The Invisible Living World: Beyond Our Naked Eye MCQs for UPSC Prelims

Dried fish and sun-dried papads can be stored for months without spoiling, while the same materials spoil within days when moist. The best explanation is that

1. A sunlight leaves behind a coating that no organism can cross
2. B microorganisms need moisture to grow, and drying takes that moisture away
3. C dried food contains no nutrients that anything could feed on
4. D dry food is too hard for microorganisms to settle upon

Bread dough mixed with yeast and kept in a warm place doubles in size. The rising is caused by

1. A a gas produced by the yeast, which is trapped as bubbles in the dough
2. B water being pulled into the dough from the warm air
3. C the yeast grains swelling up until they fill the bowl
4. D the flour changing into a lighter kind of flour

Which of these is a group of microorganisms?

1. A Birds
2. B Bacteria
3. C Ferns
4. D Insects

The smallest unit from which the body of every living organism is built is the

1. A organ system
2. B tissue
3. C organ
4. D cell

Which list arranges the levels of organisation from the smallest to the largest?

1. A Organ, cell, tissue, organ system
2. B Cell, tissue, organ, organ system
3. C Organ system, organ, tissue, cell
4. D Tissue, cell, organ system, organ

Damp bread kept inside a closed box still grows mould after a few days. The mould has come from

1. A the plastic of the box turning into mould
2. B fungal spores already present on the bread and in the air inside the box
3. C the water alone, with no living thing involved
4. D nothing at all, since mould appears on its own