Homologous pairs are two chromosomes, one from each parent, that are similar in shape and size and carry the same type of genetic information.
An allele is a variant form of a gene. Each person has two alleles for each gene - one inherited from each parent.
Chromosome: A chromosome is a long DNA molecule with part or all of the genetic material of an organism.
Gene: A gene is a segment on the DNA that contains instructions to make proteins – the key structural materials in our bodies.