Answer:
(3) a single variable
Explanation:
A control experiment can be defined as an experiment in which a condition assumed to be a probable cause of the effect is being compared to the same situation by the scientist without involving or using the suspected condition.
Controlled variable refers to anything or quantity such as group, person, event, etc., that is held constant by the researcher during an experiment and as such is limited.
The first trial of a controlled experiment allows a scientist to isolate and test a single variable.
Generally, most scientific experiments usually have a control group so as to avail scientists (experimentalists) an ability to compare the outcome of their test results before testing a single variable. This control group is not given the treatment or influenced by the same single (independent) variable as the experimental group.
Therefore, this is the reason why science completely or totally rejects any hypothesis which is not supported by observations, as well as the results obtained from control experiments.
This ultimately implies that, for any hypothesis to be acceptable in science, it must be supported by observations and the results of control experiments; this give rise to factual informations, theories and by extension solutions to problems.
Answer:
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Explanation:
the autotrophs in the given series are sunflower and algae
Lava that hardens on the surface is called an extrusion. The rock layers below an extrusion are always older than the extrusion. ... There, the magma cools and hardens into a mass of igneous rock called an intrusion. An intrusion is always younger than the rock layers around and beneath it.
White blood cells also called leukocytes are the cells that help fight infection causing protection of the body against a disease or foreign substance. An example is a leukemia which then creates a large number of abnormal white blood cells.
Answer:
Scientists figured out that the outer core must be liquid because S waves do not pass through it, but P waves do. The behavior of P and S waves also indicates that the inner core is solid. The speed of seismic waves also depends on the density of the material through which they are traveling.
Explanation:
