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.
<span>All of the populations of different species that occupy and are adapted to a given area are referred as a community.
In a community, there will be many populations of different species. Population is a group of individual in a certain area. The more species in the community, the more complex it is.</span>
During a controlled experiment, a scientist will isolate and test (D) a single variable. A conclusion, nor a mass of information can be isolated or tested. A control group is the group that would receive a placebo, so testing that would be futile.
Answer:
More recent phylogenetic analyses, based on mitochondrial DNA, have suggested that the crocodile shark is closely related to either the megamouth shark or the sand sharks (Odontaspididae).
Answer:
Biodiversity hotspots are regions under surveillance of humans where threatened and endemic species of flora and fauna are grown. These regions have been identified as some of the world's most important ecosystems.
The two criteria for designation as a biodiversity hotspot are:
1. It must possess at least 1500 vascular plant species as endemics : It means the region must have a high percentage of plant species which are found no where else in the world.
2. It must have 30% or less native vegetation : It means that the plant species population is endangered and threatened to extinction.
