In diffusion, movement of particles across a membrane is driven by differences in
a. size.
b. shape.
c. concentration.
d. force.

In familial hypercholesterolemia individuals homozygous for the allele causing the disorder completely lack receptors on liver cells that take up cholesterol from the blood stream. heterozygous have one-half the number of receptors while individuals homozygous for the normal allele are phenotypically normal. this is an example of a.epistasis b.complete dominance c. incomplete dominance d. codominance

Which best explains why there are 64 possible codons in the genetic code and only 20 amino acids that make protiens of living organisms on earth

Directions: read the descriptions of the four islands presented in the lesson. 1. list two new traits that each new species of rat might demonstrate as it adapts to the conditions on each island. 2. introduce one of the four new rat species to another island and describe one challenge it would encounter and one success as it adapts to its new environment.