Answer: Chlorine
Explanation:
An independent variable can be define as changable variable, which can be used to determine it's impact over the other variable(s) in the experiment. Dependent variable cannot be changed manually instead changes occur in the independent variable is because of impact of independent variable.
In this experiment, chlorine is the independent variable. The effect of which can be observed on the hair color, which is a dependent variable.
Answer:
Different brands of nail polishes used by Sarah.
Explanation:
While conducting an experiment two different variables are considered namely dependant variable and independent variable. The variable which is continuously changed to see the effects is called as independent variable and the variable which is being tested is called as dependant variable.
In the given scenario, Sarah want to know best brand of nail polishes which lasts longest without chipping. Thus the different brands of nail polish used by her is considered as independent variable.
Ans.
Sickle-cell disorder shows defected red blood cells, due to mutation in gene that code for hemoglobin. The mutated genes for sickle-cell disease are found in higher percentage of sub-Saharan African population as it provides protection against malaria as compared to population of United States.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Thus, the evolutionary process behind this is 'natural selection.'
The possible combinations are as follows
R r
R RR Rr
r Rr rr
so you would have a ratio of 1RR : 2Rr : 1rr
