Chapter 11, Problem 1SQ

Your bore cells, muscle cells, and skin cells look different because

1. a. different kinds of genes are present in each kind of cell.
2. b. they are present in different organs.
3. c. different genes are active in each kind of cell.
4. d. different mutations have occurred in each kind of cell.

Summary Introduction

Introduction:

Almost all the cells in an organism are genetically identical. However, different cells are specialized to perform different roles through the differential gene expression process. Gene expression is regulated by turning on and off gene. Gene regulation is largely controlled by the binding of regulatory proteins to specific sites on DNA.

Answer to Problem 1SQ

Correct answer:

Eukaryotic and multicellular organisms regulate gene expression to maintain different cell types during embryonic development. Therefore, option c. is correct.

Explanation of Solution

Reason for the correct statement:

The gene regulation process facilitates the production of a specific set of protein. This process results in a different type of cells, such as skin cells, muscle cells, and bone cells.

Option c. is given as “different genes are active in each kind of cell”.

In eukaryotic organisms, each cell maintains differential gene expression. As the differential gene expression provides the cells with the expression of different proteins responsible for specific characters, different cell types (muscle, bone, and skin cells) look different.

Hence, option c. is correct.

Reasons for the incorrect statements:

Option a. is given as “different kinds of genes are present in each kind of cell”.

All the cells present in an organism contain identical genetic composition. Hence, it is a wrong answer.

Option b. is given as “they are present in different organ”.

Different cells enable different functions by organs through the expression of different genes. Organs are not responsible for cell diversity in the body. Hence, it is a wrong answer.

Option d. is given as “different mutations have occurred in each kind of cells”.

Mutation is responsible for altering the function of a gene present in the cell. However, it cannot be associated with the diversity of cells present in the organism’s whole body. Hence, it is a wrong answer.

Hence, options a., b., and d. are incorrect.

Conclusion

The bone cell, muscle cells, and skin cells look different due to the regulation of gene expression. Thereby, different kinds of proteins with different structures and functions are produced by each cell type.