Chapter 17, Problem 1Q

A.

Summary Introduction

To explain: Amoeba proteus (a free-living amoeba) contains a high density of intermediate filaments in its cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: It does not contain a high density of intermediate filaments in its cytoplasm.

Explanation of Solution

Amoeba proteus has moderate amount of intermediate filaments in their cytoplasm because this organism is a highly motile organism.

B.

Summary Introduction

To explain: Skin epithelium cell contains a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: It contains a high density of intermediate filaments in their cytoplasm.

Explanation of Solution

Skin epithelium cell such as keratin is composed of intermediate filament protein. It prevents the epithelial cell from rupturing when they are under heavy mechanical stress due to the movements of their tissues.

C.

Summary Introduction

To explain: Smooth muscle cell in the digestive tract contains a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: It contains a high density of intermediate filaments in their cytoplasm.

Explanation of Solution

During the muscle contraction, sarcomeres are stabilized by the desmin filaments, which are type-III intermediate filaments. Intermediate filaments also resist the muscle cell from mechanical stress.

D.

Summary Introduction

To explain: Escherichia coli species contain a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer:  It does not contain a high density of intermediate filaments in their cytoplasm.

Explanation of Solution

In the bacteria such as Escherichia coli, they do not possess any cytoskeleton in their cytoplasm.

E.

Summary Introduction

To explain: Nerve cell in the spinal cord contains a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: It contains a high density of intermediate filaments in their cytoplasm.

Explanation of Solution

The intermediate filaments as neurofilaments are present in the cytoplasm of nerve cell; they provide structural support and also help in regulating the axon diameter.

F.

Summary Introduction

To explain: Sperm cell contains a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: This cell does not contain high density of intermediate filaments in their cytoplasm.

Explanation of Solution

Sperm cell never develops or strengthens large tensile forces, so there is no need of cytoplasmic intermediate filaments.

G.

Summary Introduction

To explain: Plant cell contains a high density of intermediate filaments in their cytoplasm or not.

Introduction: Intermediate filaments are the components of cytoskeleton and found in the cytoplasm of almost all animals. These are also found in the nucleus of eukaryotic cell. It maintains the cell shape and rigidity. It also provides mechanical support to the cell but is not involved in the cell motility.

Answer to Problem 1Q

Correct answer: It does not have a high density of intermediate filaments in their cytoplasm.

Explanation of Solution

The rigid cell walls of the plant cell provide mechanical support to the plant rather than cytoplasmic intermediate filaments.