Science Do as directed; [Bio-1 M]

1. The common name of xylem is wood.
2. The common name of phloem is bast.

1. It helps in supporting internal organs.
2. It helps in repairing the tissues of the skin and muscles.

1. These granules are rough endoplasmic reticulum (with ribosomes) and are the site of protein synthesis.
2. Nissl bodies show changes under various physiological conditions and in pathological conditions they may dissolve and disappear (karyolysis).

4. Living cells, thin-walled, large intercellular spaces.

Explanation:

Parenchyma cells are living and thin walled. They are oval, spherical or polygonal in shape. They have large, intercellular space between the cells.

4. Dendrites, cell body, axon, nerve endings.

Explanation:

Nerve impulse travel along the axons and dentrites. Nerve impulses enter a neuron along the dentrites and leave the neuron along the axon. Thus, the correct sequence through which nerve impulse is transmitted is: dendrites, cell body, axon, nerve endings.

• Parenchyma.
• Collenchymas.
• Selerenchyma.

1. Multinucleate muscle fibre: Striated muscle fibres which are present in limbs, tongue, hands.

2. Spindle shaped Fibre: Unstriated muscle fibres which are present in iris of the eye, bronchi.

Explanation:

2. Only skeletal muscle cells.

Explanation:

The striated muscle cells are long, cylindrical, unbranched and multinucleate.

1. It provides mechanical support and elasticity.
2. It provides tensile strength to the plants.