A large quantity of urban sewage is drained to nearby village river. Which among the given conditions would happen after mixing of sewage into the river?
(i) Biochemical oxygen demand (BOD) of receiving water body increases.
(ii) Dissolved oxygen of receiving water body decreases.
(iii) It will not cause mortality among fishes and other aquatic creatures.
(iv) It will lead to nutrient enrichment of receiving water body.

(i), (ii) and (iii)

(i), (ii) and (iv)

(ii) and (iii)

(iii) and (iv)

Solution

(i), (ii) and (iv)

Sewage having biodegradable organic matter is released into water body, micro- organisms involved in biodegradation consumes lot of oxygen to decompose the sewage. This results in a sharp decline in dissolved oxygen downstream from the point of sewage discharge and hence increases biological oxygen demand (BOD).

Presence of large amount of nutrients in water causes excessive growth of planktonic algae known as algal bloom. It causes deterioration of water quality and fish mortality.

Some More Questions From Reproduction in Organisms Chapter

Which of the following statements is correct

Which of the following is a cloning vector?

Starting from the maximum, arrange the following male reproductive accessory organs in the correct order, based on the amount of secretion poured into urethra.
(i) Prostrate gland
(ii) Seminal vesicle
(iii) Bulbourethral gland

For Daily Free Study Material Join wiredfaculty

Reproduction In Organisms

Some More Questions From Reproduction in Organisms Chapter

Which of the following statements is correct

Which of the following is a cloning vector?

Starting from the maximum, arrange the following male reproductive accessory organs in the correct order, based on the amount of secretion poured into urethra.
(i) Prostrate gland
(ii) Seminal vesicle
(iii) Bulbourethral gland

Which of the following contraceptive devices make uterus unsuitable for implantation?

Sexual stage (gametocytes) of Plasmodium occurs in

Sporopollenin is a constituent of pollen exine. It can be degraded by the action of

The pollen grains of rice and wheat lose their viability inminutes of their release

After doble fertilization, a mature ovule has

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Location

For Daily Free Study Material Join wiredfaculty

Reproduction In Organisms

Some More Questions From Reproduction in Organisms Chapter

Which of the following statements is correct

Which of the following is a cloning vector?

Starting from the maximum, arrange the following male reproductive accessory organs in the correct order, based on the amount of secretion poured into urethra.(i) Prostrate gland(ii) Seminal vesicle(iii) Bulbourethral gland

Which of the following contraceptive devices make uterus unsuitable for implantation?

Sexual stage (gametocytes) of Plasmodium occurs in

Sporopollenin is a constituent of pollen exine. It can be degraded by the action of

The pollen grains of rice and wheat lose their viability inminutes of their release

After doble fertilization, a mature ovule has

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Starting from the maximum, arrange the following male reproductive accessory organs in the correct order, based on the amount of secretion poured into urethra.
(i) Prostrate gland
(ii) Seminal vesicle
(iii) Bulbourethral gland