Choice B:
More photosynthesis leads to more oxygen in the atmosphere and oceans.
Answer:
8. D
9. A
10. A
11. C
12. D
Explanation:
8. Natural selection works on variation that exists in the genes of organisms. Antelopes who have genetic variation that makes their legs more muscular are at an advantage because they can outrun predators. This increases the chance that they will reach reproductive age, and be able to pass this advantageous trait onto their offspring. Over time, this selection pressure makes the variant more common in a population.
9. Beneficial traits are those that give a selective advantage. This could be one that helps it outrun predators (like above), avoid illness and death, gives it a reproductive advantage (i.e. more attractive to mates), or makes it better able to digest certain foods, for example. The formation of cancer cells would be harmful for an organism, reducing its fitness and perhaps leading to death. The inability to reproduce would mean genetic info is not passed on to the next generation, and stopping the production of an essential protein would likely lead to death. However, resistance to a virus would help an organism avoid illness and death, improving fitness.
10. Genotypes are what organisms inherit from their parents, i.e. the genetic information that is passed on. However, the way in which different alleles interact and are expressed is the phenotype. If we take the above example, natural selection is acting on the phenotype of muscular legs. If an antelope had the muscular leg genotype but for some reason it was not being expressed (maybe another gene is interfering with it), then the antelope would not have a selective advantage, and natural selection could not be act on the trait.
11. A trait that better suits an organism to its environment will be selected for by natural selection. This is because that organism is more likely to survive due to the trait, giving it a selective advantage. Therefore, if a mutation arose making the giraffe more adapted to the environment, it would be positively selected for, and through evolution would become more common.
12. This is an example of selective breeding, which has been happening for generations. Farmers spot desirable traits, and cross horses with these traits in an attempt to enhance the trait or to ensure it is passed on to the next generation. This is not natural selection, because farmers are making it happen artificially. It is not cloning or recombinant DNA, which are terms scientists use for actually manipulating the DNA in the lab.
Answer:
This question lacks options, options are:
A) ADH
B) aldosterone
C) atrial natriuretic hormone
D) oxytocin
E) prolactin
The correct answer is B.
Women have a tendency to retain water during part of the menstrual cycle because estrogen mimics the action of <u>aldosterone</u>.
Explanation:
The female sex hormones produced by the ovary (estrogens and progesterone) are substances that, through the blood, will carry messages to all the organs of the female genital system (uterus, tubes and ovaries) to achieve their correct function. Aldosterone concentration normally increases at the time of ovulation and remains elevated during the luteal phase of the menstrual cycle. Women present during the premenstrual phase, compared to the luteal and follicular phases, an increase in body weight, due to an increase in fluid retention, this because the menstrual cycle modulates the renin-angiotensin-aldosterone system. High levels of estrogen and progesterone in the mid-luteal phase are associated with a greater increase in adrenal and renal hormones and retention of more volume.
Answer:
h - height
Explanation:
gravitational potential energy = m * g * h
m stands for mass. Mass doesn't change in physics
g stands for gravitational acceleration. It is a constant.
h stands for height. When the skater moves up and down the track the height from the ground changes. Therefore this variable does change.
The could walk across wet asphalt and get stuck, creating an imprint over time, or they could have more asphalt put on top of them
