To increase genetic diversity in offspring, homologous pairs in prophase i, and in anaphase i

To increase genetic diversity in offspring, homologous pairs cross over in prophase I, and separate to different cells in anaphase I.

Meiosis is very complicated cell division and out of that, prophase I is the most complicated sub step. Prophase I has five sub divisions namely Leptotene, zygotene, pachytene, diplotene and diakinesis. In these five steps, the chromosomes split into their sister chromatids which remain attached at the centromere. The homologous pair of chromosomes come together and they share a random part of their DNA content with their sister counterpart, which in turn changes the genetic pattern and mixes characters of both father and mother. This is called crossing over.

Now the 2 homologous chromosomes lie on two planes in the centre of the cell and spindle fibres get attached to the centromeres of these chromosomes and they are pulled apart to different poles. The sister chromatids don't separate, the whole chromosome is pulled, so the chromosome number becomes halved. This is called reduction division or separation.

answer; ///(b) it is composed of four protein chains and four heme groups;

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .