Biology Past Questions and Answers

In a water culture experiment, the culture solution in a transparent beaker turned green. What precaution<br/>should have been taken to prevent the culture solution from turning green?

A Changing the culture solution regularly
B Increasing the number of times the culture is aerated
C Covering the transparent beaker with black cloth
D Adding warm alcohol to bleach the green colour
E Sterilizing the beaker in a hot oven before use

Question 4077:

Which of the following is responsible for the conversion of nitrites to nitrates in the nitrogen cycle?

A Denitrifying bacteria
B Nitrifying bacteria
C Lightening
D Fungi
E Brown algae

Question 4078:

Hydra captures small crustaceans by means of

A Pseudopodia
B Musculo-epithelial cells
C Tentacles
D Enteron
E Ectoderm

Question 4079:

Which of the following processes is not due to interaction between the biotic and abiotic components of an<br/>ecosystem?

A Soil nutrient depletion
B Condensation
C Decomposition
D Osmosis
E Photosynthesis

Question 4080:

The entire habits and habitat of an organism can be described as its

A Ecological community
B Ecological niche
C Habitat factor
D Biotic factor
E Abiotic factor