Monday 20 May 2013

3.21 understand that the sex of a person is controlled by one pair of chromosomes, XX in a female and XY in a male

One pair of chromosomes (out of 23 pairs) controls the gender of a person. XX is female; XY is male.

3 comments:

  1. The Biology Syllabus has changed…

    Here is a New blog for the 2017 Syllabus:

    http://igcse-biology-2017.blogspot.hk

    ReplyDelete
  2. more at

    http://igcse-biology-notes.blogspot.hk/2017/06/321-understand-that-sex-of-person-is.html

    ReplyDelete