CONVECTION

Hot water (less dense) eises to the top while the cold water (denser) descends to the bottom.

- Heat flows in water ( and gas) through convection.

HEAT TRANSFER THROUGH A SOLID

Heat is transfer from a hot end to a cold end of a rod through conduction.

The nearest thumtack from the flame drops first, followed by the others.

SUPPORT SYSTEM IN AQUATIC PLANTS

Aquatic plants stand erect in water because they are supported by the buoyancy of water.

This can be demonstrated by the activity below:

Plant in a beaker without water

In water, plant can stand upright.

FORM 1 (ANSWER - REVISION CHAPTER 7)

1C 2A 3C 4D 5D 6B 7D 8C 9D 10C

11C 12A 13D 14A 15C 16A 17A 18D

19A 20A 21A 22A 23A 24C 25A

26A 27A 28D

FORM 2 - ANSWERS (CHAPTER 8)

Ojective
1A 2A 3D 4D 5C 6C 7D 8A 9B 10D 11B 12A 13D 14C

SUBJECTIVE
1. a) Endosjeletn - sparrow, bear, hamster
Exoskeleton - oyster, crab, prawn
Hydrostatic skeleton - jelly fish, caterpillar, starfish

b) 1. to support body weight
2. to maintain the shape of the body
3. to protect the soft internal orgns
4. to enable movement

2. a) butress root
b) Prop root
c) Claping root
d) Tendrils
e) Stilt root
f) prickles

STEPS TO TEST PRESENCE OF STARCH IN THE LEAF

1. Boil pieces of leaves in a beaker of water TO KILL THE CELLS AND BREAK THE WALL OF LEAF CELL



Fresh leaves

Boiling the leaves

2. Heat the pieces of leaf in alcohol for few minutes TO REMOVE CHLOROPHYLL

Alcohol turns to green color- chlorophyll is removed



3. Soak the pieces of leaf in hot water for a little while TO SOFTEN THE LEAF




4. Using a dropper, add a few drops of iodine solution onto the pieces of leaf TO TEST FOR STARCH

STUDENTS OBSERVING THE LEAVES



LEAVES THAT CONTAINS STARCH TURN TO DARK BLUE COLOUR