In a food chain and web, only 10% of the energy produced by a level in a food chain is passed on to its predator so there has to be many more “prey” than “predators”. If 2000 kcal of energy are available in grass, how much energy would be available to the cow that eats the grass? How about to the human that eats the cow?

If only 10% of energy is passed down the cow would only get 200 kcal of energy from the grass. The human would get 10% less than that which is only 20 kcal of energy from the cow.

Explanation:

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.