Structure of the Atom — Science STD 9 — Question

i. Suppose the mass of the earth somehow increases by 10% without any change in its size. What would happen to your weight?
ii. Suppose the radius of the earth becomes twice of its present radius without any change in its mass. What will happen to your weight?

Draw a plant cell and label the parts which
i. determines the function and development of the cell
ii. packages materials coming from the endoplasmic reticulum
iii. provides resistance to microbes to withstand hypotonic external media without bursting
iv. is site for many biochemical reactions necessary to sustain life.
v . is a fluid contained inside the nucleus

Differentiate between a saturated and an unsaturated solution. How will you test whether a given solution is saturated or not?

What is air pollution? How is it caused? Give its effects.

How are sol, solution and suspension different from each other?

Write the modes by which insects affect the crop yield.

Give a brief account of cartilage.

Name major phyla of Animal kingdom. Write down one character and one example of each of them.

i. State what will happen when human red blood cells are placed in a hypotonic salt/sugar solution.
ii. Why plant cell shrinks when kept in a hypertonic solution.
iii. Why lysosomes are known as suicidal bags?

Describe an activity of determine the boiling point of water and melting point of ice.