Answer:
A reaction that joins the nuclei of two atoms into one
Explanation:
Think of the words "nuclear fusion".
Nuclear = "relating to a nucleus"
Fusion = "joining"
So, nuclear fusion is the joining of two nuclei into one.
A and B are wrong, because chemical reactions involve electrons.
D is wrong, because the splitting of a nucleus is fission.
Chloroplast , cell walls and centriols can be found in plant cell but not in animal cells.
Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.
Lipids are not polymers because they contain one molecule and are not macromolecules.
When our red-sensitive nerves in our eyes cannot respond to light properly this will result in color blindness - b.
When either of the three light-sensitive nerves in our nerve tracts; either green, red or blue, we become to color blind for a certain spectrum of light from nature.
