Sister chromatids are identical forms of chromatids of a chromosomes. They are mostly formed by semi-conservative replication of DNA molecule of a single chromosome.Thus they are like 'photocopies' of original parent chromosomes; joined together at the Centromere.

They are exactly similar in all ramification; with the same gene and allele compositions..

However; slight differences arise between the two identical sisters due to mutation from errors at replication;and also in the length of telomere repeats.

Non-sister chromatids are dissimilar forms of chromatids of a chromosomes formed when each half of a chromosome at fertilisation from separate haploid sex-cells, of each parent. fused.They contain different genetic composition;because they are not on the same homologous chromosomes.Therefore crossing -over ensure variation.

However, they are genetically similar in composition; if they are contained in homologous chromosomes. This is because Synapsis of bivalent of these chromosomes allow genetic material to be shared by chromosomal crossing-over between the non-sister chromatids on the chromosomes ; therefore identical genetic characteristics are shared .

Explanation:

7 0

3 years ago

What is this please some one help .

andriy [413]

Answer:

75%

Explanation:

Dominant means more. 100% is all so like all black. 50 is half-half which is wrong because its supposed to be more. 25% is wrong because its "more" so it has to be 75%

Hope this helps :D Please mark brainliest if correct D:

3 0

3 years ago