ICSE Class 9 Biology Syllabus

Name the three types of simple permanent tissue in plants.

Parenchyma, collenchyma, and sclerenchyma.

What is parenchyma and its function?

Simple living tissue of thin-walled, loosely packed cells; functions in storage, photosynthesis (chlorenchyma), and buoyancy (aerenchyma).

What is collenchyma and its function?

Living tissue with cells thickened at the corners by cellulose and pectin; provides mechanical support and flexibility to growing parts like young stems and leaf stalks.

What is sclerenchyma and its function?

Dead tissue with thick, lignified walls; provides mechanical strength and rigidity. Includes fibres and sclereids (stone cells).

Name the two complex (conducting) permanent tissues in plants and what each transports.

Xylem - conducts water and minerals upward from roots; phloem - conducts food (sugars) from leaves to other parts.

Name the four components of xylem.

Tracheids, vessels (tracheae), xylem parenchyma, and xylem fibres.

Name the four components of phloem.

Sieve tubes, companion cells, phloem parenchyma, and phloem fibres.

Which is the only living component of xylem, and which is the only dead component of phloem?

Living component of xylem: xylem parenchyma. Dead component of phloem: phloem fibres.

What is a flower?

The reproductive part of a flowering plant (angiosperm), specially modified to carry out sexual reproduction and produce seeds and fruits.

Name the four whorls of a typical flower from outside to inside.

Calyx (sepals), corolla (petals), androecium (stamens), and gynoecium/pistil (carpels).

What is the calyx, and what is its function?

The outermost whorl made of sepals (usually green); it protects the flower in the bud stage.

What is the corolla, and what is its function?

The whorl of petals, often brightly coloured; it attracts insects/pollinators and protects the inner whorls.

What are the parts of a stamen (the male reproductive unit)?

A stamen consists of a filament (stalk) and an anther, which produces pollen grains containing male gametes.

What are the three parts of the pistil (carpel), the female reproductive unit?

Stigma (receives pollen), style (stalk connecting stigma to ovary), and ovary (contains ovules).

What develops into the seed and what develops into the fruit after fertilization?

The ovule develops into the seed, and the ovary develops into the fruit.

Distinguish between a bisexual and a unisexual flower.

A bisexual flower has both androecium and gynoecium (e.g., hibiscus); a unisexual flower has only one of them - either stamens (male) or carpels (female).

What is pollination?

The transfer of pollen grains from the anther of a stamen to the stigma of a carpel.

Differentiate between self-pollination and cross-pollination.

Self-pollination: pollen transferred to the stigma of the same flower or another flower on the same plant. Cross-pollination: pollen transferred to the stigma of a flower on a different plant of the same species.

Name four agents of pollination.

Wind (anemophily), water (hydrophily), insects (entomophily), and birds (ornithophily).

List two characteristics of insect-pollinated (entomophilous) flowers.

They have large, brightly coloured, scented petals with nectar, and sticky/spiny pollen grains with sticky stigmas. (Any two)

List two characteristics of wind-pollinated (anemophilous) flowers.

They are small, dull, often unscented with no nectar; produce large amounts of light, dry pollen; and have feathery stigmas and versatile anthers. (Any two)

Give two advantages of cross-pollination.

It introduces variation and produces healthier, more vigorous offspring with greater adaptability; new and improved varieties can be created. (Any two)

What is fertilization in flowering plants?

The fusion of the male gamete (from the pollen grain) with the female gamete (egg) in the ovule to form a zygote.

What happens after a pollen grain lands on a compatible stigma (pollen tube formation)?

The pollen grain germinates and grows a pollen tube down through the style into the ovary, carrying the male gametes to the ovule (micropyle).

What are the main parts of a seed?

The seed coat (testa and tegmen), the embryo (radicle, plumule, and one or two cotyledons), and stored food (in cotyledons or endosperm).

Differentiate between a dicotyledonous and a monocotyledonous seed.

A dicot seed has two cotyledons (e.g., gram, bean) and food usually stored in cotyledons; a monocot seed has one cotyledon (e.g., maize) with food stored in the endosperm.

In a seed, what do the radicle and plumule develop into?

The radicle develops into the root, and the plumule develops into the shoot.

What is the function of the micropyle in a seed?

It is a small pore through which water enters the seed during germination and through which the radicle emerges first.

What is germination, and what are the three essential external conditions for it?

Germination is the sprouting of a seed into a young seedling. The three conditions are water (moisture), suitable temperature (warmth), and oxygen (air).

Differentiate between epigeal and hypogeal germination.

In epigeal germination the cotyledons are pushed above the soil due to elongation of the hypocotyl (e.g., bean, castor); in hypogeal germination the cotyledons remain below the soil as the epicotyl elongates (e.g., maize, pea, gram).