Acids, Bases and Salts — Science STD 7 — Question

Which part of the digestive canal is involved in:
Chewing of food _____________.

Name the elements determining weather of a place.

Mention the mode of reproduction in the following organisms.
(i) Spirogyra
(ii) Yeast
(iii) Money plants

What does a substance turning blue litmus paper red indicate?

What term is used for the following process? Washing of sheep’s fleece to remove dust, dirt, dried sweat and grease.

Changes listed in A, B and C are as follows :
A. Creating some objects with paper: When we create different objects like aeroplane, boat, bird, etc. by folding a sheet of paper, only shape and size changes. We can get back the original sheet by unfolding it again.
B. Playing with a balloon: When we loosen the grip of the inflated balloon we get the original shape of balloon back, and we can inflate it again but when we prick the inflated balloon with a pin, it gets deflated with a hole in it, so we cannot able to inflate it again.
C. Crushing a piece of chalk: When we crushed a piece of chalk to powder form, we cannot can get back the original piece of a chalk.

State the consequences, if plants do not get enough water.

Which cell organelle is a site for cellular respiration?

Why does hot air rise?