What causes the differences in physical characteristics like hair color among people?
different versions of genes
variations in DNA length
different numbers of chromosomes
variations in cell nucleus size

Identify the various levels of atmosphere. troposphere mesosphere exosphere stratosphere thermosphere

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.