For the first few weeks the baby sex is undermined, at 18 weeks you can see if the baby is a boy or girl! So it takes about 18 weeks for a penis to develop. If you meant when the penis starts to grow is in between the ages of 7 to 11 years old and it wont be fulling formed until they are at least 18 to 21 years old.
Answer:
The correct answers would be maintain chromosome number through generations and cause genetic variations by recombination.
In Meiosis a cell divides into four daughter cells all of which have half the number of chromosomes present in a parent cell.
It helps in the formation of gametes in sexually reproducing organisms.
These gametes (one from father and one from mother) fuse together to form a zygote. It re-established the chromosomal number as that of the parent.
In absence of meiosis, the chromosomal number would have doubled after each generation.
In addition, the meiosis also increases the genetic variation among the population with the help of crossing over which occurs during the pachytene stage of prophase I.
During this event, genetic information is exchanged between the non-sister chromatids of the homologous chromosomes. It produces a new combinations of genes that are different from either parent.
Ribosomes are the site of translation of strands of transferRNA into chains of amino acids. Ribosomes allow the reading of the genetic information coded for by the tRNA which codes for the position of amino acids along a protein
