During the Calvin-Benson cycle (carbon-fixing reactions), in the red Columbine plant, high-energy electrons are transferred into a newly made 3-carbon compound. Eventually these electrons will end up as part of glucose molecules. What was the original source of these electrons in photosynthesis?
a. glucose
b. ATP
c. oxygen
d. water
e. carbon dioxide
D; Water is split during the light reactions liberating H+ ions, oxygen, and electrons. These electrons are accepted by chlorophyll, absorb light energy and are then sent through the electron transport chains and are accepted by electron carriers.
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The major histocompatability (MHC) molecule is important in a T cell's ability to _____
A) distinguish self from nonself B) recognize specific parasitic pathogens C) identify specific bacterial pathogens D) identify specific viruses E) recognize differences among types of cancer
Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D ? A + B, in the figure?
A) a B) b C) c D) d E) e
If you were to remove the anthers from a self-incompatible plant, how would this affect the fertilization of its female gametes?
A. Fertilization would continue, as selfincompatible plants rely on pollen from other individuals. B. Fertilization would stop, as selfincompatible plants are fertilized with pollen they produce. C. Fertilization would continue, as selfincompatible plants are fertilized with pollen they produce. D. Fertilization would stop, as selfincompatible plants rely on pollen from other individuals.
The trp and lac operons are both subject to forms of control that are typically called negative
Indicate whether the statement is true or false