The length of the hockey stick is generally the easiest to determine, but imperative for a playerâs success in the game. Sticks usually come in four sizes: senior, intermediate, junior and youth. Each size normally reflects a smaller shaft circumference and a softer flex.
Factors in the environment may influence the rate of mutation but are not generally thought to influence the direction of mutation. For example, exposure to harmful chemicals may increase the mutation rate, but will not cause more mutations that make the organism resistant to those chemicals.In this respect, mutations are random  whether a particular mutation happens or not is unrelated to how useful that mutation would be.actors in the environment may influence the rate of mutation but are not generally thought to influence the direction of mutation. For example, exposure to harmful chemicals may increase the mutation rate, but will not cause more mutations that make the organism resistant to those chemicals.
A mutation rate is the number of mutations which occur on average per generation. Mutation rates are determined by comparing the DNA of offspring to parents, and counting up the differences. Mutation rates differ from species to species and can be affected by the environment (more UV radiation for example can produce higher mutation rates), and by the age of the parents. When a child is born they receive half a copy of their DNA from their father and half a copy from their mother.