Genetic characteristics that we can't control include
a.
height and amount of muscle fibers
b.
amount of muscle fibers and heart rate
c.
heart rate and flexibility
d.
flexibility and amount of daily exercise

Option A

Explanation:

Height and amount of muscle fiber are the genetic characters that cannot be controlled by external means. These are genetic factors which is controlled by the genes that is carried from the parents to the child.

The height of the child is dependent on genetic factor and cannot be controlled by external factors like medication or any other chemicals or medical procedures.

The amount of muscle fiber is also controlled by genetics and is also dependent on the parental body type which is not controlled by the external factors.

a plastic spoon that has a temperature of 78° f is placed into a bowl of soup that has a temperature of 84° f. which of these correctly describes what will happen?

energy as heat moves from the soup to the spoon.