<span>Norepinephrine uses the Second
Messenger System, which means, cells signal to each other what molecules have
been released that will trigger a physiological reaction. </span>
<span>
This phenomenon is activated after the ligand (ion or molecule) is bonded to its receptor
(protein molecule), creating a variation that causes a chain-reaction, that will
finally activate the Second Messenger. The latter will activate intercellular
molecules that will be able to control the cell’s activity. </span>
B) bacteria, are producers
you could find the answers if u look up the name of it like
4.3 powering the cell: cellu.... answer
Answer:
The correct answer is -
A. a, c, g
B. e, b, f & d
Explanation:
Part A- the options a, c, g are the options that show mutation or replacement by a single base change
a) Phenylalanine: UUU UUC
Leucine: UUA UUG
Only one base change
c) Alanine: GCU GCC GCC GCG
Thr: ACU ACC ACA ACG
only one base change
g) Prolin: CCU CCC CCA CCG
Serine: UCU UCC UCA UCG
Part B:
All other replacements will not be consistent with the Genetic Code if single base substitutions occur in option e, b, f & d
Answer: The DNA double helix is held together by two types of bonds,
covalent and hydrogen.
Explanation: Covalent bonds occur within each linear strand and strongly
bonds the bases, sugar and phosphate groups.