hi,took nbme 1 and found these questions for which i want answers and explanations
1.a 50yr old man had MI,dignosed as familial hypercholesterolemia(AD).Son not tested yet,what is the probability of this man's granddaughter to get this disease thro son
a)less than1% b)25%c)50%d)10%e)33%

2.normal children are able to mount responses to variable no of antigens.this is possible by which of the following DNA mechanism
a)amplification b)recombination c)conformation d) repair e)replication

3)
ΔG0′
V ↔ W – 4.0
W ↔ X +0.4
X ↔ Y – 3.4
Y ↔ Z + 5.7

From the values of ΔG0′ given in the table, which compound in the overall metabolic pathway V ↔ W ↔ X ↔ Y ↔ Z will accumulate in the largest amount at equilibrium?

A) V
B) W
C) X
D) Y
E) Z

4)(Cleft lip picture)…..The developmental anomaly shown in this stillborn fetus is most commonly characterized by which type of inheritance?

A) Autosomal dominant

B) Autosomal recessive

C) Mitochondrial

D) Multifactorial

E) Sex-linked

5)
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


6) sorry I am not able to post the pedigree chart.hope you remember.In the family represented by the pedigree, affected persons have a disease characterized by mitochondrially inherited late-onset optic atrophy. Assuming that the family and personal medical history of the partner is unremarkable, the risk for optic atrophy to develop in the male child of IV-9 is closest to

A) 0%
B ) 25%
C ) 50%
D ) 75%
E ) 100%

can someone explain number three?

For a reaction to be in equilibrium, delta G naught needs to be zero. If it is a negative value, then the reaction is spontaneous. If it is positive, it is not. So the reaction with the largest positive value will be the least favorable, and most likely to accumulate in substrate. Since Y going to Z has the largest positive value, then the choices can be narrowed down to those two. Now this is where I get stumped: Which one will accumulate, Y or Z, as it is shown as a reversible rxn?

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I used to pray and pray for a bike and never got one. Later I learned that God doesn't work that way... so I went out and stole a bike and asked God for forgiveness.

I think the answer is Y - thanks for the explanation helps.

Thanks, but you might want to check it out in your biochem notes/text to be sure. Just seeing the words "Nernst equation" in a practice question recently gave me an ocular muscle twitch, LOL!

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I used to pray and pray for a bike and never got one. Later I learned that God doesn't work that way... so I went out and stole a bike and asked God for forgiveness.

you couldve jus posted q's instead of mentioning where its from. you may be violating copyrights. i have read several times that they do track u and the penalty would do some damage to ur eligibility to take step1, etc.

__________________
Discharge status: Alive but w/out permission
SJSM'09

Dr.X, I thought the penalties were more for those that disclose detailed descriptions of the content on the actual currently administered Step 1? People get in trouble for discussing the practice q's too?

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I used to pray and pray for a bike and never got one. Later I learned that God doesn't work that way... so I went out and stole a bike and asked God for forgiveness.

sorry to stray off topic OP. ive read stuff like this on different occasions. this particular one is from SDN moderator's post:

Important Notice from the NBME

The materials (i.e., test questions, clinical computer simulations, and standardized patient cases) of the USMLE, NBME’s self-assessment program and NBME subject examinations are copyrighted. Publishing any ‘remembered’ materials or replicas of these materials on The Student Doctor Network (or any other forum) is an unauthorized reproduction of NBME’s materials, constitutes copyright infringement and is strictly prohibited. Any violation of NBME’s copyrights and trademarks can not only lead to legal sanctions, but can also have professional consequences. Medical students and medical school graduates, prospective students, examinees of the USMLE and NBME self-assessment examinations and subject examinations are reminded that they are bound to the terms they agreed to follow regarding disclosure of intellectual property prior to the administration of one of these examinations. Failure to adhere to the terms of these policies will subject an individual to various penalties up to and including being barred from future USMLE examinations.

__________________
Discharge status: Alive but w/out permission
SJSM'09

Personally, i love to get exposure to hy questions as much as possible. i carry a printout thats bigger than any medical textbook in my car and its all composed of tommyk questions. many thanks to him, whenever i wait in the car i go through it pages after pages and it never seems to end...

in btw mdiva, i had a similar rxn too when i saw nernst eq.. i cant believe i gotta go review all that again from kaplan.

__________________
Discharge status: Alive but w/out permission
SJSM'09