Fibre to Fabric — Science STD 7 — Question

What happens during increased physical activity?

List the substances which pollute the soil.

Which is the ultimate source of energy for all living organisms?

How Woollen clothes keep us warm in winter?

Name the type of blood vessels which carry blood from organs to the heart.

What happens if an animal dies in the forest?

Mark the following statement as True or False. Correct the false statement.
Frogs can breathe through their skin as well as lungs.

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Boiling water in an open pan

Air __________ on heating.

Dip some crushed red rose petals in warm water to make the extract. Add a few drops of an acid and a base separately in two different containers. Write the effect of it on acid and base.