The changing quantities in an experiment are called variables. A variable refers to any trait, factor, or a condition, which can prevail in distinct amounts or kinds. An experiment generally exhibits three kinds of variables: independent, dependent, and controlled.
The independent variable refers to the one, which is modified. On the other hand, the dependent variable is implied to observe that how it reacts with the change made to the independent variable. The controlled variables refer to the quantities, which one wants to remain constant.
In the given case, that is, heating a cup of water to witness that whether the sugar will get more easily dissolve. In this, the independent variable refers to the temperature of the water determined in degrees Centigrade. The dependent variable refers to the amount of sugar, which dissolves completely measured in grams.
In this, the controlled variables are stirring and type of sugar. As more stirring might elevate the amount of sugar that dissolves, and different kind of sugars might dissolve in distinct concentrations. So, in order to make sure a fair test, there is a need to keep these variables similar for each cup of water.
A) A textbook definition would be that genetic drift is: a random change in allele frequency caused by a series of chance occurences that cause an allele to become more or less common in a population. In layman's terms, this means that genetic drift happens when luck makes the genetic pool of the population to deviate from what is expected.
B) The cause for this genetic drift is the aformentioned couple. Because amish communities are small and they select partners from their community, having even a couple of carriers of alleles in a community can make the allele freuency much larger than expected; for example, if the community was 100 persons, the percentage would be in the order of 1%, still much larger than the general population. Thus, the cause here is that a small population had a couple of carriers.
C) Sexual reproduction leads to a mixing of alleles from both mother and father and helps diversity. When a population is isolated, the gene pool is fixed and no new genes can come in, reducing diversity. Also some people that have an allele might die, hitting diversity even more. Finally, having a small population creates a strong pressure in some circumstances that leads to elimination of some traits and diversity.
Some of the aspects that help you determine whether a study is rigorous are questions and hypotheses that can be answered, adequated method use, and bibliography.
Rigorous is a term that refers to a quality that focuses on accuracy and precision to comply with norms, precepts, and pre-established rules. This term is widely used in science to refer to the precision of a study or investigation.
Therefore, when it is established that a study is rigorous, its attributes must be taken into account, such as:
- Questions and hypotheses that can be answered: This aspect refers to the investigator having the ability to limit his study so that it is appropriate to do so and does not include too much information that makes his study "impossible".
- Adequated methods use: This refers to using the appropriate methods to reach feasible conclusions, for example, methods of observation, deduction, induction, among others.
- Bibliography: This refers to the research or study being supported by reliable sources so that it is as accurate as the information it provides.
Learn more in: brainly.com/question/14617975
