<span>The sex cells, more scientifically known as the ova and spermatozoa, are composed of 23 of the usually 46 human chromosomes. They have half the usual number because they of course combine to form a new, genetically distinct, cell, termed the zygote. The correct term for this type of cell, one with half of the complete genome, is GAMETE. Therefore the answer is option (a).</span>
I think the answer is (C). I hope this helps! :)
Answer:
Blastocyst is an early embryonic stage in mammals otherwise it is a blastula which is followed by development of gastrula. Blastocyst is a hollow ball like structure that develops by repeated cell division from zygote . It is superficially covered by a layer of cells collectively termed trophoblast.
Explanation: