Tissues Class 9 Science Chapter 6 Important Questions, Download PDF

Multiple Choice Questions [1 Mark]

1. Vertical growth in plants takes place by
   (A) Lateral meristem
   (B) Apical meristem
   (C) Intercalary meristem
   (D) None of the above
   Answer: (B) Apical meristem

2. Assertion: Both apical meristem and intercalary meristems are primary meristems.
   Reason: They appear early in the life of the plant and contribute to the formation of the primary plant body.
   (A) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
   (B) Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
   (C) Assertion is true but Reason is false.
   (D) Assertion is false but Reason is true.
   Answer: (A)

3. Which of the following contains contractile proteins?
   (A) Cartilage
   (B) Muscles
   (C) Bones
   (D) Blood
   Answer: (B) Muscles

4. Which tissue has chloroplast in cells?
   (A) Xylem
   (B) Chlorenchyma
   (C) Sclerenchyma
   (D) Aerenchyma
   Answer: (B) Chlorenchyma

5. Intestine absorbs digested food materials. What type of epithelial tissue is responsible for that?
   (A) Stratified squamous epithelium
   (B) Columnar epithelium
   (C) Pseudostratified epithelium
   (D) Cuboidal epithelium
   Answer: (B) Columnar epithelium

6. The thickness of plant organs is due to____.
   (A) Intercalary meristem
   (B) Lateral meristem
   (C) Apical meristem
   (D) None of the above
   Answer: (B) Lateral meristem

7. What type of muscles are present in iris?
   (A) Voluntary muscles
   (B) Cardiac muscles
   (C) Skeletal muscles
   (D) Smooth muscles
   Answer: (D) Smooth muscles

8. Nissl’s granules are absent in
   (A) Cyton
   (B) Dendron
   (C) Axon
   (D) All of these
   Answer: (C) Axon

9. The tissue which makes plants hard and stiff is:
   (A) Parenchyma
   (B) Chlorenchyma
   (C) Collenchyma
   (D) Sclerenchyma
   Answer: (D) Sclerenchyma

10. The lining of oesophagus and mouth is covered with which type of epithelial tissue?
    (A) Cuboidal
    (B) Squamous
    (C) Columnar
    (D) Stratified columnar
    Answer: (B) Squamous

Very Short Answer Type Questions [1 Mark]

11. Where is apical meristem found?
    Answer: The apical meristem is found in the growing tips of stems and roots in plants.

12. Which tissue makes up the husk of coconut?
    Answer: Sclerenchyma tissue.

13. What are the constituents of phloem?
    Answer: The constituents of phloem are sieve tubes, companion cells, phloem parenchyma, and phloem fibers (bast).

14. Name the tissue responsible for movement in our body.
    Answer: Muscle/muscular tissue.

15. What does a neuron look like?
    Answer: A neuron comprises a cell body from which long thin hair-like parts arise. It has a single long part called axon and many short, branched parts called dendrites.

16. How are oxygen, food, hormones, and waste material transported in the body?
    Answer: They are transported through blood.

17. In desert plants, how does the rate of loss of water get reduced?
    Answer: Desert plants have a thick cuticle on leaf surfaces and stomata arranged in deep pits to reduce water loss. Some like Opuntia have leaves reduced to spines and perform photosynthesis through stems.

18. What are the types of epithelium tissue?
    Answer: The three main types are (i) simple epithelium, (ii) cuboidal epithelium, and (iii) columnar epithelium.

19. Which connective tissue is present around the heart, kidney, and eyeballs?
    Answer: Adipose tissue.

20. Why are corners of collenchyma thick?
    Answer: Due to deposition of cellulose, hemicellulose, and pectin, collenchyma cells have thickened corners.

Short Answer Type Questions [2 Marks]

21. Describe the structure and function of stomata.
    Answer: Stomata are small pores on leaf epidermis enclosed by two kidney-shaped guard cells. They help in gas exchange during photosynthesis and respiration and in transpiration.

22. Give one word for the following:
    (a) Group of cells with similar structure and function: Tissue
    (b) Process of taking a permanent shape, size, and function: Differentiation
    (c) Animal tissue connecting muscles to bones: Tendon
    (d) Kidney-shaped cells enclosing stomata: Guard cells

23. (a) Name elements of xylem tissue.
    (b) Which are responsible for transportation?
    (c) Which are dead?
    Answer: (a) Xylem parenchyma, xylem fibres, tracheids, and vessels.
    (b) Tracheids and vessels transport water.
    (c) Xylem fibres, tracheids, and vessels are dead.

24. Why are voluntary muscles also called skeletal muscles?
    Answer: Because they are mostly attached to bones and help in body movement.

25. Why does an organism require different types of cells?
    Answer: Different cell types specialize in different functions necessary for organism survival such as food transport and immunity.

26. What happens to cells formed by meristematic tissue?
    Answer: They differentiate into permanent tissue cells, losing their ability to divide.

27. Why is epidermis thick and waxy in desert plants?
    Answer: To prevent excessive water loss during transpiration.

28. Write a short note on xylem.
    Answer: Xylem is a complex permanent tissue consisting of tracheids, vessels, xylem parenchyma, and fibres. It transports water vertically and provides support.

29. Write a short note on phloem.
    Answer: Phloem is a complex permanent tissue made of sieve tubes, companion cells, fibres, and parenchyma. It transports food from leaves to other parts.

30. What are involuntary muscles? Where are they found?
    Answer: Muscles not under conscious control, called smooth muscles, found in alimentary canal, iris, ureters, and bronchi.

Short Answer Type Questions [3 Marks]

31. Why are plants and animals made of different types of tissue?
    Answer: Plants are autotrophic and stationary with mostly supportive dead tissues. Animals are heterotrophic and mobile with mostly living tissues needing energy. Growth patterns differ between them.

32. Differentiate between parenchyma and collenchyma.

33. Differentiate between collenchyma and sclerenchyma.

34. What is a neuron? Describe structure and functions.
    Answer:

Neurons are nerve cells with three parts: cell body (cyton) with Nissl’s granules, dendrites (branched fibers), and axon (long fiber ending in synaptic knobs). Neurons receive stimuli and conduct impulses to brain/spinal cord. 

• Cyton or cell body: The cell body contains cytoplasm with typical cell organelles and certain granular bodies called Nissl’s granules.

• Dendrites: Short fibers which branch repeatedly and project out of the cell body. They also contain Nissl’s granules and are called dendrites.

• Axon: The axon is a long fiber, the distal end of which is branched. Each branch terminates as a bulb-like structure called the synaptic knob, which possesses synaptic vesicles containing chemicals called neurotransmitters.

• Functions: Neurons have the ability to receive stimuli from within or outside the body and conduct impulses to different parts of the body. The impulses travel from one neuron to another neuron and finally to the brain or spinal cord.

35. Distinguish between simple and stratified epithelial tissue.

36. Write difference between cartilage and bone.

Long Answer Type Questions [5 Marks]

37. Reasons for the following:
    (a) Meristematic cells lack vacuole because they are actively dividing and need immediate food, not storage.
    (b) Sclerenchyma tissues lack intercellular spaces because cells are tightly packed for strength.
    (c) Pear fruit is crunchy due to lignin in sclerenchyma cell walls providing rigidity.
    (d) Tree branches bend in wind due to flexible collenchyma cells with thickened walls.
    (e) Coconut husk removal is hard due to tough lignified sclerenchyma cells.

(a) Meristematic cells are the continuously dividing cells in the plant body. They are metabolically active and require food instantly, so they do not store food. Hence, meristematic cells do not have vacuoles.
(b) Sclerenchyma tissue consists of dead, simple permanent cells that are tightly packed without intercellular spaces, like tiles in a mosaic floor. This arrangement gives the plant strength, rigidity, flexibility, and elasticity.
(c) Pear fruits are crunchy and granular because of sclerenchyma tissue. The presence of lignin thickens the sclerenchyma cell walls, making them strong and resistant to stretching or buckling.
(d) Collenchyma cells have thickened corners due to extra cellulose deposition. This tissue provides mechanical support and elasticity to branches, allowing them to bend and move in strong winds.
(e) Coconut husk contains abundant sclerenchyma cells with thick, lignified walls, making the husk tough and durable. This lignin content makes removing the husk challenging.

38. Describe striated and smooth muscles and their functions.

Answer: The striated muscle fibres are long or elongated, non-tapering, cylindrical, and unbranched. These muscle fibres show alternating dark and light stripes called striations, which is why they are called striated muscles. They are found in muscles of limbs, body wall, face, and neck.

Functions of striated muscles:

• Striated muscles are powerful and undergo rapid contraction and expansion.

• They provide the force for locomotion and all other voluntary movements of the body.

Smooth muscles, also known as unstriated or involuntary muscles, occur as bundles or sheets of elongated fusiform or spindle-shaped cells or fibres. They are held together by loose connective tissue. These muscle fibres are uninucleate and do not show visible bands or striations.

Smooth muscles are found in the walls of the alimentary canal, internal organs, ducts of glands, blood vessels, and in the stomach, intestine, ureters, bronchi, and iris of the eye.

Functions of smooth muscles:

• Smooth muscles work involuntarily and are responsible for movements such as food movement in the alimentary canal and contraction and relaxation of blood vessels.

• They contract slowly but can remain contracted for a long time, aiding in processes like moving food through the digestive tract.

39.  Draw and identify parts of phloem.
Answer: Sieve tubes, companion cells, phloem fibres and phloem parenchyma are the different elements of phloem.

40. What is a permanent tissue? Classify permanent tissues and describe them.

Solution:
Permanent tissues are derived from meristematic tissue whose cells have lost the power of division and have attained their definite forms. Permanent tissues are classified into two types:
(i) Simple permanent tissue
(ii) Complex permanent tissue

(i) Simple permanent tissues:
These tissues are composed of cells that are structurally and functionally similar. They are further divided into three types:

• Parenchyma: Forms the bulk of the plant body. Cells are living and possess the power of division.

• Collenchyma: Also living, characterized by extra cellulose deposition at cell corners, providing support and flexibility.

• Sclerenchyma: Dead cells devoid of protoplasm with thickened lignified walls, providing mechanical strength.

(ii) Complex permanent tissues:
Complex tissues consist of more than one type of cell derived from a common origin that work together for a common function. They include:

1. Xylem: A vascular and mechanical tissue composed of tracheids, vessels, xylem parenchyma, and xylem fibres. Tracheids and vessels transport water. Except for xylem parenchyma, all elements are dead with thick lignified walls.

2. Phloem: A vascular tissue without mechanical function, composed of sieve tubes, companion cells, phloem parenchyma, and phloem fibres. Sieve tubes and companion cells transport food, and all elements except phloem fibres are living.

41. Differentiate between striated, unstriated, and cardiac muscles based on structure and location.

42. Brief account of connective tissues and their functions:

(a) Areolar connective tissue:
A loose and cellular tissue that joins skin to muscles, fills spaces inside organs, and is found around muscles, blood vessels, and nerves.
Functions: Supports and packs organs, helps tissue repair, combats toxins, and fixes skin to muscles.

(b) Dense regular connective tissue:
Fibrous tissue with densely packed fibres and cells. Includes tendons (join muscle to bone) and ligaments (connect bones).
Functions: Tendons provide strong, inelastic attachment of muscles to bones; ligaments connect bones elastically.

(c) Adipose tissue:
Aggregates of fat cells found beneath skin, between organs, and in bone marrow.
Functions: Stores fat, shapes limbs, keeps organs in position, cushions organs like kidneys and eyeballs, and acts as an insulator to regulate heat loss.

43. Brief account of connective tissues:

(a) Skeletal tissue:
Includes bones and cartilage forming the endoskeleton.

• Cartilage: Compact, avascular, found in ear, nose, joints; provides support and flexibility and smoothens joints.

• Bone: Strong, inflexible; provides shape, skeletal support, protects vital organs, and anchors muscles.

(b) Fluid connective tissue:
Includes blood and lymph.

• Blood: Cells suspended in plasma; transports nutrients, hormones, vitamins, and wastes.

• Lymph: Colorless fluid filtered from blood capillaries; recirculates nutrients and removes CO2 and nitrogenous wastes from tissues.

Benefits of Important Questions Class 9 Science Chapter 6

Understand Key Ideas: Important questions help you grasp the main ideas about plant and animal tissues, making it easier to remember what you’ve learned.

Focus on What Matters: By studying important questions you can concentrate on topics that are most likely to appear in your exams, so you don’t waste time on less important material.

Think Critically: Many important questions ask you to compare and contrast different tissues, helping you develop your thinking skills.

Remember Better: Practicing these questions can help you remember information longer, making it easier to recall during your exams.

Spot Weak Areas: When you answer important questions, you can see where you might need more practice, allowing you to focus on those areas.

Improve Writing Skills: Answering questions helps you learn to express your ideas clearly, which is important for writing good answers in exams.

Boost Confidence: Knowing you’ve practiced important questions makes you feel more confident and less anxious when taking your exams.

Prepare for Future Studies: Understanding these basic concepts sets a strong foundation for more advanced studies in science later on.

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