Answer:
The nervous system is stimulated from the environment, through sensory receptors. A stimulus is any form of energy that can be detected by the body. ... Animals normally only respond to stimuli which they select; they filter out certain stimuli that surround them, and react to others they choose to accept.
The Trout are probably not used to the water and their surroundings.
)Sexual reproduction maintains a constant level of variation in the population and requires less energy.
Answer:
Depending on changes, that occur with DNA, all types of DNA mutations can be divided into two main groups:
gene mutation;
chromosomal mutation.
Explanation:
