Question 11 : Photosynthesis takes place faster in
1. yellow light
2. white light
3. red light
4. darkness
View Answer   Discuss with Members

Question 12 : Nitrogen is fixed in ecosystems in ways stated below. Which one of the statements below is false?
1. By cyanobacteria
2. By electrical discharges in the atmosphere
3. By industrially synthesised fertilizer
4. By denitrification
View Answer   Discuss with Members

Question 13 : Mutation is
1. a factor responsible for plant growth
2. a change which affects the offspring of F₂ generation only
3. a change that is inherited
4. a change which affects the parents
View Answer   Discuss with Members

Question 14 : Plants are killed in winter by frost
1. because of desiccation and mechanical damage to the tissues
2. because no photosynthesis takes place at such low temperature
3. because respiration ceases at such low temperature
4. because there is no transpiration
View Answer   Discuss with Members

Question 15 : Potato is a modified form (outgrowth) of
1. root
2. stem
3. fruit
4. leaf
View Answer   Discuss with Members

Question 16 : Plants that grow under average temperature and moisture are called
1. halophytes
2. hydrophytes
3. mesophytes
4. xerophytes
View Answer   Discuss with Members

Question 17 : Phloem is a tissue found in
1. reproductive organs of animals
2. plants
3. insects
4. mammals
View Answer   Discuss with Members

Question 18 : Most of the red, blue and purple colours of plants are due to a pigment called
1. anthocyanin
2. carotene
3. chlorophyll
4. xanthophylls
View Answer   Discuss with Members

Question 19 : Ordinary table salt is sodium chloride. What is baking soda?
1. Potassium chloride
2. Potassium carbonate
3. Potassium hydroxide
4. Sodium bicarbonate
View Answer   Discuss with Members

Question 20 : Organic Substances which, in very small amounts, control growth and development called
1. vitamins
2. hormones
3. enzymes
4. None of the above
View Answer   Discuss with Members