(Question)
Q: How is population density expressed? Choices: - per arable land - number per household - arable land per capita - number per area A:
(Answer)
number per area

(Question)
Q: The entry of acidic chyme into the duodenum stimulates the release of what? Choices: - progesterone - gastrin - oxygen - secretin A:
(Answer)
secretin

(Question)
Q: What were the first photosynthetic organisms on earth? Choices: - mosses - trees - fungi - bacteria A:
(Answer)
bacteria