Substitution mutation is when a single base pair in a strand of DNA is replaced. This can cause an early stop amino acid, or the protein could change slightly, or the protein could be unchanged completely due to there being multiple base pairs to make an amino acid.
Answer:
The nitrogen cycle could not exist without first nitrogen. The cycle is about this specific element which goes to show that if this element is not present then, there will not be any nitrogen cycle. Also, an important factor for the cycle is the presence of the bacteria and other microorganism which are needed for the fixation.
Answer:
Crocodiles and snakes are more alike since they both develop from an egg.
Lizards and snakes are more alike since both species have a recent common ancestor.