Plant Tissues Class 9th Biology AP Board Solution

Class 9^th Biology AP Board Solution

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1. Tissue: Define the terms (AS 1)
2. Meristematic tissue: Define the terms (AS 1)
3. Dermal tissue: Define the terms (AS 1)
4. Meristematic tissue and Ground tissue Differentiate in between the following (AS 1)…
5. Apical meristem and lateral meristem Differentiate in between the following (AS 1)…
6. Parenchyma and collenchyma Differentiate in between the following (AS 1)…
7. Sclerenchyma and parenchyma Differentiate in between the following (AS 1)…
8. Xylem and phloem Differentiate in between the following (AS 1)
9. Epidermis and bark Differentiate in between the following (AS 1)
10. Growing tissue, which causes growth in the length of the plant. Name the following (AS 1)…
11. Growing tissue, which causes growth in the girth of the plant. Name the following (AS 1)…
12. Large air cavities in the aquatic plants. Name the following (AS 1)…
13. Food material in parenchyma. Name the following (AS 1)
14. Pores essential for gaseous exchange and transpiration. Name the following (AS 1)…
15. Xylem and phloem Compare and contrast the following (AS 1)
16. Meristematic tissue and Dermal tissue. Compare and contrast the following (AS 1)…
17. Xylem is a conductive tissue Give reasons to the following (AS 1)…
18. Epidermis gives protection Give reasons to the following (AS 1)
19. “Bark cells are impervious to gases and water”. What experiment will you perform to prove…
20. Chlorenchyma, Aerenchyma and storage tissue - Even though these three are parenchyma. Why…
21. Draw and label the diagram of the T.S. of the stem (AS 5)
22. MERISTEM: Describe the functions of - Meristem, Xylem, and phloem (AS 1)…
23. Xylem: Describe the functions of - Meristem, Xylem, and phloem (AS 1)…
24. Phloem: Describe the functions of - Meristem, Xylem, and phloem (AS 1)…
25. While observing internal parts of plants , how do you feel about its structure and…
26. If you want to know more about tissues in plants what questions you are going to ask? (AS…
27. Collect information about dermal tissues of plants in what way they help to them. (AS 4)…

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Question 1.

Define the terms (AS 1)

Tissue:

Answer:

Tissue is a group of cells similar in structure and performing similar functions. Four types of tissues in the plants are as follows:

i. Meristematic tissues: are tissues that bring about overall growth and repair.

ii. Dermal tissues: are that form outer coverings.

iii. Ground tissues: are tissues that form the bulk of the plant body, helping in packing other tissues

iv. Vascular tissues: are tissues that help in transport of materials.

Question 2.

Define the terms (AS 1)

Meristematic tissue:

Answer:

meristematic tissues are the tissues present on the tip, sides and in between layers of other tissues.

Meristematic tissues at the growing tip that bring about growth in length are called as apical meristematic tissues.

Tissues present around the edges in a lateral manner and giving rise to growth in girth of the stem are called lateral meristematic tissues.

Areas from which branching takes place or a leaf or a flower stalk grows this kind of meristematic tissue called as intercalary meristematic (also called as Cambium) tissue.

Question 3.

Define the terms (AS 1)

Dermal tissue:

Answer:

Tissues that form outer coverings are called as dermal tissues. Dermal tissue (Dermis) usually consists of a single layer of tissues having variations in the types of cell based on their functions and location.

Three different types of the epidermis (outer most layer), mesodermal (The middle layer) and endodermis (the innermost layer). In desert plants, it may be even more thick and waxy. Small pores in the epidermis of the leaf, called stomata.

Question 4.

Differentiate in between the following (AS 1)

Meristematic tissue and Ground tissue

Answer:

Question 5.

Differentiate in between the following (AS 1)

Apical meristem and lateral meristem

Answer:

Question 6.

Differentiate in between the following (AS 1)

Parenchyma and collenchyma

Answer:

Question 7.

Differentiate in between the following (AS 1)

Sclerenchyma and parenchyma

Answer:

Question 8.

Differentiate in between the following (AS 1)

Xylem and phloem

Answer:

Question 9.

Differentiate in between the following (AS 1)

Epidermis and bark

Answer:

Question 10.

Name the following (AS 1)

Growing tissue, which causes growth in the length of the plant.

Answer:

Apical meristematic tissues

Explanation: Meristematic tissues at the growing tip that bring about growth in length are called as apical meristematic tissues.

Question 11.

Name the following (AS 1)

Growing tissue, which causes growth in the girth of the plant.

Answer:

Lateral meristematic tissues

Explanation : Tissues present around the edges in a lateral manner and giving rise to growth in girth of the stem are called lateral meristematic tissues.

Question 12.

Name the following (AS 1)

Large air cavities in the aquatic plants.

Answer:

Aerenchyma.

Explanation: The Parenchyma which contains large air cavities or spaces is called Aerenchyma.

Question 13.

Name the following (AS 1)

Food material in parenchyma.

Answer:

Storage tissue.

Explanation: The Parenchyma which stores water or food or waste products is called Storage Tissue.

Question 14.

Name the following (AS 1)

Pores essential for gaseous exchange and transpiration.

Answer:

Stomata

Explanation: Stomata are dermal tissues that are essential for gaseous exchange and transpiration.

Question 15.

Compare and contrast the following (AS 1)

Xylem and phloem

Answer:

Question 16.

Compare and contrast the following (AS 1)

Meristematic tissue and Dermal tissue.

Answer:

Question 17.

Give reasons to the following (AS 1)

Xylem is a conductive tissue

Answer:

Xylem transports materials away from the root Xylem contains elongated tracheid cells, tubular vessels, fibers and parenchyma water to great heights in the plant body. It is up to nearly 200 ft of Eucalyptus plants and up to nearly 330 ft in the red wood trees. The xylem tracheary elements consist of cells known as tracheids and vessel members, both of which are typically narrow, hollow, and elongated. Water moves from tracheid to tracheid which serves to prevent the passage of damaging air bubbles. Vessel members are the principal water-conducting cells in angiosperms. Water flows relatively unimpeded from vessel to vessel through these perforations.

Question 18.

Give reasons to the following (AS 1)

Epidermis gives protection

Answer:

The dermal layer protects the plants from loss of water, mechanical damage and invasion by parasitic and disease-causing organisms. In big trees, the dermal tissue forms several layers above the epidermis known as bark. In desert plants, it may be even more thick and waxy.

Question 19.

“Bark cells are impervious to gases and water”. What experiment will you perform to prove this? (AS 3)

Answer:

As the stem ages and grows, changes occur that transform the surface of the stem into the bark. The epidermis is a layer of cells that cover the plant body, including the stems, leaves, flowers, and fruits, that protects the plant from the outside world. In old stems, the epidermis, cortex, and primary phloem become separated from the inner tissues by thicker formations of cork. Due to the thickening cork layer, these cells die because they do not receive water and nutrients. This dead layer is the rough corky bark that forms around tree trunks and other stems.

Cells of bark are dead and compactly arranged without intercellular spaces. They have a chemical called suberin in their walls that make them impervious to gases and water.

Bark tissues of made of woody vascular plants and consists of various biopolymers, tannins, lignin, suberin, and polysaccharides. Up to 40% of the bark tissue is made of lignin which forms an important part of a plant providing structural support by crosslinking between different polysaccharides, such as cellulose makes them impervious to gases and water.

Question 20.

Chlorenchyma, Aerenchyma and storage tissue – Even though these three are parenchyma. Why do they have special names? (AS 1)

Answer:

The cells of the parenchyma are soft, thin-walled and loosely packed. All parenchyma cells differ in their function.

The Parenchyma which contains chloroplasts is called “Chlorenchyma”. The Parenchyma which contains large air cavities or spaces

is called “Aerenchyma”. The Parenchyma which stores water or food or waste products is called “Storage Tissue”.

Question 21.

Draw and label the diagram of the T.S. of the stem (AS 5)

Answer:

Question 22.

Describe the functions of - Meristem, Xylem, and phloem (AS 1)

MERISTEM:

Answer:

MERISTEM: Meristematic tissues are the tissues present on the tip, sides and in between layers of other tissues. Depending on where the plant the meristem is, the meristem tissue can give rise to new leaves, flowers, or roots. The meristem is integral in plant growth—without it, plants would have no source for the production of new cells.

Apical meristem is found at the ends of roots (root apical meristem) or the tops of shoots (shoot apical meristem) of a plant responsible for the plant’s growth in length or height.

The shoot apical meristem found above ground, is composed of undifferentiated cells develop to become one of three primary meristems: the protoderm, ground meristem, or procambium. The protoderm will go on to form the epidermal tissues of the plant; the ground meristem will form the cortex and pith of the plant; and the procambium will become xylem and phloem, the vascular tissues of the plant.

The root apical meristem found below ground, is responsible for the growth and development of a plant’s roots. The root meristem produces cells in a bilateral direction, meaning that it yields two types of tissues at the same time.

Lateral meristem is responsible for lateral growth, or growth in diameter. This type of growth is known as secondary growth because it is growth around an already established stem.

Intercalary meristem or the basal meristem is located between mature, differentiated tissues. Although being relatively near an apical meristem and also composed of mostly undifferentiated cells, the intercalary meristem is distinctly different. It works independently of the apical meristem to promote the vertical growth of the plant. This allows leaves to continue growing despite being cut, in the way blades of grass continue to grow after being mowed.

Question 23.

Describe the functions of - Meristem, Xylem, and phloem (AS 1)

Xylem:

Answer:

Xylem consists of tracheids, vessels, xylem fibers, xylem parenchyma. Which transports water and minerals from roots to apical parts of the plant. Functions are to transport materials away from the root Xylem containing elongated tracheid cells, tubular vessels, fibers and parenchyma water to great heights in the plant body. It is up to nearly 200 ft of Eucalyptus plants and up to nearly 330 ft in the red wood trees. The xylem tracheary elements consist of cells known as tracheids and vessel members, both of which are typically narrow, hollow, and elongated. Water moves from tracheid to tracheid which serves to prevent the passage of damaging air bubbles. Vessel members are the principal water-conducting cells in angiosperms. Water flows relatively unimpeded from vessel to vessel through these perforations.

Question 24.

Describe the functions of - Meristem, Xylem, and phloem (AS 1)

Phloem:

Answer:

It transports food material from leaves to growing parts of plants. Pholem consists of sieve tubes, sieve cells, companion cells , phloem fibres, phloem parenchyma. Sieve tubes, sieve cells, companion cells and phloem parenchyma are living. The sap is a water-based solution, but rich in sugars made by photosynthesis. These sugars are transported to non-photosynthetic parts of the plant, such as the roots, or into storage structures. During the plant's growth period, usually during the spring, storage organs such as the roots are sugar sources, and the plant's many growing areas are sugar sinks. The movement in phloem is multidirectional. After the growth period the leaves are sources, and storage organs are sinks. Developing seed-bearing organs (such as fruit) are always sinks. Because of this multi-directional flow, coupled with the fact that sap cannot move with ease between adjacent sieve-tubes, it is not unusual for sap in adjacent sieve-tubes to be flowing in opposite directions.

Question 25.

While observing internal parts of plants , how do you feel about its structure and functions? (AS 6)

Answer:

Plants that we observe around us are usually multi-cellular. They perform several life processes such as growth, respiration, excretion, photosynthesis. Plants internal structure is responsible for these processes.

Question 26.

If you want to know more about tissues in plants what questions you are going to ask? (AS 2)

Answer:

Few questions that arise to know more about plants tissues are as follows , Are all the cells similar, How are the cells arranged ,Are all the cells similar , Is there any difference in their arrangement, What can we infer from the above activities, How will the leaves come Which portion of the plant is responsible for this transport.

Question 27.

Collect information about dermal tissues of plants in what way they help to them. (AS 4)

Answer:

Dermal tissues of plants help them in following ways –

a) In desert plants cell walls of dermal tissues are even more thick and waxy.

b) Epidermis the dermal tissue layer has Small pores called stomata. They are enclosed by two kidney shaped cells, called guard cells.

c) Cells of the roots have long-hair like parts, called root hairs.

d) The dermal layer protects the plants from loss of water, mechanical damage and invasion by parasitic and disease-causing organisms.

e) In big trees the dermal tissue forms several layers above the epidermis. It is called bark.

f) Stomata and root hair are also dermal tissues that are essential for gaseous exchange and transpiration as well as absorption of water and minerals respectively. Photosynthesis is also carriedout by certain cells of dermal tissue.