How many secondary spermatocytes are required to form 400 million spermatozoa?
Arrange the components of mammary gland. (from proximal to distal).
(a) Mammary duct
(b) Lactiferous duct
(c) Alveoli
(d) Mammary ampulla
(e) Mammary tubules
Choose the most appropriate answer from the options given below :
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): During pregnancy the level of thyroxine is increased in the maternal blood.
Reason (R): Pregnancy is characterised by metabolic changes in the mother.
In the light of the above statements, choose the most appropriate answer from the options given below:
Which of the following statements are true for spermatogenesis but do not hold true for Oogenesis?
(a) It results in the formation of haploid gametes
(b) Differentiation of gamete occurs after the completion of meiosis
(c) Meiosis occurs continuously in a mitotically dividing stem cell population
(d) It is controlled by the Luteinising Hormone (LH) and Follicle Stimulating Hormone (FSH) secreted by the anterior pituitary
(e) It is initiated at puberty
Choose the most appropriate answer from the options given below :