Fossils show that this animal lived in the dark ocean. Each animal had a disc or a holdfast to attach it to the deep ocean floor.

Lactic acid and ethanol fermentation differ in that:

A. FADH2 is oxidized to FADH in lactic acid fermentation, but NADH is oxidized to NAD+ in ethanol fermentation. B. NADH is oxidized to NAD+ in lactic acid fermentation, but FADH2 is oxidized to FADH in ethanol fermentation. C. lactic acid fermentation produces ATP by substrate level phosphorylation, but ethanol fermentation does not. D. ethanol fermentation produces ATP by substrate level phosphorylation, but lactic acid fermentation does not. E. ethanol fermentation produces CO2, but lactic acid fermentation does not.

The most likely explanation for the phenomenon where a protein may be found in different sub-cellular locations in different cells is

A. stabilization of the mRNA transcript B. alternative splicing C. RNA interference D. transport of mRNA from the nucleus to the cytoplasm

The receptors that detect the amount of salt in an

animal’s blood are a. mechanoreceptors. b. pain receptors. c. thermoreceptors. d. osmoreceptors. e. all EXCEPT “osmoreceptors.”

Answer the following questions true (T) or false (F)

1. Interferons alpha and beta are effective against viruses. 2. The resident microbiota have no role in defense against pathogen invasion. 3. Sweat can cause damage to bacteria because it contains salt and lysozyme.