Rabbits were introduced to Numa Island in the nineteenth century. Overgrazing by the enormous population of rabbits now menaces the island’s agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a chance that the virus will infect the bilby, an endangered native marsupial. The government’s plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife. Which of the following, if true, most seriously weakens the argument?A. There is less chance that the virus will infect domestic animals on Numa than that it will infect bilbies. B. There are no species of animals on the island that prey on the rabbits. C. Overgrazing by rabbits endangers many of the plants on which bilbies feed. D. The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits. E. There is no alternative means of reducing the rabbit population that would involve no threat to the bilby.

C. Overgrazing by rabbits endangers many of the plants on which bilbies feed

Explanation:

                                          will increase the threat to native wildlife.

Overgrazing by rabbits endangers many of the plants on which bilbies feed

The government could use this argument to introduce the virus. The statement is saying that the rabbits are competing with the endangered bilby species for food. Bilby is already being affected by the rabbit´s presence, and their survival is at serious risk because the rabbit is the strongest competitor.

Considering that rabbit is an invasive and competing species, the bilby is already affected. Their probabilities of survival are minimal. So, even in the absence of the virus, native wildlife is already being threatened.

If the virus is introduced to reduce the rabbit population, it might affect bilby as well, but the island´s agriculture will not be as affected as it is now.

identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.v

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.