What are homologous pairs of chromosomes?

Question

What happens to the homologous pair of chormosomes during meiosis? And why is it that after meiosis there is only one chromatid in each gamete? How will this gamete make a homologous chromosome with only one chromatid?

Answer 1

Homologous chr. are those that contain information for the same characters, one coming from the father and the other form the mother. During meiosis, there are two actual divisions (first one of the two chr. will go to one pole and the other one to the opposite pole. Second, each chr. is separated and each of the two chromatides goes to one pole). During meiosis, from a pair of homologous chromosomes (2 chromosomes, 4 chromotadis) there are 4 new cells formed. These cells are the sexual cells (eggs and spermatozoids). When two sexual cells join together (egg and spermatozoid), these two chromatids join. You can not forget that the first step when entering meiosis is to duplicate the DNA (for that moment a diploid organism becomes tetraploid)/ I hope it helps!!

Answer 2

Homologous chromosomes are the pair of chromosomes with genes for the same characteristics: one from the mother and one from the father.

During meiosis I the homologous chromosomes line up with each other and separate into the two different cells. During meiosis II the double-stranded chromosomes split to send one chromatid into each daughter cell which is a gamete.

When gametes join (an egg and a sperm join to make a zygote) the chromosomes from both parent are put into the same cell -- so the zygote has two of each kind of chromosome.

Answer 3

One "set" of chromosomes = haploid number of chromosomes. The chromosomes in a given species's set are all structurally different from each other, and are numbered: 1, 2, 3 etc. Diploid cells have 2 sets: two 1's, two 2's, etc. In a diploid cell, the 1's are a homologous pair, the 2's are a homologous pair. Because one chromosome 1 is homologous (structurally alike) to another chromosome 1. So the diploid number ("2n") is just twice the haploid number ("n"). For 2n = 48, n =24. There are 24 chromosomes in the set, so there are 24 homologous pairs.