Male has sex chromosomes: One X + one Y
Female has sex chromosomes: Two X
So, Female must contribute by one X chromosome, but male can contribute either by X or Y, if he sends, X chromosome, then Female (Girl) will form, but if he sends Y chromosome, then Male (Boy) will form
Hope this helps!
The best evidence of such phenomena could be a population's genetic variation decrease.
When a population bottleneck occur it means that for some reason (i.e. environmental events) the size of a population is largely reduced. This leads to reduction of the genetic variation in that new smaller population. When a bottleneck occur, the founder effect is normally seen, which is that one population is established by a small group of a previously larger population leading once again the genetic variation, now though with a bigger population, to be very reduced.
I think the answer is NUCLEUS.
Hope it helps!
Virions are composed largely of nucleic acids and protein. In order to produce more virions, the host cell must synthesize more of these parts through NA replication and protein synthesis.
