Q: In the freshwater flatworms, protonephridia serve chiefly in what? Choices: - enculturation - excretion - thermoregulation - osmoregulation A:
osmoregulation

(Question)
Q: Unlike wild animals, what type of species are genetically uniform, making them more vulnerable to die-out from disease? Choices: - free-range species - urbane species - mammals - domestic species A:
(Answer)
domestic species

Ques: Q: A system of glands secretes what chemical messenger molecules into the blood? Choices: - metabolytes - enzymes - acids - hormones A:
Ans: hormones

(Q).
Q: Unlike nuclear fission, which involves dangerous radioisotopes, nuclear fusion involves what two harmless elements? Choices: - magnesium and helium - hydrogen and oxygen - hydrogen and carbon - hydrogen and helium A:
(A).
hydrogen and helium

Ques:Q: What type of fibers are made mostly of protein in living things? Choices: - organ fibers - liver fibers - connective tissue fibers - muscle fibers A:

Ans:muscle fibers

Ques: Q: How many major forces of elevation cause allele frequencies to change? Choices: - one - five - three - four A:
Ans:
four