Compare sister chromatids to homologous chromosomes.

Sister chromatid is the 2 part of the same chromosome. Joined together with centromere They are the copy of one another.

for example: Allele for black hair, allele for black hair (exactly same)

Homologous chromosome is the 2 corresponding chromosome from different parent that may having different alleles.

For example: Allele for black hair, Allele for blue hair. (both are for hair, but are slightly different)

Brainliest please~

is called echinoderms