Chapter 16, Problem 1TYU

Muscle cells differ from nerve cells mainly because they

1. A.    express different genes.
2. B.     contain different genes.
3. C.     use different genetic codes.
4. D.    have unique ribosomes.

Summary Introduction

Introduction:

Nerve cells and muscle cells are specialized and differentiated cells. They have their unique and specialized functions, structure, and characteristics. Nerve cells help in the transfer of electrical impulses through synapses, while muscle cells provide structure to the body and help in mobility.

Answer to Problem 1TYU

Correct answer:

The basic difference between nerve and muscle cell is their gene expression. Therefore, option (A) is correct.

Explanation of Solution

Reasons for the correct statement:

Cells become specialized only when they are able to express certain specific genes. If two cells express the same genes, their function would be the same and they would not be different from each other.

Option (A) is given as “express different genes”.

As “the muscle cells differ from nerve cells mainly because they express different genes”, it is the right answer.

Hence, option (A) is correct.

Reasons for the incorrect statements:

Option (B) is given as “contain different genes”.

All the cells in an individual contain same genes and same DNA (deoxyribonucleic acid). However, the difference arises due to the expression of genes. Muscle cells and nerve cells would also contain the same genes, but their gene expression would be different. So, it is a wrong answer.

Option (C) is given as “use different genetic codes”.

Genetic code is a process, by which the genetic information is translated into proteins. The genetic code is mostly similar among cells or organisms. So, it is a wrong answer.

Option (D) is given as “have unique ribosomes”.

Ribosomes are the same in every cell. All eukaryotic cells have 80s (s denotes a Svedberg’s unit) type ribosomes. Muscle and nerve cells would have the same 80s type ribosomes. So, it is a wrong answer.

Hence, options (B), (C), and (D) are incorrect.

Conclusion

The basic difference between any two specialized cells is their gene expression. Although, all the cells in an individual contain the same genes, but their expression makes them specialized.