Science Answer the questions.[Bio-2M]

Cork cambium and vascular cambium help in secondary growth of stem and root.

Smooth muscles are found in alimentary canal and accomplish peristalsis movement.

White fibre: collagen protein.

Yellow fibre: elastin protein.

Plant tissue in husk of coconut is sclerenchvma fibres.

Reason for stiffness of scrererrchyma is deposition of iig'in in cell walls of its cells.

Parenchyma is the common living component of two complex permanent tissues, xylem and phloem.

Xylem parenchyma store food and helps in later conduction of water.

Phloem parenchyma store food, latex, resins, etc.

Eosinophils increases during worm infection.

1. Adipose tissues.
2. Ciliated epithelium.

1. Sensory neurons carry impulses towards brain.
2. Axon is long, branch process of neuron which carries impulses away from cyton.

1. Skeletal or striated muscle fibre is multinucleated.
2. Smooth or unstriated muscle fibre is long and spindle shape.

Xylem is composed of cells of four different types:

1. Tracheids.
2. Vessels or tracheae.
3. Xylem parenchyma.
4. Xylem Sclerenchyma.

Except xylem parenchyma, all other xylem elements are dead and bounded by thick lignified walls. Vessels are shorter and wider than tracheids. Vessels are very long tube-like structures formed by a row of cells placed end to end. Tracheids are elongated cells with tapering ends. They also conduct water.

1. Xylem helps in conduction of water and minerals.
2. Phloem helps in conduction of food.

Three types of muscles occur in animals namely striated muscles, smooth muscles and cardiac muscles.

Cartilage is present at the tip of nose and in the external ear.

1. Blood vessels.
2. Intestine.

Sieve tube elements do not have nuclei but have cytoplasm. They are dependent on adjacent companion cells which contains dense and very active cytoplasm and a large elongated nucleus.

The different types of elements present in the phloem are:

1. Sieve tubes: Sieve tubes are slender, tube-like structures composed of elongated thin-walled cells, placed end to end. Their end walls are perforated by numerous pores and are called sieve plates.

2. Companion cells: It is a small thin-walled cell containing dense and very active cytoplasm and large elongated nucleus.

3. Phloem parenchyma: These are thin-walled, living cells of parenchyma of phloem. They have two functions, storage and slow lateral conduction of food.

4. Phloem Fibre: These are thick-walled, elongated spindled shaped dead cells which posses narrow lumen. They provide mechanical strength to the tissue.

The various cells of connective tissue are fibroblasts, adipose cells, macrophages, mast cells and lymphocytes.

The protein fibres of connective tissue are white fibres of collagen, yellow fibres of elastin and reticular fibres of reticulin.

Four main types of animal tissues are:

1. Epithelial tissues.
2. Muscular tissues.
3. Connective tissues.
4. nervous tissue.

1. Parenchyma:

2. Collenchyma:

Xylem:

1. It conducts water and minerals.
2. Conducting channels or tracheary elements are tracheids and vessels.

Phloem:

1. It conducts organic solutes and food materials.
2. Conducting channels are sieve tubes.

Tracheids:

1. Single celled.
2. The end walls remain intact.

Vessels:

1. Made up of a row of cells.
2. End walls get dissolved and become perforated.

Squamous epithelium protects the underlying parts from germs, harmful chemicals and injury.

It is composed of a single layer of tall and slender cells. Their nuclei are located at the base. Free surface may have microvilli. It is generaly found in the lining of stomach and intestine and help in secretion and absorption.

Connective tissues are most abundant and widely distributed in the body of complex animals. The cells of connective tissue are loosely spaced and embedded in an inercellular matrix. The matrix may be jelly like, fluid, dense or rigid.

1. Muscular tissue.
2.  

1. Sarcoplasm.
2. Intercalated disc.
3. Nucleus.

3. It is cardiac muscles which are exclusively present in the wall of heart.