The first molecule of life was likely ____
a. DNA
b. RNA
c. oxygen
d. carbon dioxide
e. proteins
ANSWER: b
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Margarine is made by hydrogenating vegetable oils so that they take on the consistency of butter. Propose a chemical basis for this change from a liquid to a solid
A. Hydrogenation of fats changes them from saturated to unsaturated, which are more solid. B. Trans-fatty acids are changed from unsaturated to saturated, allowing them to solidify. C. Trans fatty acids are changed from saturated to unsaturated, allowing them to solidify. D. Hydrogenation of fats changes them from unsaturated to saturated, which are more solid.
Why is it advantageous for organisms not to be consciously aware of all the activity in their nervous systems?
What will be an ideal response?
In a person with cystic fibrosis, the mutation
causes which of the following to happen?
a. the protein clings to the inner surface of the plasma membrane b. the protein never leaves the endoplasmic reticulum c. the protein is shuttled to the nuclear membrane instead of the plasma membrane d. the protein is shuttled to the plasma membrane instead of the nuclear membrane e. the protein is expelled from the cell by exocytosis before it can do its job
Impulses conducted along the transverse tubules of the muscle fiber stimulate
A. the release of ATP. B. tropomyosin and troponin binding. C. the release of calcium ions. D. the release of acetylcholine. E. the binding of actin to the Z lines.