1. the cell membrane is mainly made up of lipids and proteins. it acts as amazing
barrier to the surrounding environment. which of the following
statements about lipids best supports the argument that lipids
protect the contents of the cell?
a. lipids that are placed in water do not dissolve.
b. the tail of a lipid is made of carbon and hydrogen.
c. individual lipids in a membrane can rotate freely.
d. lipids are composed of a head and a thin tail.

we solve the problem using the hardy-wineberg equation.

let us start with the homozygous recessive proportion of individuals with sickle cell anaemia,

we have the proportion as q² = 0.25.

∴ q = 0.5 (frequency of hbs in population)

further,

solving for the frequency of normal cell by using the fact that,

p + q = 1

∴ p = 1 - 0.5 = 1 - 0.5 = 0.5

now we can calculate 2pq in p² + 2pq + q², which is the frequency for heterozygous carriers of sickle cell anaemia,

∴ 2pq = 2 x 0.5 x 0.5 = 0.5

and the homozygous normal cell individuals proportion is given by the expression,

∴ p² = 0.5² = 0.25

hence, the carriers for sickle cell anaemia are in proportion, 0.5, or 50%.