Researchers studied mice embryos 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. Why would the researchers use mice instead of opossums or humans? Do the results from mice tell you something about your own ears? Why or why not?

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.

the supermassive black hole is in the middle of the galaxy.

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.