(Question)
Q: Blood calcium levels are tightly regulated by the what system? Choices: - digestive - cardiovascular - nervous - endocrine A:
(Answer)
endocrine

(Question)
Q: Double strands of what wrap around histone proteins to form nucleosomes, which are coiled into a chromatin fiber? Choices: - bacteria - ribosomes - chromatids - dna A:
(Answer)
dna

(Question)
Q: What cause the rippled surface of the ocean? Choices: - winds - tides - earthquakes - waves A:
(Answer)
waves