The specific function of the cardiac muscle is to control the contraction and relaxation of the heart.

Epidermis is important for plants due to the following reasons
(i) it gives protection
(ii) helps in gaseous exchange
(iii) checks water loss
(iv) root hairs arising from epidermis helps in absorption of water and minerals.

Give reasons for
(a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole.
Ans. Cells of meristematic tissue are capable of division. Hence, prominent nucleus and dense cytoplasm are present in these cells. Since these cells continuously undergo division hence they do not need to maintain a particular shape and store food. Due to this, vacuoles are not required in these cells.

(b) Intercellular spaces are absent in sclerenchymatous tissues.
Ans. Cell wall in sclerenchyma is lignified. Due to this, intercellular spaces are absent in sclerenchymatous tissues.

(c) We get a crunchy and granular feeling, when we chew pear fruit.
Ans. In a pear fruit, cells of scelerenhyma are small and called stone cells. We get the crunchy feeling due to these stone cells.

(d) Branches of a tree move and bend freely in high wind velocity.
Ans. Collenchyma is present at junction of a branch. Collenchyma provides rigidity with flexibility. Due to this, branches of tree move and bend freely in high wind velocity.

(e) It is difficult to pull out the husk of a coconut tree.
Ans. The husk of coconut tree is composed of sclerenhyma. Due this, the husk is very hard and is difficult to be pulled out.

16. Voluntary muscles are found in
(a) alimentary canal
(b) limbs
(c) iris of the eye
(d) bronchi of lungs
Ans. (b) limbs
Explanation: movement of organs in other options is not under our conscious control. Hence, voluntary muscles are not found in them.

17. Nervous tissue is not found in
(a) brain
(b) spinal cord
(c) tendons
(d) nerves
Ans. (c) tendons

18. Nerve cell does not contain
(a) axon
(b) nerve endings
(c) tendons
(d) dendrites
Ans. (c) tendons 
Explanation: Tendon is a type of connective tissue, while nerve cells compose the nervous tissue.

19. Which of the following helps in repair of tissue and fills up the space inside the organ?
(a) Tendon
(b) Adipose tissue
(c) Areolar
(d) Cartilage
Ans. (c) Areolar
Explanation: Areolar tissue fills the space inside the organ, supports internal organs and helps in repair of tissue. 

20. The muscular tissue which function throughout the life continuously without fatigue is
(a) skeletal muscle
(b) cardiac muscle
(c) smooth muscle
(d) voluntary muscle
Ans. (b) cardiac muscle
Explanation: This is the reason; our heart keeps on pumping the blood throughout the life. Other types of muscles work as and when required because they do not need to work continuously.

21. Which of the following cells is found in the cartilaginous tissue of the body?
(a) Mast cells
(b) Basophils
(c) Osteocytes
(d) Chondrocytes
Ans. (d) Chondrocytes
Explanation: Mast cells are found in areolar tissue, basophils are found in blood and osteocytes are found in bone.

22. The dead element present in the phloem is
(a) companion cells
(b) phloem fibres
(c) phloem parenchyma
(d) sieve tubes
Ans. (b) phloem fibres

23. Which of the following does not lose their nucleus at maturity?
(a) Companion cells
(b) Red blood cells
(c) Vessel
(d) Sieve tube cells
Ans. (a) Companion cells

24. In desert plants, rate of water loss gets reduced due to the presence of
(a) cuticle
(b) stomata
(c) lignin
(d) suberin
Ans. (a) cuticle
Explanation: Cuticle works as protective layer to minimize the effect of heat. Thus, cuticle helps in reducing water loss in desert plants.

25. A long tree has several branches. The tissue that helps in the sideways conduction of water in the branches is 
(a) collenchyma
(b) xylem parenchyma
(c) parenchyma
(d) xylem vessels
Ans. (d) xylem vessels
Explanation: Collenchyma has no role in transport of water. Parenchyma is a supportive tissue and has nothing to do with conduction of water.

26. If the tip of sugarcane plant is removed from the field, even then it keeps on growing in length. It is due to the presence of 
(a) cambium
(b) apical meristem
(c) lateral meristem
(d) intercalary meristem
Ans. (d) intercalary meristem
Explanation: Intercalary meristem facilities the longitudinal growth of internode and thus a sugarcane plant keeps on growing even in the absence of apical meristem.

27. A nail is inserted in the trunk of a tree at a height of 1 metre from the ground level. After 3 years the nail will
(a) move downwards
(b) move upwards
(c) remain at the same position
(d) move sideways
Ans. (c) remain at the same position
Explanation: Longitudinal growth in stem takes place at the top. So, portion below the apical meristem will remain at a constant level even after growth.

28. Parenchyma cells are
(a) relatively unspecified and thin walled
(b) thick walled and specialised
(c) lignified
(d) none of these
Ans. (a) relatively unspecified and thin walled
Explanation: Parenchyma is simplest among simple tissues. Hence, cells are thin-walled and relatively unspecified.

29. Flexibility in plants is due to
(a) collenchyma
(b) sclerenchyma
(c) parenchyma
(d) chlorenchyma
Ans. (a) collenchyma
Explanation: Collenchyma provides rigidity with some flexibility. This is possible because of thickening of cells at corners

30. Cork cells are made impervious to water and gases by the presence of
(a) cellulose
(b) lipids
(c) suberin
(d) lignin
Ans. (c) suberin

31. Survival of plants in terrestrial environment has been made possible by the presence of
(a) intercalary meristem
(b) conducting tissue
(c) apical meristem
(d) parenchymatous tissue
Ans. (b) conducting tissue
Explanation: It is because of conducing tissues that plants are able to take up water from soil. Thus, plants could be able to survive in terrestrial environment where availability of water can be a major issue.

32. Choose the wrong statement
(a) The nature of matrix differs according to the function of the tissue
(b) Fats are stored below the skin and in between the internal organs
(c) Epithelial tissues have intercellular spaces between them
(d) Cells of striated muscles are multinucleate and unbranched
Ans. (c) Epithelial tissues have intercellular spaces between them
Explanation: Epithelial tissues do not have intercellular spaces between them, rather cells are tightly fit together to make a continuous sheet.

33. The water conducting tissue generally present in gymnosperm is
(a) vessels
(b) sieve tube
(c) tracheids
(d) xylem fibres
Ans. (c) tracheids
Explanation: Sieve tubes are present in phloem and hence have no role in transport of water. Xylem fibres provides structural rigidity and have no role in conduction of water. Vessels are generally absent in gymnosperms.