Ram's teacher was showing the structure of a cell under a compound microscope,highlighting different parts like the cell wall,cell membrane,and nucleus. The teacher explained the difference between plant and animal cells,noting that the cell wall is found only in plant cells. Everyone observed the structure carefully and understood its structural importance.
$(a)$ What kind of qualities are shown by Ram?
$(b)$ Why is the cell called the structural and functional unit of life?

An Italian bee variety $A. mellifera$ has been introduced in India for honey production. Write about its merits over other varieties.

Ravjot's mother always squeezes water from wet clothes in the spinner of a washing machine and then uses it to clean the floor:
$(a)$ Write the principle of the technique used in the above-mentioned process.
$(b)$ Write one more application of this technique.
$(c)$ What do you learn from Ravjot's mother?

Dalton was the first scientist to use symbols for elements. Chemical symbols act as a vocabulary of chemical language. Chemical symbols are used to describe chemical changes with clarity and precision. Chemical symbols help in identifying specific elements. Chemical symbols also represent an atom of a particular element. Chemical symbols also signify the atomic mass of an element.
$(a)$ How do symbols help in identifying specific elements?
$(b)$ How do we use symbols in daily life for our convenience?
$(c)$ What values do you find in using symbols?

Write two examples each of the fishes that are:
$(i)$ Top dwellers
$(ii)$ Middle dwellers
$(iii)$ Bottom dwellers,in composite fish culture.

How is a fumigant different from a pesticide? Name one natural substance which can be used in place of a fumigant.