Biology
Assertion (A): Gambusia is a kind of fish which should be introduced in ponds. These fishes enhance the oxygen content of the water.
Reason: (R): Gambusia fishes selectively devour mosquito larvae from the ponds. Hence used to control the growth of mosquitoes.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.
Answer
A is False and R is True.
Reason — Gambusia is introduced in ponds not to increase oxygen content, but to control mosquito populations. They do not significantly enhance oxygen levels in water.
Gambusia are biological control agents used to eat mosquito larvae, helping prevent mosquito-borne diseases like malaria and dengue.
Related Questions
Identify the water-borne diseases based on their symptoms given below:
Water borne disease Symptoms P Yellowish eyes, dark yellow urine (due to bile pigments). Q Severe diarrhoea and vomiting followed by dehydration - P — Trachoma, Q — Hepatitis
- P — Trachoma, Q — Cholera
- P — Conjunctivitis, Q — Dysentry
- P — Hepatitis, Q — Cholera
Assertion (A): Malaria is caused by Plasmodium which is spread by Culex mosquito.
Reason (R): There are two hosts in the life cycle of a malarial parasite which are Anopheles mosquito and humans/monkeys/birds, etc.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.
Assertion (A): Bacillary dysentery is caused due to infection by a protozoan which occurs frequently in children.
Reason: (R): Shigella is a kind of bacillus bacteria which causes bacillary dysentery.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.
Assertion (A): Hygiene is defined as the science and practice of maintaining good health.
Reason: (R): Hygiene can be maintained by taking vaccines and antibiotics regularly to keep a person away from diseases.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.