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Q1. Where do you find adipose tissue?

Solution

Adipose tissue is found below the skin and between the internal organs.

Q2. Write a short note on stomata.

Solution

Stomata are microscopic pores found mostly on the underside of leaves. They are located in the epidermal tissue. Each stoma is surrounded by a pair of specialised, kidney-shaped cells called guard cells, which possess chlorophyll and regulate the opening and closing of stomata. The primary function of stomata is to allow gaseous exchange duaring photosynthesis and respiration between the plant's internal tissues and the atmosphere. The process of transpiration also takes place through the stomata.

Q3. Differentiate between cuboidal epithelium and columnar epithelium.

Solution

Differences between cuboidal epithelium and columnar epithelium:       Cuboidal epithelium Columnar epithelium   1. Cells are cube-shaped. Cells are tall and column-like.   2. Provides mechanical support. Helps in absorption and secretion. Facilitates movement across the epithelial barrier.   3.   Forms the lining of kidney tubules and ducts of salivary glands. Forms the inner lining of the intestine, stomach, colon and gall bladder.

Q4. What do you understand by complex tissues? Name the two types of complex permanent tissues present in plants? Give one function of each complex tissue.

Solution

Complex tissue is a tissue made up of more than one type of cells. The two types of complex tissues are: Xylem Phloem Xylem conducts water and minerals from the soil to different parts of the plant. Phloem conducts prepared food from the leaves to all the parts of the plant.

Q5. Name the tissue present in the hard covering of seeds. Which chemical is responsible for making the tissue hard?

Solution

The tissue present in the hard covering of seeds is sclerenchyma tissue. Lignin is the chemical which is responsible for making the tissue hard.

Q6. How does squamous epithelium differ in function from cuboidal epithelium?

Solution

Squamous epithelium protects the underlying parts of the body and also forms a selectively permeable surface for the transport of materials. On the other hand, cuboidal epithelium provides mechanical support to the body parts where it is present.

Q7. Name the type of tissue whose cells are filled with fat globules. State its function.

Solution

Adipose tissue is filled with fat globules. It acts as an insulator.

Q8. Answer the following in one word or one sentence: i. Name the plant tissue associated with the transport of food. ii. Name the plant tissue associated with the conduction of water and minerals. iii. Identify the type of tissue in: (a) Bark of a tree (b) Vascular bundles

Solution

 i. Phloem  ii. Xylem  iii. (a) Protective tissue (Simple permanent tissue)      (b) Conducting tissue (Complex permanent tissue)

Q9. Discuss three structural features of bone tissue.

Solution

Structural features of bone tissue: i. In the bone tissue, the matrix is in the form of thin concentric rings called lamellae. ii. Bone cells, called osteocytes, are present between the lamellae in fluid filled spaces called lacunae. iii. All lacunae communicate with each other by a network of fine canals called canaliculi.

Q10. How does blood and areolar tissue differ in terms of the cells present in them?

Solution

Blood shows three types of cells which are red blood cells, white blood cells and platelets. Areolar tissue shows cells like fibroblasts, macrophages, plasma cells, and mast cells.

Q11. Fill in the blanks and complete the table: Type of tissue Shape of the cells Intercellular spaces Protoplasm Parenchyma   _________________ Abundant ________________ ________________   Elongated in shape Absent ________________ ________________ _________________ Absent Devoid of protoplasm  

Solution

Type of tissue Shape of the cells Intercellular spaces Protoplasm Parenchyma Isodiametric Abundant Living protoplasm Collenchyma Elongated in shape Absent Living protoplasm Sclerenchyma Fibres- Long and slender Sclereids- Variable in shape Absent Devoid of protoplasm

Q12. What will happen if a potted plant is covered with a glass jar? Why?

Solution

If a potted plant is covered with a glass jar, water vapour appears on the wall of the glass jar because water is released from the plant in the form of water vapour due to transpiration. This water vapour condenses on the walls of the glass jar and appears as fine water droplets.

Q13. Name the tissue responsible for flexibility in plants. How would you differentiate it from other permanent tissues?

Solution

Collenchyma is responsible for flexibility in plants. Difference between collenchyma and other permanent tissues: Parenchyma Collenchyma Sclerenchyma It consists of relatively unspecialised cells with thin walls. The cells of this tissue are living. The cells of this tissue are living, elongated and irregularly thickened at the corners. The cells of this tissue are dead. They are long and narrow as the walls are thickened due to lignin. The cells in this tissue contain large intercellular spaces. The cells in this tissue have very little intercellular space. The walls of cells are so thick that there is no internal space inside the cell and between the cells. It provides support to plants and also stores food. It allows easy bending in various parts of a plant (leaf, stem) without breaking. It also provides mechanical support to plants. It provides strength to the plant parts.

Q14. Name the different types of meristematic tissues present in plants.

Solution

Types of meristematic tissues in plants: i. Apical meristem ii. Lateral meristem iii. Intercalary meristem

Q15. Name the tissue found in the following locations: (a) Haversian canal (b) Chondrocyte (c) Eosinophils Give one function of each of these.

Solution

Bone tissue is present in the Haversian canal. Nerve and blood vessels pass through this canal. Cartilage is the type of tissue found in chondrocyte. It produces and maintains a cartilaginous matrix. Eosinophils are present in the blood tissue. They help in the defence mechanism of the body.

Q16. Differentiate between cardiac muscles and striated muscles.

Solution

 Differences between cardiac muscles and striated muscles:   Cardiac muscles Striated muscles i. They have uninucleated cells. They have multinucleated cells. ii. They are involuntary. They are voluntary. iii. They do not need rest. They get tired and often need rest.

Q17. State in brief three roles of the epidermis in plants.

Solution

Role of the epidermis in plants: (i)Protection (ii)Exchange of gases (iii)Absorption (iv)Water resistance (v)Formation of cork

Q18. Write the functions of any two components of phloem.

Solution

Sieve tubes, companion cells, phloem fibres and phloem parenchyma are the components of phloem. Function of sieve tubes: Translocation of organic substances through perforated walls from one adjacent cell to another. Function of companion cells: Help to control the activity of sieve tube elements. Function of phloem parenchyma: Transports food, i.e. sugars and amino acids from leaves to other non-green parts of plants such as growing stems and roots. Function of phloem fibres: Provide mechanical strength to the plant.

Q19. Name the different types of elements found in the phloem.

Solution

Phloem is composed of four types of elements: i. Sieve tubes ii. Companion cells iii. Phloem parenchyma iv. Phloem fibres

Q20. What is lignin? What are its functions?

Solution

Lignin is a complex polymer which acts as a cementing material and hardens the cell wall. It provides flexibility and great tensile and compressional strength.

Q21. How does the position of the nucleus differ in striated muscle cell and smooth muscle cell?

Solution

The nucleus is centrally located in the smooth muscle cell, whereas in the striated muscle cell, the nucleus is peripheral and just below the surface membrane.

Q22. In a temporary mount of a leaf epidermis we observe small pores. (a) What are the pores present in the leaf epidermis called? (b) How are these pores beneficial to the plant?

Solution

(a) The pores present in the leaf epidermis are called stomata. (b) Stomata help in the exchange of gases and process of transpiration.

Q23. List any four salient features of meristematic tissue.

Solution

Features of meristematic tissue: (i) Cells divide repeatedly. (ii) Cell walls are thin. (iii) Vacuoles are not found. (iv) Metabolically very active. (v) They have a dense cytoplasm. (vi) They have a prominent nucleus.

Q24. Discuss three structural features of striated muscles.

Solution

Structural features of striated muscles: (a)Striated muscles show alternate light and dark bands when stained. (b)The striated muscle cells are long, cylindrical and unbranched. (c)Their cells are multinucleate.

Q25. Give one function of each: (a) Stratified squamous epithelium (b) Columnar epithelium

Solution

a) Stratified squamous epithelium: Prevents the wear and tear of the skin and helps it to protect the underlying organs.  b) Columnar epithelium: Helps in absorption and secretion.

Q26. Write any two functions of cork.

Solution

Functions of cork: (i) Prevents desiccation, infection and mechanical injury. (ii) Used as a shock absorber, in flooring, and making of sports goods.

Q27. Branches of a tree move and bend freely in high wind velocity. Give reason.

Solution

Branches of a tree move and bend freely in high wind velocity because of the presence of collenchyma tissue which imparts the property of flexibility.

Q28. How do the cells of cuboidal epithelium differ from that of ciliated epithelium?

Solution

The cells of cuboidal epithelium are cube-shaped. On the other hand, the cells of ciliated epithelium are tall and pillar-like, with hair-like cilia on their outer surfaces.

Q29. Give four locations in the body where smooth muscles are found.

Solution

Smooth muscles are present in the alimentary canal, iris of the eye, in ureters and in the bronchi of lungs.

Q30. Discuss the structure of a neuron.

Solution

A neuron consists of three parts – cyton, dendrites and axon. Cyton is also called cell body. It is the broad part of the neuron and contains a central nucleus and cytoplasm. From the cyton arise several thin, short, branched processes called dendrites. The axon is a single, long, cylindrical process arising from the cyton.