Question

Compare and contrast properties of sister chromatids and homologous chromosomes.

Answer 1

Answer:

Explanation:

Sister chromatids are regarded as replicated chromosomes. Sister chromatids are two identical copies of chromosomes held at the centromere that are formed as a result of replication. They are identical in the sense that they contain same alleles/gene sequence of the same genes.

Homologous chromosomes, on the other hand, are similar (in length, centromere position) but non-identical chromosomes. Homologous are non-identical in the sense that they may contain different alleles of a gene and are received from each parent. homologous chromosome contain four chromatids; two of which are sister chromatids and non-sister to the other two.

Both undergo meiosis where homologous chromosomes separate in meiosis I while sister chromatids separate in meiosis II but only sister chromatids undergo mitosis.

Answer 2

Answer:

Homologous chromosomes

Basically at fertilization, sperm and oocyte from the mother provided each chromosome ,The pair of chromosome that emerged from the diploid cell formed is called homologous chromosomes. They contain exactly alike in structure, with the same genes and the same gene loci on the chromosomes..But   the allele of the genes may not be the same and their  DNA sequence are  different.

At metaphase of meiosis I they formed a bivalent, at Synapsis. Crossing over of genetic materials takes place at the point chiasmata, and this results in genetic variation. Homologous chromosomes  are pulled apart at Anaphase 1 of meiosis and into  chromatids   at   Anaphase   II.

Sister Chromatids

These are the products of  a single chromosome replication during   S-phase of interphase.  That  is  one half  of  each copy of the chromosome replicated. They contain the same genetic composition and same  sequence of DNA;and are joined together at common centromere,

They are separated from each other at Centromere ( unlike in homologous chromosomes at synapsis,) in  metaphase  of  mitosis. But the separation takes place at   Anaphase ii of second meiotic division  in meiosis.

When they paired together they form dyad, unlike bivalent  formed by Homologous chromosomes.

Explanation: