CBSE Class 9 Science Chapter 03 Tissues In Action MCQs Set 01

Answer: (B) It allows groups of cells to specialise and work efficiently for complex functions

Explanation:
When cells with similar structure group together and specialise, the body carries out complex processes more efficiently instead of a single cell doing everything, as happens in unicellular organisms like amoeba.

Answer: (B) The actively dividing cells at the root tip were removed

Explanation:
Root growth depends on continuously dividing cells located right at the tip, the apical meristem. Once this region is cut away, no new cells are added, so elongation stops even though Jar A keeps growing normally.

Answer: (C) Intercalary meristem

Explanation:
Regrowth after cutting happens because of meristematic tissue located at the base of internodes or just above nodes, which is exactly what the intercalary meristem does in hedges and grasses.

Answer: (C) Thin walls, dense cytoplasm, prominent nucleus and absence of vacuoles

Explanation:
Meristematic cells are small and tightly packed, with thin walls, a large nucleus and dense cytoplasm full of organelles, and they generally lack vacuoles — all features suited for constant, rapid cell division.

Answer: (B) The age of the tree and the climatic conditions during its growth

Explanation:
Wide rings form in favourable years and narrow ones in unfavourable years, so the pattern of rings reveals both how old a tree is and what conditions it experienced while growing.

Answer: (B) It undergoes differentiation and loses its ability to divide

Explanation:
Some cells produced by meristems stop dividing and change in structure and function to take up specialised roles like support or storage — this specialisation process is called differentiation.

Answer: (B) To minimise water loss through transpiration

Explanation:
A thicker waxy cuticle layer cuts down evaporation of water vapour through the stomata, which is especially important for plants that live in dry habitats where conserving water matters most.

Answer: (B) Collenchyma - unevenly thickened corners with pectin for flexible support

Explanation:
Collenchyma cells have corners thickened with pectin, a substance that behaves somewhat like flexible rubber, letting stems and tendrils bend without snapping. The other pairings mix up features that actually belong to different tissues.

Answer: (B) Fresh twigs have living, flexible collenchyma providing pliability, unlike the brittle dead tissue in dry twigs

Explanation:
Living supporting tissues such as collenchyma give young stems flexibility, whereas dried-out tissue loses this pliability and becomes brittle, causing it to snap under stress instead of bending.

Answer: (C) are composed of several different types of cells working together

Explanation:
Unlike simple tissues, both xylem and phloem contain multiple distinct cell types — for instance xylem has tracheids, vessels, parenchyma and fibres — that cooperate to move substances through the plant.

Answer: (B) They regulate the loading and unloading of sugars into sieve tubes

Explanation:
Companion cells are specialised parenchyma cells that sit alongside sieve tubes and control the movement of sugars in and out of them, since the sieve tube cells themselves cannot manage this on their own.

Answer: (C) Efficient absorption of nutrients and water

Explanation:
Tall, columnar cells arranged in a single layer, often bearing hair-like structures, increase surface area and are typical of tissue built for absorbing nutrients, as found lining the small intestine.

Answer: (B) The nature of the matrix surrounding their cells

Explanation:
Both tissues connect and support body parts, but their matrix differs greatly — watery and jelly-like in blood versus hard and mineral-rich in bone — which explains their very different consistencies.

Answer: (C) Cardiac muscle - branched fibres with a single nucleus and faint striations

Explanation:
• Skeletal muscle: unbranched, multinucleate, clearly striated
• Smooth muscle: spindle-shaped, single nucleus, no striations
• Cardiac muscle: branched fibres, single nucleus, faint striations — this matches only option (c) correctly

Answer: (C) Nervous tissue

Explanation:
Coordinating body activities and sending instructions to organs like the heart is the job of nervous tissue, built from neurons that receive, process and transmit messages throughout the body.

Answer: (B) Apical meristem

Explanation:
Located right at the tips of roots and shoots, this tissue contains constantly dividing cells that push growth upward and downward, adding to height and depth respectively.

Answer: (B) A ring of dividing cells inside the stem that adds new cells inward and outward

Explanation:
• Girth increase is not about length, it is about diameter.
• A circular band of actively dividing cells runs around the stem.
• These cells add new tissue on both sides in a concentric pattern, called the lateral meristem, which is what forms the annual rings seen in tree trunks.

Answer: (C) Vascular tissue system

Explanation:
Since xylem carries water and minerals while phloem carries food, and both act as the plant's internal transport network, they are grouped as the vascular tissue system, distinct from the outer dermal covering and the inner ground tissue.

Answer: (D) Xylem parenchyma

Explanation:
Tracheids, vessels and xylem fibres are essentially sclerenchymatous and dead once mature, giving xylem its rigidity, but xylem parenchyma retains living cytoplasm and remains functional.

Answer: (C) Sclerenchyma, with thick lignin-coated walls in mostly dead cells

Explanation:
Lignin deposition makes sclerenchyma cell walls stiff and strong, and since most of these cells die once mature, the tissue behaves like a rigid, woody covering rather than a soft, flexible one.

Answer: (D) Pivot joint

Explanation:
This joint works somewhat like a doorknob turning within its fitting, letting the head swing from side to side rather than bend up-down or rotate fully like the shoulder does.

Answer: (B) To keep the brain and delicate sense organs shielded by preventing any shifting between the bones

Explanation:
Movement between skull bones would risk injury to the brain, eyes and ears housed inside, so these bones are locked together permanently for protection rather than mobility.

Answer: (B) A mature, differentiated plant cell can dedifferentiate and regenerate an entire organism, a property called totipotency

Explanation:
• Steward began with fully mature phloem cells, not embryonic ones.
• These cells first lost their specialised identity (dedifferentiated) and formed an unspecialised cell mass.
• Given the right nutrients and hormones, that mass redifferentiated into roots, shoots and a complete plant, showing totipotency, much as a zygote develops into a full organism.

Answer: (B) Using it as a vehicle to insert desirable genes into plants for crop improvement

Explanation:
Rather than stopping at curing the tumour-like swellings the bacterium causes, scientists studied how it naturally transfers its own genetic material into plant cells, and turned this ability into a tool of genetic engineering for producing disease-resistant and improved crop varieties.

Answer: (B) An anther grown on an artificial nutrient medium

Explanation:
Their anther culture technique, carried out under controlled laboratory conditions, was a landmark contribution that later helped advance crop improvement in Indian agriculture.