NCERT Solutions for Class 9th Science Chapter 11 .1 Asexual Reproduction — In-text Questions

Book page 21111 Updated on2026-09-08

Q1.

Are there other methods of asexual reproduction in organisms?

Answer

Yes. Budding is only one of several. All of them share the same core — a single parent and cell division by mitosis — and differ only in how the parent body is divided up.

Method	What happens	Organisms named in this chapter
Binary fission	The parent cell divides into two nearly equal daughter cells	Bacteria, amoeba
Budding	An outgrowth forms at one spot, grows and separates	Yeast, hydra
Spore formation	Millions of light spores are made in a sac or on a vesicle and released into the air	Rhizopus, Aspergillus and other fungi
Vegetative propagation	A new plant grows from a stem, leaf or underground part of the old one	Potato, ginger, money plant, sugarcane, Bryophyllum

Why they are all called asexual: not one of them involves a gamete or a fusion of two cells. The chromosome number is never halved and never restored — it simply stays the same at every division, because mitosis gives each daughter cell the same set as the parent. That is why every product is a clone.

Q2.

You have learnt that food like fruits get rotten by microbes (fungi). Where else do we find these microorganisms?

Answer

Almost everywhere — wherever there is moisture, warmth and something organic to feed on. The chapter itself points to several of these places.

In the air. Spores drift on air currents. This is the source that seeded your bread in Activity 11.3.
On cooked food left out. A day on the kitchen counter in warm weather is enough for a smell and fuzzy patches to appear.
On damp walls. The black patches so often seen in the monsoon are fungal colonies.
In soil and in manure heaps. Fungi there break down dead leaves, straw and dung — this is how compost forms.
On rotting fruit and vegetables, on old leather and damp clothes, and on our own skin and inside our gut.

Why they are so widespread: a spore is lightweight and usually single-celled, so even a slow air current lifts it. Millions are released from a single mould colony, so the air over any inhabited place always carries some. They do not need to stay alive and active while travelling — a spore can wait, dry and dormant, until it lands somewhere moist and nourishing, and only then germinate.

Q3.

Where do these microorganisms come from?

Answer

From other living microorganisms — from spores and cells that were already present in the air, in dust, in water or on the surface. They are never produced by the non-living food itself.

Why we are sure: for a long time people believed in spontaneous generation — that maggots arose from meat and moulds from bread. Louis Pasteur settled the question by experiment. He showed that a nutrient broth stays clear indefinitely if microorganisms from the air are kept out of it, and clouds over as soon as they are allowed in. So new life always comes from pre-existing life. From this came his germ theory of disease — that particular microorganisms cause particular diseases — and support for the cell theory, that all cells arise from pre-existing cells.

What follows from it in daily life: if microbes always come from outside, then keeping them out, or killing the ones already present, must preserve food and prevent infection. That is why we boil water, pressure-cook and sterilise surgical instruments, and why a hospital insists on sterile dressings.

Tip: notice how carefully Activity 11.3 is designed around this idea. The cotton and tissue are moistened with pre-boiled water, so the water carries no live microbes. Any mould that then grows on the bread can only have come from the air — the activity is a small Pasteur experiment of your own.

Was this helpful? Report an error