Answer:
The correct answer is --Homologous chromosomes contain the same genes, but may contain different alleles. Sister chromatids contain the same genes and the same alleles.
Explanation:
Sister chromatids are the identical copies formed during the synthesis phase of the cell cycle that means both the sister chromatids share the same allele of a gene at the same locus on the chromosome. These sister chromatids are joined together by a centromere.
Homologous chromosomes are the set of chromosomes in which one chromosome comes from male parent and another chromosome from the female parent and both carry the same gene at the same locus but may contain different alleles of the gene because both chromosomes comes from different origin.
