Chapter 7, Problem 27A

Summary Introduction

Introduction:

Plant and animal cells differ in the presence of cell wall. Cell walls provide rigidity and strength to cells. Cell walls are made of cellulose, a type of carbohydrate which gives the wall its inflexible feature. Cell wall is present in plant cells, fungi and some prokaryote cells.

Answer to Problem 27A

B. a cell from an oak tree

Explanation of Solution

Explanation/justification for the correct answer :

B. a cell from an oak tree- Cell wall is present in plant cells, fungi and some prokaryote cells. It is absent in animal cells. Cell wall is rigid thick mesh of fibers that surround the outside of plasma membrane. It provides strength to the cell wall. So, it can be found in the cells of an oak tree. Hence, this option is correct.

Explanation for incorrect answer :

A. a human skin cell- Human skin cells lack cell wall as cell wall is only found in plant cells and fungi. So, this is an incorrect option.

C. a blood cell from a cat- Blood cells of cat lack cell walls as cell wall is only found in plant cells and fungi. So, this is an incorrect option.

D. a liver cell from a mouse- Liver cells of a mouse lack cell walls as cell wall is only found in plant cells and fungi. So, this is an incorrect option.