There are 4 chromosome pairs in Drosophila melanogaster. One pair of gonosomes and three pairs of autosomes.
in a homologous chromosome there are two chromosomes ( a chromosome and a sister chromosome)
A normal human has 23 pairs of chromosomes, i.e. 64 chromosomes. People with Downes Syndrome have an extra copy of the 21st chromosome so they have 65 chromosomes.
46 in humans, which is the same as 23 pairs
23 pairs or 46 chromosomes in a human body.
46.