When two chromosomes match up what is it called

Which of the following is an example of a non-falsifiable hypothesis? a. there is a teacup orbiting the milky way galaxy. b. there is no life on mars. c. the human species started in africa. d. humans cannot live without the amino acid methionine

Twind is considered to be an abiotic factor because it.?

Nucleic acid certain protein cell membranes certain carbohydrates