To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
The correct answer is random fertilization.
Together with crossing over and independent assortment, random fertilization represents the way by which sexually reproduction contributes to genetic variation. <span>Random fertilization refers to the random event of fertilization when there is no way in knowing which sperm will fertilise which egg (64 trillion possible combinations of genes that can occur during fertilization). Any sperm cell from the male can fuse with any egg cell from the female.</span>
The answer would be Sprots Medicine
Answer:
I believe that it is the lettuce.
Explanation:
it is the fist thing in the graph so it is the start/producer of the chain.
The researchers will use mice instead of opossums or humans to determine whether the cells of the ear bones originated from the same embryonic cells as the cells that form the jaw in other vertebrates because in this type of experiment, organisms that are ideal are the ones that have a short life span, easy to be researched on and easy to mantain.
It will be very tedious and demanding to use opossums and humans in this type of practical experiment because,it is against the culture and norms guilding human living and existence to use humans as model organisms,opossums as well are very bad model organisms because unlike the mice,opossums are long lived and it will be very difficult to raise and maintain an opossum in a laboratory.
Humans and mice are both mammals just that human is a higher mammal but they share similar features in terms of pattern of development,though there is a clear difference during their early development,so because of the common ancestry shared by the mice and humans,the result of the experiment on the mice with share a close similarity with the pattern that is expected in humans.
