Question

Dyad is a pair of
A. Sister chromatid
B. Non-sister chromatids
C. Homologous chromosomes
D. Non-homologous chromosomes

Answer 1

Hint:The dyad can be found during the anaphase I stage of the Meiosis at a process called a disjunction. The tetrad migrates into the opposite poles of the cell as they are divided into two, which are the dyads.

Complete answer:The chromatids maybe a sister or non-sister chromatids. A sister chromatid is either one of the two chromatids of the same chromosome joined together by a common centromere. A pair of the sister chromatids is called a dyad. Once the sister chromatids have separated during the process of anaphase of the mitosis or the anaphase II of the meiosis during the sexual reproduction, they are again called the chromosomes, each having the same genetic mass as one of the individual chromatids that made up its parent. The DNA sequence of two sister chromatids is completely identical.
The sister chromatid exchange is the exchange of genetic information between the two sister chromatids. The SCEs (sister chromatid exchange) can occur during the process of mitosis or meiosis. The SCEs appears to primarily reflect DNA recombinational repair processes responding to the DNA damage.
The non-sister chromatid refers to either of the two chromatids of the paired homologous chromosomes, also the pairing of a paternal chromosome and a maternal chromosome. In the chromosomal crossovers, the non-sister chromatids form the chiasmata to exchange the genetic material during the prophase I stage of the meiosis.

Therefore, the correct answer is option A.

Note:The primary function of sister chromatids is to pass on a complete set of the chromosomes to all the daughter cells formed as a result of the cell division. Also, sister chromatids play an important role in maintaining the integrity of the genome by being involved in DNA repair.