Match the following mechanisms (Column I) with their correct example (Column II).

Column I	Column II
A. Heat-generating and heat-retaining mechanisms	i. increased metabolic rate (thyroid hormones, sympathetic nervous system)
B. Heat-dissipating mechanisms	ii. vasodilation of blood vessels of the skin (decreased sympathetic tone)
	iii. increased activity of sympathetic cholinergic fibers to sweat glands.
	iv. shivering
	v. vasoconstriction of blood vessels of the skin (increased sympathetic tone)

#Question id: 59

#Unit 1. Molecules and their Interaction Relevant to Biology

Nitrogen (N) normally forms three covalent bonds with a valence of five. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). What do you predict to be the charge on ammonium?

#Question id: 64

#Unit 1. Molecules and their Interaction Relevant to Biology

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol ________.

#Question id: 64

#Unit 1. Molecules and their Interaction Relevant to Biology

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol ________.

#Question id: 66

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements regarding isomerism is incorrect regarding biomolecules?

#Question id: 67

#Unit 1. Molecules and their Interaction Relevant to Biology

When a region of DNA must be repaired by removing and replacing some of the nucleotides, what ensures that the new nucleotides are in the correct sequence?

#Question id: 69

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is the diastereomer of the following compound?