what to do
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23. A 50-year-old man who recently immigrated to the USA from Russia develops fever, swelling of the neck, and difficulty swallowing. His vaccination history is uncertain. Examination of the throat shows a gray membrane across the pharynx. The pathogen responsible for this infection most likely acquires its virulence through which of the following genetic events?
A ) Acquisition of a transposon
B ) Chromosomal mutation
C ) Conjugation
D ) Recombination
E ) Transduction
38. A female neonate has profound hypotonia. The only known complication of pregnancy was polyhydramnios. The mother has a lack of facial expression and weak muscles; she says she did not have any problems as an infant or child. Which of the following best explains the difference in presentations in the mother and child?
A ) Anticipation
B ) Delayed onset
C ) Genetic heterogeneity
D ) Incomplete penetrance
E ) Pleiotropy
33. A 17-year-old boy with moderate mental retardation has macro-orchidism. Cytogenetic analysis shows a fragile site on the long arm of chromosome X. Which molecular defect is most likely associated with this abnormality?
A ) CGG repeat expansion
B ) Exon deletion
C ) Gene amplification
D ) Point mutation
E ) Splice site mutation
50. Normal healthy children are able to mount diverse antibody responses to several thousands of different antigens. This process is based primarily on which of the following DNA mechanisms?
A ) Amplification
B ) Conformation
C ) Recombination
D ) Repair
E ) Replication
i need the answers. plz guys and ladies, help me out
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saif
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| NE
Forum Guru
Topics: 53
Posts: 504
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23-C
38-E
33-A
50C
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| medocuk
IM-RES
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NE..can you give your diagnosis and explain the reson for answer selection.Thanks.
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| Ancylostoma
Forum Guru
Topics: 42
Posts: 642
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23-E is transduction, diptheria gets its toxin from a bacteriophage
38-is A, pleitropy is one mutation that effect miultiple organ systems but it doesnt explain the difference in presentations, answer is anticipation. In anticipation with each generation the disease presents earlier are is worse then it was the past generation.
33-a pure memory,
50 c- recombination of genes in creations of immunoglobulins and tcel receptops (V, D, J, heavy chain , light chain etc)
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| laura81
Forum Elite
Topics: 32
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what is the dissease in 38?
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| borrelia
Forum Newbie
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23 Do not have any idea!!!! why is it E? where can i read that? 
38 A in anticipation, the individuals of most recent generations are severly affected (more than the previous generations) and sooner in their life, that can be explain becaus of gradual expansion of trinucleotide (trinucleotide repeat polymorphism, the chain gets larger in each generation)
33 A In fragil X syndrome the major mutation is an expanded CGG in the 5' of the untranslated region of FMR1 gene (from kaplan notes)
40 C
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| lq2006
Forum Elite
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E
A
A
C
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| yoga
usmlelogy professor
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38-a
33-a
50-c
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we are all in the gutter but some of us looking at the stars
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| drgho
Forum Junior
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E.
A.
A.
C.
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| edie
I can, and I will.
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38 is definitely A. Disease is myotonic dystrophy. Check it:
from http://ghr.nlm.nih.gov/condition=myotonicdystroph...
How do people inherit myotonic dystrophy?
Both types of myotonic dystrophy are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one affected parent.
As myotonic dystrophy is passed from one generation to the next, the disorder generally begins earlier in life and signs and symptoms become more severe. This phenomenon is called anticipation. In type 1 myotonic dystrophy, anticipation is caused by an increase in the length of the unstable region in the DMPK gene. In type 2 myotonic dystrophy, a longer unstable region in the CNBP gene does not appear to influence the age of onset of the disorder. The cause of the anticipation observed in families with type 2 myotonic dystrophy is unknown.
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