What was thomas hunt morgans main contribution to science

He discovered that certain traits were linked to the X chromosome.

Explanation:

Morgan's research led him to formulate the chromosomal theory of heredity and won him the Nobel Prize in Medicine in 1933.

At Columbia, Morgan began to study heredity with a team of students, experimenting with Drosophila ampelophila and Drosophila melanogaster, which proved Mendel's theories and enabled the principles of genetics to be determined. Morgan proved the reality of genes as bodily elements of specific location on chromosomes.

In addition, his major contribution to science was the discovery that certain characteristics were linked to the X chromosome, which made possible the formulation of the concept of inheritance linked to sex.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.