Tutor profile: Isaiah H.

What type of variable is the factor that is held constant to test the impact of the independent variable?

The answer is the control variable. The control variable is necessary in any type of scientific experimentation and is used as a baseline to measure the true effectiveness of the experimental results. From a sociological perspective, it is important to determine what is "normal" before deep diving into why you perceive something as abnormal. For example, if you are testing the effects of LSD on 10 participants and how it causes violent behaviors, it will be important to also test 10 or more participants who don't take the drug in order to measure their level of violence as well. If you determine that the control participants are equally violent, then it can be concluded that the drug doesn't make people violent. If the participants on LSD are much more violent than the control participants, it can be concluded that LSD makes its users lash out in violent behavior

Describe how it is possible for bears to hibernate during the winter months. During this time, they do not eat, drink or exercise. Though they are inactive for months at a time, they do not experience any muscle loss, and they are not at risk for any complications.

Relatively recent studies have shown that brown adipose tissue in bears possesses catalase activity which enhances the ability for the tissue to synthesize glycogen. The tissue stores medium lipid chains that are consumed during hibernation and the smaller lipid chains are shown to allow an efficient path of energy production during hibernation. This energy path is more efficient than glycolysis during this time. Excess energy is released as a heat waste product that keeps the hibernating animal warm during the cooler months.

A female cow is heterozygous, and a male cow is homozygous recessive. The gene for fur color has 2 alleles. The dominant allele is 'F' for the brown cows, and the recessive allele is 'f' for the white cows. What is the ratio of possible phenotypes and genotypes of their offspring

In order to attack this problem, we will have to use a punnett square. The punnett square helps for us to determine the possible phenotypes (physical characteristics) and the possible genotypes (genetic characteristics). When the question says that the female cow is heterozygous, we know that heterozygous means that the female possesses 2 different genes. One gene here will be dominant (represented with uppercase), and the other will be recessive (represented with lowercase). We also know that the female will have 2 X chromosomes. The male here is homozygous recessive. Homozygous meaning that it has 2 of the same genes, and recessive meaning that those genes will be represented with a lowercase. We also know that the male will have an X and a Y chromosome. When we make the punnett square, I like to put the female (XX) characteristics on top, and the male (XY) characteristics on the side F(x) f(x) f(x) Ff(xx) ff(xx) f(y) Ff(xy) ff(xy) When we do the crossings on the punnett square, we see that there is a phenotypic ratio of 1:1. This means that there is a 50% chance of having a brown cow (contains an uppercase F) and a 50% chance of having a white cow (contains only lowercase 'f'). The genotypic ratio is also 1:1 because there are only 2 possibilities (Ff or ff).