When we hear the word bacteria, the first thing that comes to mind is infection of some kind. But bacteria are also beneficial to man. Can you choose the statements that correctly describe the beneficial roles bacteria play in our lives?
Decompose organic wastes into humus which can improve soil fertility.
Bacteria in human colon synthesize vitamins B and K.
Used in the pasteurization of the milk we drink.
Used in the preparation of some dairy products like yogurt and buttermilk.
Fixes atmospheric nitrogen so it can be used by other organisms.
Used as a form of cattle feed on large farms when village runs low.

There is a liquid capsule inside a cup full of liquid. the cup full of liquid has salt in it and the liquid capsule has no salt in it. in which direction will the solvent flow? a. the salt does not have to move b. from the capsule to the larger cup c. equally between the capsule and the cup d. from the larger cup to the capsule

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.

The smallest parts of these that retain their original properties are called