ay whether each of the following situations is an example of altruism or reciprocity. a. Giving a few canned goods to the local food bank for its annual food drive: (Click to select) . b. Helping someone move her couch after she helped you study for an upcoming exam: (Click to select) . c. The biological relationship between cleaner fish and large predators in the ocean, in which cleaner fish keep the predator

Altruism

Reciprocity

Explanation:

Altruism is a biological concept used to describe the action of an organism which reduces its own fitness but increases the fitness of another organism. Reciprocity, on the other hand, refers to cooperation between two unrelated organisms in which the beneficial actions of one to the other is reciprocated either in the short or medium term.

Giving a few canned goods to the local food bank for its annual food drive is an action done to benefit those that patronize the food bank without any hope of it being reciprocated. Hence, it is considered altruism.

Helping someone move her couch after she helped you study for an upcoming exam and the biological relationship between cleaner fish and large predators in the ocean, in which cleaner fish keep the predator are both considered reciprocity.

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.