Chapter 11, Problem 27A

Summary Introduction

Introduction: Chromosomes are the structures that contain the genetic material that are passed from generation to generation of cells. A chromosome consist of two identical sister chromatids. Sister chromatids are the structures that contain identical copies of DNA. The sister chromatids are attached at the center with a structure called centromere.

Answer to Problem 27A

Correct answer :

The correct answer is option B. They consist of DNA and sugars.

Explanation of Solution

Explanation/justification for the correct answer:

Option B. They consist of DNA and sugars- Chromosomes have protective caps called telomeres that consist of DNA associated with proteins. They do not contain sugars. So this is not true of telomeres.

Hence this option is the correct option.

Explanation for incorrect answer:

Option A. They are found on the ends of chromosomes − The protective ends of the chromosome are called telomeres. They are found at the tip of the chromosome. This is true of telomeres; hence, this is not the correct option.

Option C. They protect chromosomes- The protective ends of the chromosome are called telomeres. The cap serves as a protective function for the structure of the chromosome. They protect the vital information in the DNA. This is true of telomeres; hence, this is not the correct option.

Option D. Replication is a problem in most cells- Telomeres help in replication of DNA. They protect the vital genes from being deleted as DNA strands shorten during replication. In the absence of telomeres, replication is a problem in most cells. Hence this is not the correct option.