Sieve tubes, companion cells, phloem fibres and phloem parenchyma.

(a) Epithelial tissue is protective tissue in animal body.
(b) The lining of blood vessels, lung alveoli and kidney tubules are all made up of epithelial tissue.
(c) Epithelial cells have a lot of intercellular spaces.
(d) Epithelial layer is permeable layer.
(e) Epithelial layer does not allow regulation of materials between body and external environment.
Ans. (a)—T, (b)—T, (c)—F, (d) —T, (e)—F

Differentiate the following activities on the basis of voluntary (V) or involuntary (IV) muscles.
(a) Jumping of frog
(b) Pumping of the heart
(c) Writing with hand
(d) Movement of chocolate in your intestine
Ans. (a)—V, (b)—IV, (c)—V, (d) —IV

(a) Lining of blood vessels is made up of __________.
Ans. squamous epithelium
(b) Lining of small intestine is made up of __________.
Ans. columnar epithelium
(c) Lining of kidney tubules is made up of __________.
Ans. cuboidal epithelium
(d) Epithelial cells with cilia are found in __________ of our body.
Ans. respiratory tract

A special type of parenchyma; called aernchyma is present in water hyacinth. This tissue has air-filled spaces inside. Due to this, water hyacinth floats on water surface.

Epidermis having thick cuticle and waxy substances to prevent the invasion of parasites.

(a) Cork cells possesses __________ on their walls that makes it impervious to gases and water.
Ans. suberin
(b) __________ have tubular cells with perforated walls and are living in nature.
Ans. sieve tubes
(c) Bone possesses a hard matrix composed of __________ and __________.
Ans. calcium and phosphorus