What is the term for changes in the internal or external environment that cause a response? A. stimuli
B. signals
C. messages
D. nerves

Will give brainlest for quick and correct answer

A

Explanation:

It is a detectable change in the physical or chemical structure of an organism's internal or external environment. Although stimuli commonly cause the body to respond, it is the CNS that finally determines whether a signal causes a reaction or not.

the reason the two sea urchins don't compete with each other for food, resources, etc. is because the urchins have adapted to the environment but they have also adapted to each other. this is most likely because the genes of the sea urchins.

brain development. a child's brain undergoes an amazing period of development from birth to three—producing more than a million neural connections each second. the development of the brain is influenced by many factors, including a child's relationships, experiences and environment.

explanation: