VCAA 2010 paper help

[Zahta]

their is a question in 2010 vcaa and it says what name is given to a small group of colonising individuals i said founder effect and their is a question after it saying explain how the new and old colonies become seprate i said theirs no gen flow but also the new colnoie has selection pressure and less of allel frequecy  and their is no varation, i used better terms then that but

in the answer it says natural selection and all this other stuff dont know if what im saying is incorrect and i have a hard time with these questions .


Also can someone help me with question 5b 2010 unit 4

Why was the inactivation of one of the centromeres a significant step in human evolution?
Honestly i said its signification due to mitosis  or something and i was wrong , but like i dont get what they mean

[anjie123]

Due to the inactivation of one centromere, meiosis can occur.

(Remember that when the chromosomes separate to opposite poles of the cell during metaphase, they do it by breaking apart from the centromere. So if there were two centromeres, the chromosomes will split into 4 instead of just two, and you will end up with chromosomes that are like... halved twice o.O)

Since meiosis can occur, gametes can be formed, giving rise to humans!!

[zool3]

great response! i had that trouble too