1. Chromosome 21:
a. is the shortest chromosome
b. is acrocentric
c. is in the A group of chromosomes
d. carries the gene for growth hormone.
e. trisomy causes Down's syndrome
2. The following are true about the Y chromosome:
a. the long arm is referred to as the p arm
b. the long arm has variable length
c. it demonstrates fluorescence with quinacrine
d. the short arm contains gene for testicular formation
e. fragile Y chromosome is associated with mental
retardation.
3. In the DNA structure:
a. the backbone is made up of an alternate molecule
of pentose sugar and phosphate.
b. most coils are left-handed
c. there is a terminal hydroxyl group at one end
of the chain
d. there is a terminal phosphate group at only one
end of the chain.
e. if one chain has -AGG- the other chain has
the sequence -TCC-.
4. The following are true:
a. Turner's syndrome is usually due to non-dysjunction
in the spermatozoon
b. half the daughters of Turner's syndrome are
affected by the same condition
c. patients with XXY are infertile
d. all daughters are carriers in X-linked dominant disease
e. the recurrence rate for polygenetic conditions is 1-5%
5. The following are true about cytoplasmic messenger RNA:
a. it is mainly translated from nuclear DNA
b. has a larger molecular weight than heterogeneous
RNA
c. contains uracil in place of thymine
d. the sugar moeity is deoxyribose.
e. is manufactured when the embryo is at the one
cell stage