The sedimentation coefficient:

is expressed in Svedberg units, named after the scientist who invented the ultracentrifuge.
is affected by the shape of the sedimenting particle.
is directly proportional to the molecular weight of a particle in an ultracentrifuge.
is obtained when a particle has neutral buoyant density.
values are additive, so a 50S ribosome will dissociate to two 25S subunits.

option D is incorrect

Explanation:

the sedimentation coefficient is measured in Svedberg units named after the scientist Theodore Svedberg. the shape of the particle being measured in the ultracentrifuge is one of the factors that determines the sedimentation coefficient. the values are usually not additive as the sedimentation coefficient is based on the rate at which a particle sediments in an ultracentrifuge and not on the size. for example, the sedimentation coefficient of eukaryotic ribosome is 80S but is made up of the 60S large subunit and the 40S small subunit.

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.  

answer///multiple alleles;