This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web.
a. bacteria and fungi, the decomposers, recycle carbon from dead organisms.
b. carbon is found in the grass and is passed from one level to the next in this food web.
c. all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere.
d. plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.

Match the types of competition to their descriptions

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

Mineral rich water heated by newly found oceanic crust escapes through cracks in the ocean floor called