1/10
A healthy couple, who recently emigrated from Eastern Europe, bring their 3-year-old son to the office for evaluation of an eczematous rash. On examination, the child also shows signs of intellectual disability gait abnormality and has a musty body odor. What is the likelihood that this couple's next child will be a with the same disease?
- Same as the general population
- 1/32
- 1/16
- 1/8
- 1/4
- 1/2
2/10
A 15-year-old patient is referred to the physician by a teacher who is concerned about the patient's learning abilities and behavior. The patients reading and writing skills are significantly impaired compared to other classmates, and the patient often misbehaves in class despite receiving numerous detentions. Neuropsychological assessment shows mild intellectual disability. Cytogenetic studies show a karyotype containing 47 chromosomes. Which of the following findings are most likely to be present on further evaluation?
- Arachnodactyly, scoliosis, aortic root dilation
- Macroorchidism, large jaw and ears
- Short stature, broad chest, amenorrhea
- Short stature, hypotonia, obesity
- Tall stature, gynecomastia, azoospermia
3/10
A 17-year-old girl is brought to the physician by her parents for failure to undergo menarche. She has 2sisters, both of whom began menstruating before the age of 16. Physical examination shows a short and stocky girl with a thick neck, square chest, and widely spaced nipples. The physician refers the girl for karyotype analysis, which shows 45, XO. During a meeting with the girl and her parents to diagnosis, the parents express concern over their daughter's future chances to conceive. Which of following is the most appropriate response?
- Pregnancy is medically impossible for her
- She can conceive, but will likely require treatment with gonadotrophins
- Pregnancy is risky and contraindicated in her condition.
- She can become pregnant, but will likely require an oocyte donation
- She has the same chances of pregnancy as the general population
4/10
A 10-year-old girt is brought to the physician for evaluation of short stature. She was an average-sized infant, but over the past few years, her height growth velocity has plateaued. The patient has not menstruated and has no symptoms. She takes no medications, has no allergies, and received all recommended immunizations. Her mother had menarche at age 14; both of her parents are tall. The patient's height is at the<5th percentile, and weight is at the 50th percentile for age and sex. She has no breast buds and no axillary or pubic hair. She has a low hairline, a short and wide neck, a broad chest, and widely-spaced nipples. Which of the following is the most likely underlying mechanism for this patient's condition?
- Balanced translocation
- Frameshift mutation
- Meiotic nondisjunction
- Trinucleotide repeat expansion
- Uniparental disomy
5/10
A newborn girl is evaluated in the nursery after an uncomplicated spontaneous vaginal delivery to a 29-year-old primigravida. The mother declined prenatal testing and ultrasound examination during the pregnancy. Her pregnancy was otherwise uneventful, and she took prenatal vitamins throughout. Examination of the neonate shows a posterior neck mass and bilateral nonpitting edema of the hands and feet. Femoral pulses are diminished. Neck ultrasound reveals a mass composed of cystic spaces sepatated by connective tissue. Which of the following is the most likely underlying mechanism patient's condition?
- 21 -hydroxylase deficiency
- Androgen receptor mutation
- Loss of paternal chromosome X
- Meiotic nondisjunction of fetal chromosome 18
- Partial deletion of the short arm of chromosome 5
- Robertsonian translocation involving fetal chromosome 21
6/10
A 15-year-old girl is brought in for evaluation of amenorrhea. She has never menstruated, but her mother had menarche at age 14. The patient has no other medical problems or allergies. She takes no medications and does not use tobacco, alcohol, or drugs. The patient plays the violin for her high school orchestra and is the captain of her junior varsity tennis team. She is not sexually active. Her height is 175 cm (5 ft 8 in), weight is 65 kg (143 lb), and BMI is 21.2 kg/m2. Examination shows fully developed secondary sexual characteristics. Pelvic ultrasound shows a shortened vaginal canal with a rudimentary uterus. Which of the following is the most likely diagnosis in this patient?
- 21-hydroxylase deficiency
- 47,XXX karyotype
- Androgen insensitivity syndrome
- Kallmann syndrome
- Klinefelter syndrome
- Turner syndrome
- Vaginal agenesis
7/10
A mutation that leaves prokaryotes unable to replicate their DNA is induced in an experimental setting. The ability to remove RNA primers during DNA replication is affected by this experimental mutation. Which of the following enzymes is most likely nonfunctional?
- Helicase
- Primase
- Gyrase
- DNA polymerase III
- DNA polymerase
- Ligase
8/10
8. Precursor mRNA undergoes substantial post-transcriptional processing before it becomes the finalized mRNA template. Because of this extensive processing, the final mRNA sequence can be different from that of its encoding DNA. An mRNA molecule transcribed from a eukaryotic gene is shown schematic below. Which of the following portions is not transcribed from the DNA template?
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- A
- B
- C
- D
- E
9/10
A mutation in the TATA box of a eukaryotic gene that codes for a transmembrane protein is most likely to affect which of the following functions?
- DNA methylation
- Transcription initiation
- Translation initiation
- RNA elongation
- Posttranscriptional RNA splicing
- Polypeptide folding following translation
10/10
A 34-year-old woman with a history of chronic urinary tract infections comes to the office complaining of dysuria. A urine sample is obtained and sent for culture. Gram-negative bacteria isolated from the urine are found to form pink colonies on lactose-containing media. Several days later, bacterial isolates from a new urine sample do not ferment lactose due to the genomic change is most consistent with which of the following:
- Conservative mutation
- Missense mutation
- Nonsense mutation
- Silent mutation
- Frameshift mutation
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