What is the difference between homologous chromosomes and sister chromatids?
imma use symbols. I used to have the same confusion. let this stroke ” I ” represent a chromosome. A pair of sister chromatids is actually ONE chromosome. It’s just that the single chromosome ” I ” has replicated around it’s centromere (the central part of the chromosome). Hence a sister chromatid can be represented by ” X ” Homologous chromosomes are a pair of identical chromosomes. You know that we humans have 46 chromosomes? 2n = 46? That means humans have one set of genes, half of it is paternal, the other half is maternal. During the creation of gametes, similar chromosomes PAIR up. The similar chromosomes are called HOMOLOGOUS. Similar meaning they have the same length and the alleles controlling certain traits and on the same places on the chromosome. (If this part is not required in your syllabus, don’t pay attention to it). So if you have chromosome ” I ” then during meiosis, it will pair up with another chromosome ” I ” which it is similar to.