The key to the evolution of altruism is that a. recipients have to be more likely to carry the altruistic allele than nonrecipients. b. actors have to be more likely to carry the altruistic allele than nonactors. c. recipients have to be unrelated to the actors. d. nonrecipients have to be more likely to carry the altruistic allele than recipients.

The correct answer is b. actors have to be more likely to carry the altruistic allele than non actors.

Explanation:

Altruism is the behavior by an organism that benefits other organisms by costing its own fitness. The actor is the individual who is doing altruism and the recipient is the individual who is getting benefited by the actor's altruism.

An example of altruistic behavior can be seen in animal kingdom easily. Vampire bats give blood to those members of the community who were not able to go for search for blood show altruistic behavior.

Actors have altruistic genes that suggest them to behave altruistically. Non-actors may not contain alleles of altruism but the recipient might have altruistic alleles.

Hamilton's rule says that natural selection will favor the altruistic allele when rb > c.

where r = coefficient of relatedness between donor and recipient

          b = benefit received by recipient and

          c = cost paid by altruist.

Therefore, the correct answer is b.

thinking it would be d not too sure but i think it's right

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle