Question

The genome of Daphnia pulex, a small freshwater crustacean, includes approximately 30,000 genes in ∼200,000 kb of DNA. How does the genome compare to that of Drosophila melanogaster, another arthropod, and to that of human?

Short answer

Daphnia pulex , a small fresh water crustacean has a genome of size 200,000 kb whereas Drosophila melanogaster, a fruit fly belonging to Arthropoda has a genome size of 180,000kb.

Step-by-step solution

Size of DNA and intergenic distance.

There is a great variability in the size of genome of different organisms . DNA size is measured as kb

( kilobytes). More the number of genes in a genome , more is the size.

Explanation.

While Daphnia has 3000 genes in its genome thereby the size is approximately 200,000 kb, On the other hand, Drosophila melanogaster has 13,000 genes . Comparing this to the human genome with 23000 genes has approximate size of 3,038,000kb . So the size of human genome is quite large as compared to Daphnia and Drosophila since the number of genes are also more.