George, who is 60, couldn't understand why he was slowly gaining weight. he was eating the same amount of food that he had each day since he was 20 and he exercised regularly. what could explain his weight gain?

a) his metabolism had slowed down.
b) he is likely very ill; this situation is very unusual.
c) he really wasn't gaining weight; his height was decreasing.
d) he always overate after exercising.

Substances effect: partially blocks (h+)/pyruvate symporter, interfering with the transport of pyruvate into the mitochondria. will this make the body lose or gain weight?

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

Asolution of an enzyme and a substrate was placed in a water bath and the temperature of the reaction was raised gradually. the graph shown was plotted at the end of the experiment. what can be concluded from the graph? a) temperature has no effect on the activity of the enzyme. b) the effect of temperature on the enzyme is unpredictable. c) the enzyme shows increased activity up to a certain temperature. d) the activity of the enzyme is inversely proportional to the temperature.