Which of the following is a way in which elements and compounds are different? O A. Elements are pure substances, but compounds are not
B. Compounds can be broken down by physical changes, but elements cannot.
C.
Elements are made of identical atoms, whereas compounds are made of
identical molecules,
D. A compound contains many different kinds of elements, whereas an element
contains many different kinds of atoms.​

C.  Elements are made of identical atoms, whereas compounds are made of  identical molecules.

Explanation:

Elements are made of identical atoms, whereas compounds are made of  identical molecules because elements are made of atoms of only one kind while on the other hand, compounds are the pure substance that is made of molecules that is similar as well as different from one another. Both element and compound are pure substance. Compound can be broken down by chemical means whereas elements can not be broken down.

answers are:

lysogenic     viral dna merges with host cell dna

lysogenic     no symptoms

lytic               viral dna takes over

lysogenic     virus does not destroy host cell

lytic               virus destroys host cell

lytic               induces symptoms of viral infection

lysogenic       cell reproduces and spreads provirus

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%.