Do you mean when nucleotides get damaged or when they match to each other incoreectly? (which cuases mutants) Specialized Enzymes repair, different one respond to help different types of damage. Detail the question more, maybe then i can help more.
Answer:
C
Explanation:
(Humans) body cells and viruses both contain RNA and DNA. So both have this similarity.
Answer:
a.There are three signaling pathway
1- Reception in which molecule binds to receptor
2- Signal transduction in which activation of intracellular pathway and enzyme occur.
3- Cellular response in which specific response of cell occur according to receptor and ligand.
b. Three types of receptors are
1- autocrine
2- paracrine
3- endocrine.
Explanation:
autocrine receptors are signaling pathway in which cell releases its molecule and bind to its own cell receptor example cancer cells while paracrine in which ligand binds to other nearby cell receptor and it is used during development and in endocrine cell target distinct cell and travel through blood stream like hormones functioning.