Which organism did Gregor Mendel use to discover the basic principles of genetics?

A) Drosophila melanogaster (fruit fly)

B) Escherichia coli (bacterium)

C) Mus musculus (mouse)

D) Pisum sativum (pea plant)

E) Caenorhabditis elegans (nematode worm)

D) Pisum sativum (pea plant).

Explanation:

Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.