The Fundamental Unit of Life — Science STD 9 — Question

When a car runs on a circular track with a uniform speed, its velocity is said to be changing. This is because:

1. The car has a uniform acceleration.
2. The direction of car varies continuously.
3. The car travels unequal distances in equal time intervals.
4. The car travels equal distances in unequal time intervals.

Set up an experiment to demonstrate the effect of low pressure and particulate nuclei over water vapours.

1. Of a mixture of several frequencies.
2. Of mixture of only two frequencies.
3. Of a single frequency.
4. Always unpleasant to listen to.

Which one is made of dead cells?

1. Sclerenchyma
2. Tracheids
3. Vessel
4. All the above

Green plants in an ecosystem are called:

1. Producers.
2. Consumers.
3. Decomposers.
4. None of the above.