$A$ : In morula stage the cells divide without any increase in size.
$R$ : Zona pellucida remains intact till cleavage is completed.
Assertion and Reason both are correct and also correct explantion.
Assertion and Reason both are correct but not explanation of assertion.
Assertion is correct, but Reason is incorrect.
Both Assertion and Reason are incorrect.
Normally the number of chromosomes in the nuclei of gametes that fuse at fertilization are
Fertilisation of an egg cell it means......
$(1)$ End of process of oogenesis
$(2)$ Induces the completion of the second meiotic division
$(3)$ The corpus luteum degenerates
$(4)$ Signals for maintain progesterone level in blood
$(5)$ Formation of zygote
In which stage is blastocoele formed
The point of sperm entry during fertilization forms
When sex is determined at the time of fertilization, it is known as