Answer:
Weight of the soil (500g)
Explanation:
According to this question, some students are conducting an experiment in order to find out which of the different soils used absorb heat the fastest. For the first test, they put 500 grams of SAND in a beaker and put a thermometer in the sand.
In an experiment, the variables that must be kept constant for all the groups is called the CONSTANT OR CONTROLLED VARIABLE. This is done in order not to influence the outcome of the experiment. In this case, the weight (500g) of the soil should be kept the same for all other tests.
This means that for the remaining soil being tested, 500g of each type of soil should be used.
The four factors that affect evolution are mutations, natural selection, genetic drift and the gene flow, In the case, if the ground finches that Grants studied, we can observe the working of the natural selection. Due to change in the conditions in the environment, the large beak was an advantageous trait that was favored by the natural selection. The result of this process was an increase in numbers of large beaked finches and decrease in small-beaked finches compared to the initial numbers in the population.
Answer:
<em><u>Individual organisms live together in an ecosystem and depend on one another. ... One category of interactions describes the different ways organisms obtain their food and energy. Some organisms can make their own food, and other organisms have to get their food by eating other organisms</u></em>
Answer: a tiny muscle connected to each hair follicle and the skin. When it contracts it causes the hair to stand erect, and a "goosebump" forms on the skin.
