1. 1977:

Proteins are composed of amino acid subunits which form stable

three-dimensional structures.

a. Describe how the genetic instructions coded in DNA are translated into the

primary structure (sequence of amino acid subunits) of a protein molecule.

b. Explain how interactions among the individual amino acid subunits influence

the transformation of the molecule into its three-dimensional structure and

how they stabilize it.

2. 1985:

Describe the operon hypothesis and discuss how it explains the control of
messenger RNA production and the regulation of protein synthesis in

bacterial cells.

3. 1993:

Assume that a particular genetic condition in a mammalian species causes an

inability to digest starch. this disorder occurs with equal frequency in males

and females. In most cases, neither parent of affected offspring has the condition.

(a) Describe the most probable pattern of inheritance for this condition. Explain

your reasoning. Include in your discussion a sample cross(es) sufficient to

verify your proposed pattern.

(b) Explain how mutation could cause this inability to digest starch.

(c) Describe how modern techniques of molecular biology could be used to

determine whether the mutant allele is present in a given individual.

4. 1976:

Each year a number of children are born with biological defects that impair normal
            function. For THREE of the following conditions, discuss such aspects as the biological
            cause, the methods of treatment and possible means of detection and/or prevention.

a. Phenylketonuria (PKU)

b. Sickle cell anemia

c. Down syndrome

d. Cretinism

e. Erythroblastosis fetalis

f. Blue-baby condition

g. Tay-Sachs

5. 1996:

An organism is heterozygous at two genetic loci on different chromosomes.

a) Explain how these alleles are transmitted by the process of mitosis to daughter cells.

b) Explain how these alleles are distributed by the process of meiosis to gametes.

c) Explain how the behavior of these two pairs of homologous chromosomes during

meiosis provides the physical basis for Mendel’s two laws of inheritance.

Labeled diagrams that are explained in your answer may be useful.

6. 1995:

The diagram below shows a segment of DNA with a total length of 4,900 base

pairs. The arrows indicate reaction sites for restriction enzymes (enzyme X

and enzyme Y).

(A) Explain how the principles of gel electrophoresis allow for the separation

of DNA fragments.

(B) Describe the results you would expect from the electrophoretic

separation of fragments from the following treatments of the DNA

segment above. Assume that the digestions occurred under appropriate

conditions and went to completion.

I DNA digested with only enzyme X

II. DNA digested with only enzyme Y

III. DNA digested with enzyme X and enzyme Y combined

IV. Undigested DNA

(C) Explain both of the following.

(1) The mechanism of action of restriction enzymes.

(2) The different results you would expect if a mutation occurred

at the recognition site for enzyme Y.