Question

For professor appreciation day, you buy your favorite Biology professor a lovely houseplant. Your professor takes the plant home, places it in a windowsill and waters it every other day, as she should. Before she goes on a vacation for 2 weeks, she asks her neighbor to take care of her plant while she is gone. The foolish neighbor remembers to water the plants but forget to ever open the blinds. When your professor returns, the plant is still alive but doesn’t weigh the same as when she left.

A) The plant will weigh the same when she returns from vacation because the plant has not been bringing in new carbon molecules during the vacation.

B) The plant will weigh more when the professor returns from vacation because the plant is not releasing any carbon molecules.

C) The plant will weigh less when she returns from vacation because the plant has been releasing more carbon molecules than it has been bringing in.

D) The plant will weigh less when she returns from vacation because the plant increased its rate of cell respiration during the vacation

Answer 1

C) The plant will weigh less when she returns from vacation because the plant has been releasing more carbon molecules than it has been bringing in.

The plant is not doing photosynthesis in the continued darkness but because it has to continue its life so it uses its respiration to oxidize the stored food it has. Thus the rate of respiration(catabolic) is way higher than the rate of photosynthesis(anabolic) hence the plant loses weight. It is the case that can be compared to the kind of starvation in us. Prolonged starvation makes us lean and lose weight because during starvation there is no consumption of food but only the expenditure of energy during respiration to continue our life and to extract energy from stored food inside our body.