Using the scenario, identify each of the parts listed below: Mr. Lehman wanted to know whether or not his students would do better on a quiz if he promised them candy. He guessed that the more candy that his students were promised, the better they would do on the quiz. He had all of his classes participate in the experiment. There were two groups in all. The first group was not promised any candy if they did well on the quiz. The second group was promised a candy bar if they did well on the quiz. Group #1 got an average of 70% on the quiz. Group #2 got an average of 90% on the quiz. Mr. Lehman then decided that if students were promised a candy bar, the better they did on quizzes. He then repeated the experiment with different students.

a) Hypothesis:
b) Dependent Variable:
c) Independent Variable:
d) Experimental Group:
e) Control Group:
f) Conclusion:

haploid cells;

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.