NCERT 9th Class (CBSE) Science: Tissues

Question: Give the functions of cartilage.

Answer:

1. It provides support and flexibility to the body parts.
2. It smoothens surface at joints.

Question: Fill in the blanks:

1. Water and minerals are conducted by ………………….
2. In higher plants food is conducted by …………………..
3. Blood is a ……………. tissue.
4. Bone consists of………….cells.
5. Cartilage consists of………………..cells.
6. Fibres are absent in………….type of connective tissue.

Answer:

1. Xylem
2. Phloem
3. Connective
4. Osteocyte
5. Chondrocyte
6. Blood

Question: What are the functions of areolar tissue?

Answer: Functions are:

1. It helps in repair of tissues after an injury.
2. It also helps in combating foreign toxins.
3. It fixes skin to underlying muscles.

Question: Give difference between xylem and phloem.

Answer: Xylem:

1. It consists of mainly dead elements.
2. It conducts water and minerals.
3. It provides mechanical strength to the plant.

Phloem:

1. It consists of mainly dead elements.
2. It conducts food
3. It does not provides mechanical strength to the plant.

Question: What are fibres?

Answer: Fibers consist of very long, narrow and thick cells. Example, jute fiber.

Question: Name the tissues for the following:

1. Stores fat in animal body.
2. Divides and re-divides to grow in plants.
3. Tissue that joins hone to hone.
4. Covers the external surface of animal body.

Answer:

1. Adipose tissue
2. Meristematic tissue
3. Ligament
4. Epithelial tissue

Question: What is stomata?

Answer: Stomata are small pores present on the surface of a leaf which helps in the exchange of gases and in transpiration.

Question: Why does epidermal tissue have no intercellular space?

Answer: The epidermal (layer) tissue forms a protective outer covering for the plants and it protects the internal parts of the plant. It aid in the protection against loss of water, mechanical injury and invasion by parasitic fungi.
For this protective role to play the continuation of cells is necessary, hence it does not have inter-cellular space.

Question: Name and give the function of each cell of xylem.

Answer: Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.
Tracheids and vessels—Allows the transport of water and minerals.
Xylem parenchyma—Stores food and helps in the sideways conduction of water.
Xylem fibres—Are supportive in function.

Question: What is the function and location of stratified squamous epithelium?

Answer: Stratified squamous epithelium is present in the skin. The layers of cells are arranged to prevent wear and tear.

Question: Give difference between ligament and tendon.

Answer: Ligament:

1. Ligament helps in connecting bone to bone.
2. It is elastic and flexible.

Tendon:

1. Ligament helps in connecting bone to muscles.
2. It is strong and not-flexible.

Question: Give difference between striated muscles and unstriated muscles.

Answer: Striated Muscles:

1. They are skeletal muscles.
2. They show alternate light and dark bands.
3. Voluntary muscles.
4. Cells are cylindrical, multi-nucleated.

Unstriated Muscles:

1. They are skeletal muscles.
2. These muscles do not show such bands.
3. Involuntary muscle.
4. Cells are tapering, multi-nucleated.