In male cockroaches, sperms are stored in which part of the reproductive system?

Study the four statements (A - D) given below and select the two correct ones out of them :

A. Definition of biological species was given by Ernst Mayr.

B. Photoperiod does not affect reproduction in plants.

C. Binomial nomenclature system was given by R. H. Whittaker.

D. In unicellular organisms, reproduction is synonymous with growth.

The two correct statements are

Choose the correct statement.

Match Column-I with Column-II for housefly classification and select the correct option using the codes given below :

Column-I Column-II

a. Family (i) Diptera

b. Order (ii) Arthropoda

c. Clsass (iii) Muscidae

d. Phylum (iv) Insecta

Which of the following sets of diseases is caused by bacteria?

The highest DDT concentration in aquatic food chain shall occur in