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.
Chromosomes! They contain the recipe for making a living thing. They are found in almost every cell's nucleus and are made from strands of deoxyribonucleic adic (DNA)
D) The AV valves are supported by chordae tendineae so that they do not blow back up into the atria during ventricular contraction.
Organisms who happen to be best suited to an environment and reproduce most successfully will be consider successful in terms of natural selection.
Symptoms of severe anxiety evident in this case include; confusion, sweating, withdrawal, rapid speech, and a perceptual field that is reduced greatly and distorted. The perceptual field is heightened in mild anxiety while in moderate anxiety, the ability to think clearly is hampered but learning and problem solving can still take place. Additionally in panic, communication is unintelligible or there is an inability to speak.