Reproduction: How Life Continues: 17 MCQs with answers

Reproduction

Reproduction is the biological process by which living beings produce new individuals of their own kind, keeping life continuing on Earth.

A stem piece of Plant B is fitted into it

In grafting, a stem piece of Plant B is inserted and fitted into the slit made on Plant A, and the joint is protected until it heals.

Spores are lightweight and float through air currents

Spores are lightweight, usually single-celled, and float easily through air currents, waiting for moisture and nutrients to germinate.

Louis Pasteur

Experiments by Louis Pasteur proved that new life always comes from pre-existing life. He also found the germ theory of disease and strengthened the cell theory.

Bryophyllum leaves sprouting tiny plantlets

Bryophyllum leaves sprout tiny plantlets which eventually grow into new plants. This is an example of vegetative propagation, where new plants arise from the vegetative parts of a plant.

True

The central process behind asexual reproduction is mitosis, a type of cell division that produces two daughter cells, each having the same number of chromosomes identical to the parent cell — which is why asexual offspring are called clones.

Tissue culture using the shoot tip

Tissue culture uses the shoot tip (apical meristem) to mass-produce healthy plantlets that are genetically identical to the parent, and it has revolutionised banana farming.

Budding

In yeast, small round outgrowths called buds emerge from the parent cell. This process is called budding.

Pollination

Cutting, grafting, layering, and tissue culture are methods of vegetative propagation. Pollination is part of sexual reproduction in plants.

Spores already present in the air settle on the moist bread and grow

The mould grew from spores already present in the air, which settled on the moist bread and began reproducing rapidly. Louis Pasteur proved that new life always comes from pre-existing life.

Budding in hydra

Hydra is a simple multicellular animal that reproduces asexually by budding, where a bud forms on the parent body and separates to live independently.

Mitosis, producing two daughter cells with the same number of chromosomes as the parent

The central process behind asexual reproduction is mitosis, a type of cell division that produces two daughter cells, each having the same number of chromosomes identical to the parent cell.

Both A and R are true, and R correctly explains A.

Asexual reproduction uses mitosis, which produces daughter cells with the same number of chromosomes as the parent. Because of this, the offspring are genetically identical to the parent and are called clones.

Cut the twig from the parent plant

In layering, once roots have developed from the buried part of the twig, the twig is cut from the parent plant so that it can grow as a new plant.

The mould came from spores present in the air that settled on the damp wall.

Moulds grow from spores already present in the air, which settle on moist surfaces and begin reproducing. Louis Pasteur proved that new life always comes from pre-existing life, not from non-living matter.

Because the offspring are genetically identical to the parent and retain its desirable qualities

Asexual reproduction produces genetically identical individuals. This enables farmers to cultivate desirable crops on a large scale, ensuring that a plant with good fruit, yield, or disease resistance passes those exact qualities to the next generation.

Tissue culture, which allows for the mass production of genetically identical plantlets from a single parent.

Tissue culture is the most suitable method because it allows for the production of genetically identical plantlets from the shoot tip of a single parent. This ensures that the new mango trees will inherit the desirable traits of the original tree, maintaining uniformity and health across the crop.