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

Book page 21211 Updated on2026-09-08

Q1.
Do you observe thread-like structures with a round sac at the tip? Do you also see tiny round structure (spores) inside the sac?
Answer

Yes to both. The thread-like structures are the hyphae, the round sac at the tip of an upright hypha is the sporangium, and the tiny round bodies packed inside it are the spores.

StructureWhat it looks likeWhat it does
HyphaeFine branched threads spreading over and into the breadSecrete enzymes onto the bread, digest the starch and absorb the products — this is how the fungus feeds
Upright stalkA single hypha standing up from the matLifts the sac clear of the surface into moving air
Sac (sporangium)Round, dark, pin-head sizedEncloses and protects the spores until they are ready
SporesTiny round bodies, usually one cell eachDispersal and reproduction — each can germinate into a whole new mould
Why this is asexual reproduction: a spore is made by mitosis from the parent mould alone. It is not a gamete, it fuses with nothing, and the mould that grows from it carries exactly the parent's chromosome set. One parent, mitosis, identical offspring — the definition of asexual reproduction.
Q2.
Where did the mould on your bread slice come from? It was not present when the bread was fresh.
Answer

From spores that were already floating in the air of the room. They settled on the moist bread, found warmth and nutrients there, and germinated. Nothing was added to the box except bread, cotton, tissue and boiled water — so the air is the only possible source.

spores from one mould colony ≈ millions
each spore: usually single-celled and lightweight
→ carried far and wide by ordinary air currents
Why they were invisible and then suddenly obvious: a single spore is a few micrometres across, far too small for the eye. It stays dormant while it is dry. The moment it lands on something moist and nourishing it germinates, sends out a hypha, and the hypha branches again and again. What you finally see after three days is not one spore but a colony of millions of cells built from it — which is why the growth seems to appear "out of nowhere".
Did you know? The same thing happens on rotting fruit and in a manure heap, as the chapter notes. And it is a mixed blessing: fungi spoil our food, but the same fast spore-based multiplication lets them break down organic waste and pollutants, remove heavy metals from industrial waste, and give us antibiotics such as penicillin and amoxicillin.
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