns about obtaining stem cells−Some stem cell researchers have experienced roadblocks in their studies because there are ethical concerns about the source of stem cells. Obtaining embryonic stem cells is controversial as consent of donor is not taken into account but obtaining adult stem cells is not that controversial as they can be obtained with the consent of the donor.

Hence this is the correct option.

Explanation for incorrect answer:

Option A. Stem cells cannot be found−Stem cells can be found in various tissues of the body like the embryo, nasal cavity, bone marrow etc. Hence this is not the correct option.

Option C. There are no known uses for stem cells- Stem cells have many uses. They have the potential to cure many genetic defects and medical conditions. Scientists have been able to cure paralysis by using stem cells from nasal cavity. Researchers have also been able to restore lost brain tissue in mice by using stem cells. Hence this is not the correct option.

Option D. Stem cells do not become specialized cells- Stem cells are unspecialized cells that can undergo division and develop into specialized cells under the right conditions and with proper signals. These cells can specialize into various tissues, organs and organ system.Hence this is not the correct option.