Answer;
D. controlled
An experiment in which only one variable is changed is a controlled experiment.
Explanation;
-A control experiment is an experiment where the researcher only changes one variable at a time in order to isolate the results.
In a controlled experiment, most conditions are constrained so that they do not change. One or two other conditions are then changed and measured by the experimenter. These are known as the independent variables.
For example; An experiment where all subjects involved in the experiment are treated exactly the same except for one deviation.
Freezing rain refers to the rain that falls through a shallow layer of cold temperature at zero degree Celsius or below zero degree Celsius near the earth surface. Celsius and Fahrenheit are two types of measurement that are used to measure temperature. The freezing temperature of water is zero degree Celsius. Zero degree Celsius is the same thing as 32 degree Fahrenheit.
Thus, the thermometer reading that is expected from a thermometer near the earth's surface during a period of freezing rain is 32 degree Fahrenheit.
The correct answer is pretest and posttest .
A pretest/posttest experiment is an experiment that includes double measurements at multiple points in time. In this kind of test, measurements (measurement of dependent variable) are taken both before and after a treatment.
Answer: Meiosis is a process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. Meiosis usually involves two distinct divisions, called meiosis I and meiosis II. By the end of meiosis II, the diploid cell becomes four haploid cells.
Explanation: