Answer:
A. donation of excited electrons by chlorophyll a to a primary electron acceptor
Explanation:
Photosystems are structures located at the thylakoid membrane that act to harvest energy light in order to convert it into chemical energy. Each photosystem is composed of a light-harvesting complex and a core complex, which in turn is composed of a reaction center. The photosynthetic reaction centers are multi-protein complexes that use light energy to catalyze the electron transfer across the chloroplast thylakoid membrane against a thermodynamic gradient. Moreover, antenna pigments are pigments that capture the energy from photons in order to transfer energy to other pigments in the photosystem (e.g., chlorophyll B and carotenes are antenna pigments, whereas chlorophyll A is the core pigment). Light energy absorbed by antenna pigments in the photosystems is transferred to the reaction center chlorophyll A molecules, thereby exiting electrons in the reaction center. A reaction center consists of two chlorophyll A molecules, which donate electrons to the primary electron acceptor.
Answer:
false
Explanation:
Although the majority of the air we breathe is N2, most of the nitrogen in the atmosphere is unavailable for use by organisms. This is because the strong triple bond between the N atoms in N2 molecules makes it relatively unreactive. However organisms need reactive nitrogen to be able to incorporate it into cells.
Answer:
A mutation in the DNA sequence of the gene for brown fur
Explanation:
The mutations are capable of changing the encoded protein product, in this case the gene that encodes for the fur color pigment. This mutation may have occurred during mitosis or meiosis divisions.
If it is a spontaneous mutation that occurred in the germinal line (meiosis) and confers an adaptive advantage, it will increase their frequency in the population.
Answer:
Sleet forms in winter storms, while hail is a warm-season type of precipitation. As noted above, sleet forms when snow melts in a warm layer and then refreezes into ice pellets as it falls though a cold layer. Hail, however, forms in spring, summer or fall thunderstorms.
Explanation:
I put this question before and got this one so I think it will be this answer. Hope this helps. :)
