Properly identifying each species.
Accurately recording his findings.
Not interfering with ecosystem while studying the birds.
Can you put the terms as well, please
<span>When cells were first taken from Henrietta Lacks, she was suffering from cervix cancer. Henrietta Lacks was a woman whose cervix cancer cells were used as the source of the HeLa cell line nowadays used in medical research. During treatment for cervical cancer in 1951, the cells were taken without her knowledge. The cells were cultured by George Otto Gey who created the HeLa cell line.</span>
D. He controlled variables by studying one or two traits at a time
