Question

(i) Define and give the role of amniocentesis. 

(ii) Name the causative agent and give any one symptom of Gonorrhoea. 

(iii) What is the significance of dispersal of seeds? Give any two points. 

(iv) What are seasonal breeders? Give an example. 

(v) How is the chromosome number maintained in sexually reproducing organisms?

Answer 1

(i) Aspiration of amniotic fluid from amniotic sac around the foetus is called amniocentesis.

Role : Used to determine 

• To determine sex and sex abnormalities of developing baby. 

• Genetically controlled congenital diseases.

• Gene related metabolic disorders.

(ii) Causative agent – Neisseria gonorrhoeae 

Symptom – Pus containing discharge from genital ducts.

(iii) Significance of dispersal of seeds:

• Evolution of land plants. 

• In establishing species in new areas by means of dispersal.

(iv) Seasonal breeders are organisms that perform breeding and have active reproductive cycles during particular breeding season e.g.. Birds

(v) in sexually reproducing organisms. chromosome number is maintained by process of meiosis in which chromosome number is reduced to half which is restored on fertilization.