9.2.1 The Abiotic and Biotic Components of the Environment (Structured Question 1 & 2)

Question 1:
R, S and T in Figure below show three types of interactions between organisms.

Name the type of interaction represented by R and S.

Describe the interaction represented by R.

In the interactions represented by S and T, what terms are used to describe organisms X and Y?

State one characteristics of organism X that adapts it for the interaction.

The rubber tree in the interaction represented by S dies.
Explain what will happen to organism X.

Saw dust can be used in the interaction represented by T for the commercial cultivation of mushrooms.
Explain how mushrooms can grow on saw dust.

Organism R: Mutualism/ symbiosis
Organism S: Commensalism

Nitrogen-fixing bacteria in the root nodules fix nitrogen to form ammonia which is used by the plant while Rhizobium bacteria get shelter from the plant.

X: Epiphyte
Y: Saprophyte

The presence of aerial roots which absorb moisture from the air

X continues to grow because it photosynthesises.

Mushrooms grow on dead organic matter.
Mushrooms secrete enzymes which digest the complex organic matter to simple substances.

Leave a Comment