Answer:
Hormones act as first messenger but not as second messengers.
Explanation:
Second messenger act as signaling molecule which are secreted in response to various biological signals generated by first messenger such as hormones,neurotransmitters etc.Second messengers include various bioactive molecules such as cyclic AMP(cAMP),cyclic GMP(cGMP),inositol triphosphate(IP3),diacylglycerol(DAG),calcium ions(Ca2+) etc.
Hormones are extracellular signaling molecules whereas second messengers are intracellular signaling molecules.
Answer:
Duplication is a type of mutation that involves the production of one or more copies of a gene or region of a chromosome. Gene and chromosome duplications occur in all organisms, though they are especially prominent among plants. Gene duplication is an important mechanism by which evolution occurs.
Answer:True
Explanation:Basically thymine diamers are mismatched pairs (thymine binds with another thymine instead of binding with adenine) and may lead to unwanted results so the mismatching can be repaired by using two methods which are as follows :
1-the PRE enzyme activated by blue light breaks the thymine diamer and some of the surrounding bonds the strand is cut and DNA polymerase then restores the normal base pairing
2-UVR system breaks dimer creating a gap when a gap is created and the molecules appear unpaired it is filled by proof readers hence restoring normal base pairing.
What I know is that amino acid has side chain, amine groupe ,and groupe of carboxyl so what make them difference is side group where the is 20 different R-group which give each individual characteristics