A biologist is conducting an experiment to determine how light affects the reproduction of Bacteria X. The biologist is trying to decide the best way to conduct his experiment in order to collect meaningful data.

Which of the following experiments would help him collect the best data?

The best way by which the biologist can conduct his experiment -in order to collect meaningful data- is place a Petri dish with Bacteria X in a lighted area and a Petri dish with the Bacteria X in a darkened area, and then observe the rate of reproduction over time.

Explanation:

Options for this question are:

A.  Place a Petri dish with Bacteria X in a lighted area and a Petri dish with the Bacteria X in a darkened area, and then observe the rate of reproduction over time.

B.  Place a Petri dish with Bacteria X in a lighted area and a Petri dish with Bacteria Y in a darkened area, and then observe the rate of reproduction over time.

C.  Place a Petri dish with Bacteria X in a sunny window and an identical Petri dish under a grow lamp.

D.  Place a Petri dish with Bacteria X in a moist, dark area and record the rate of reproduction over time.

The aim of the biologist is clearly to see how light influences the reproduction of bacteria X. In this case, the design of the experiment is simple, as he must separate his sample into two groups, exposing each group to controlled conditions, light and dark.

The stimulus, presence or absence of light, is the independent variable, while the rate of reproduction is its dependent variable.

If the biologist observes that bacteria X reproduce better in the illuminated area, it means that light is a factor that promotes reproduction in that bacteria, or that darkness negatively affects reproduction.

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Example of an experiment with bacteria link

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."