Answer the following questions

Zoology

Tissue Level of Organisation

Evaluation

Answer the following questions

6. Some epithelia are pseudostratified. What does this mean?

These cells are columnar but unequal in size. Though the epithelium is single layered but it appears to be multi-layered because the nuclei lie at different levels in different cells.

7. Differentiate white adipose tissue from brown adipose tissue.

White adipose tissue

i. They have less number of Mitochondria.

ii. They store nutrients.

Brown adipose tissue

i. They have more numbers of mitochondria.

ii. It is used to heat the blood stream to warm the body.

8. Why blood is considered as a typical connective tissue?

Blood is the fluid connective tissue. Containing plasma red blood cells white blood cells and platelets.

It functions as the transport medium for the cardiovascular system carrying nutrients wastes respiratory gases through out the body.

9. Differentiate between elastic fibres and elastic connective tissue.

Elastic Fibres

i. It is found in the skin as the leathery dermis and forms fibrous capsules of organs such as kidneys bones and cartilages.

ii. It allows recoil of tissues following stretching.

iii. It maintains the pulsative flow of blood through the arteries and the passive recoil of lungs following inspiration.

Elastic connective tissue

i. This is present in tendons that attach skeletal muscles to bones and ligaments.

ii. It attaches one bone to another.

iii. It is able to with stand tension exerted in many directions and provides structural strength.

10. Name any four important functions of epithelial tissue and provide at least one example of a tissue that exemplifies each function.

Functions : Tissues

1. Protection : Squamous epithelium. In heart lungs and blood vessels as a protective covering.

2. Absorption : Columnar epithelium. (It lines tire digestive track)

3. Secretion : Cuboidal and columnar epithelium. Salivary gland endocrine glands.

4. Filteration:  Squamous epithelium glomerulus.

11. Write the classification of connective tissue and their functions

12. What is an epithelium? Enumerate the characteristic features of different epithelia.

Epithelial tissue is a sheet of cells that covers the body surface or lines the body cavity.

Types of epithelium

1. Squamous epithelium : Characters: Made up of single thin layer of flattened cells with irregular boundaries.

2. Cuboidal epithelium : Characters: Made up of single layer of cube like cells.

3. Columnar epithelium : Characters: Made up of single layer of tall cells with round to oval nuclei at the base.

4. Ciliated epithelium : Characters: It bears cilia on their free surfaces.

5. Nonciliated epithelium : Characters: There is no cilia on the free surfaces of columnar epithelium

6. Pseudo - stratified epithelium : Characters: Colomnar but unequal in size

7. Compound epithelium : Characters: Made up of more than one layer of cells.