13. a basic observation of a star is how bright it appears. this brightness is known as the star's a. absent magnitude. b. apparent magnitude. c. absolute magnitude. d. luminosity.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

List two new traits (structural or behavioral) that each new species of rat might demonstrate as it adapts to the conditions on two of the four islands. choose only two islands that are described in the lesson. record the island latter and the major habitat feature of the island. then list two new traits each rat subspecies might demonstrate in order to survive the habitat on that island. note: new traits should be unique to that island and be in response to that island’s habitat feature. i cannot remember islands that were names in the lesson so only answer if you have done the lesson (5.13 life science 7b) choose 2 of the islands and describe a structural and a behavioral trait for a rat on each island so 4 total answers, 2 different structurals and 2 different behaviorals, one for each rat for each island

Select the correct answer. a chestnut-colored horse mates with a white-colored horse to produce a brown and white spotted offspring. what is the type of inheritance pattern?