Download Practice Exam II-1 _ _1. The arrows in the pathway represent? a

Practice Exam II-1
_ _1. The arrows in the pathway represent? a. sugars b. enzymes c. promoters d. messages
___2. They are: a. nucleic acids
b. vitamins
c. proteins
d. lipids
___3. which are built from? a. nucleotides
b. bases
c. carbohydrates
d. amino acids
___ 4. At least ? genes are needed to convert tyrosine to iodothyroxine
a. 1
b. 2
c. 3
d. 4
e. cannot be determined
___5. The "arrow" missing in phenylketonuria is? a. #2
b. #5
c. #7
d. #14 e. not shown
6. ___A missing "arrow" is almost always inherited as a(n): a. a simple recessive b. simple
dominant
c. incomplete dominant
d. polygenic trait
e. other
7. ___The phenotype of a person lacking either "arrow" 6 or 7 is:
a. normal
b. tyrosinosic c. albino
d. too much DOPA
8.___ If a pure breeding female rat lacking "arrow" 6 is crossed to a pure breeding male lacking
"arrow" 7, the progeny will be: a. normal b. albino
c. tyrosinosic d. born dead
___9. If the progeny in question 8 are intercrossed, their offspring will show:
a. epistasis
b. lack of penetrance c. 3 normal:1 albino d. all alike
___10. Phenylketonuria can be treated by: a. Nutrasweetª b. antibiotics c. a special dietd. a
shot of phenylalanine hydrolase
e. no known method
___11. If Iodothyroxin production is regulated by feedback inhibition, the regulated step is
expected to involve "arrow"? a. #5 b. #8 c. #9 d. #10 e. several ___
12. The compound which would accumulate in a mutant missing #12 is:
a. Dietary protein
b. Tyrosine c. p-HPA
d. DHPA
II. Given the base sequence:
5' AUGCAUGCACCAGAGCGAUGGUGAAAAAAAAAAAAAAAAA 3'
A. Do you think it is DNA or RNA?____Why?
B. Is it from a higher organism or a prokaryote?_______ How do you know?
C. Show the base sequence which served as a template to make this strand
D. Translate the given strand
E. Write the third codon you used, and show the expected anticodon
on a line drawing of the molecule where it is found.
III..Provide a short answer to each of the following questions.
A.
1. The t in tRNA stands for?_______________
2. The r in rRNA stands for?_______________
3.The m in mRNA stands for?_______________
B.1. What kind of chemical mutagen is used as an anti-tumor drug?_______
2.What is the rationale?
C. What does the statement "It was positive in the Ames test" tell you?
D. Nitrites can be converted to mutagens in the stomach, yet nitrites are used as a food additive.
Would removing nitrites from food be a "cure-all"? ______ Explain your answer
Fill the blanks-Each mutation affects the same codon.
SOURCE
CODON
CODES FOR
TYPE OF MUTATION
normal
CAG
________
none
mutant 1
________
________
nonsense
mutant 2
________
Glu
________
mutant 3
CAA
________
_________
G. Amino acid #54 in 3 different samples of ß-globin was His, Asp, and Ile. If one sample came
from a lion, another a tiger, and the other a camel, which sample do you think came from the
camel?______ Why?
H. List 3 "agents" that have proven to be mutagenic.
1._______________ 2___________________ 3___________________
I. What are persons with the following genetic defects sensitive to? Why?
A. Xeroderma pigmentosum _____________
B. Ataxia telangiectsia ________________
Why are they sensitive? ________________________________
IV Gene Regulation Shown below are a number of strains of E. coli showing the map of the lac
operon. A minus superscript (ex. Z ) means that the gene or map region is non- functional. In
column one tell whether ß-galactosidase (Z gene product) will be regulated (R), constitutive.(C),
or never made (A). Do the same in column 2 for the permease (Y gene product).
STRAIN
ß-GALACTOSIDASE
PERMEASE
EX. P i P O Z Y A
___R_____
____R____
__________
_________
__________
_________
__________
_________
__________
_________
__________
_________
__________
_________
__________
__________
__________
__________
-
1. P i P O Z Y A
-
2. P i P O Z Y A
-
-
3. P i P O Z Y A
-
-
4. P i P O Z Y A
-
-
5. P i P O Z Y A
-
6. P i P O Z Y A
-
-
7. P i P O Z Y A
-
PiPOZY A
-
-
8. P i P O Z Y A
PiPOZYA