Thursday, 22 November 2012

3.3 Natural Defense in Plants

1) Plants have specific characteristics to protect themselves from being eaten or damaged by their predators.

2) The predators of plants are humans and animals.

Folding leaflets

1) Mimosa plants fold their leaflets when touched. The thorns are exposed.



1) Papaya trees, jackfruit trees, yam plants and rubber trees produce latex in their stems, leaves and fruits.

2) The latex can cause itchiness which keeps away animals which eat them.

                                                         Rubber tree                                        Yam plant


1)The fruit, stems and leaves of certain plants are covered with sharp thorns.

2) The thorns can hurt animals which try to eat or destroy the plants.

3) Examples: bougainvillaea, rose, cactus, pineapple, aloe vera, mimosa.

                                                Cactus                                                          Rose
Poisonous substances

1) The sap and fruit of the pong-pong tree are poisonous to humans and animals.

2) Some types of mushrooms are poisonous.


Fine hairs

1) The stems and leaves of bamboo, sugar cane and pumpkins are covered with the fine hairs.

2) The fine hairs cause itchiness to animals which come into contact with them.

                                   Pumpkins                                                                       Bamboo trees