BIOLOGY CH24 Environmental Science — Science STD 9 — Question

Define (a) oxidation (b) reduction reactions : Give examples.

What are reducing agents? Give examples.

Mention the properties of magnetic lines of force.

Higher Order Thinking Skill.

There are 3 plants A, B and C. The flowers of A open their petals in bright light during the day but closes when it gets dark at night. On the other hand, the flowers of plant B open their petals at night but closes during the day when there is bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object.

1. Name the phenomenon shown by the flowers of plant A and B.
2. Name one plant each which behaves like the flowers of plant A and B. 
3. Name the phenomenon exhibited by the leaves of plant C. 
4. Name the plant which behaves like the leaves of plant 'C'?

List out the characteristics of Dye.

What do you mean by uniform motion?

A metal ball of heat capacity 50J/°C loses 2000 J of heat. By how much will its temperature fall?

Describe the nature of images formed by plane mirrors.

Numerical Problem.

Calculate the apparent weight of wood floating on water if it weighs 100g in air.

Higher Order Thinking Skill.

Which are not true cells in the blood? Why?