Read the given statements and select the option that correctly fi lls the blanks in any two of them.
(a) Zygote divides a number of times and forms a hollow ball like structure called (i)_______. It moves down and gets implanted in the uterus. It starts developing body parts and at this stage it is called (ii) ________.
(b) (iii) ________ is the period in life when a girl or a boy attains sexual maturity.
(c) Production of sex hormones is under the control of (iv) _________ gland.
(d) Metamorphosis in frog requires presence of (v) ________ in water to produce thyroxine hormone.
