From the organ systems listed below, select the correct sequence of organs found in each system.
cardiovascular, digestive, endocrine, urinary, integumentary
heart, stomach, lungs, kidneys, hair
heart, liver, pituitary gland, kidneys, skin
blood vessels, pancreas, kidneys, lungs, n

An easy way to calculate the amount of energy available at each level is to what?

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

The term equestrian relates to which animal? bulls cows horses pigs