What are Homologous chromosomes?
Sister chromatids
- The two chromatids which have the same DNA base-pair sequences are called Sister chromatids.
- The chromosome made up of two sister chromatids, which are duplicates of each other, is called Homologous chromosomes. In this chromosome, sister chromatids have the same relative position and
Homologous chromosomes
- Segments of DNA are called Genes. Each gene is located at a particular part of the DNA which forms the locus of that particular
- Every chromosome has several such loci of specific
- The sister chromatids are formed after DNA replication and thus have the same loci for all the genes. Their centromeres are also at the same
- When they duplicate, they join together with each other. Both the chromosomes are identical so they are called Homologous chromosomes.
Genes and Locus
Loci of Genes
How many chromosomes do humans have?
              Chromosomes
- In all human body cells or somatic cells, there are 23 pairs of
- 1 pair is of sex chromosomes while 22 pairs are
- Autosomes are pairs of homologous chromosomes so they are also called Diploid with two complete sets of chromosomes.
- The sex cells do not have two sets of complete chromosomes. Thus, they are called
Haploid.
Homologous chromosomes
Human Chromosomes
Diploid cell and Haploid cell
- Diploid chromosomes are referred to as 2n while haploid chromosomes are referred to as n.
- In sexual reproduction, both the parents contribute equally to the chromosomal
- After fertilization, the chromosome set of 23 chromosomes from each parent cell will combine to form a 46 chromosomal
