NR-283 Pathophysiology - Set 2 - Part 3

Correct Answer: Half of sons affected, half of daughters carriers

A carrier mother passes her abnormal X to half her children. A son receiving it has no second X to compensate and bleeds, while a daughter receiving it becomes a healthy carrier. Option a is incorrect because daughters inherit a normal X from their father, which masks any abnormal maternal copy. Affected daughters would require an affected father as well, and that is uncommon. Option b is incorrect because the mother has one normal X and one abnormal X, and chance decides which she donates. Roughly half her sons receive the normal copy and never develop bleeding problems. Option d is incorrect because a flat fifty percent figure applied to all children describes autosomal dominant transmission. X linkage forces the answer to be stated separately for each sex, since males are hemizygous.

Correct Answer: It finds disorders where early treatment prevents damage

Newborn screening targets conditions such as phenylketonuria, congenital hypothyroidism, and galactosemia, where starting treatment within the first days prevents permanent injury. An infant found later has already sustained irreversible harm. Option a is incorrect because chromosome analysis requires a karyotype ordered for a specific reason, not a routine dried blood spot. The panel measures metabolites and hormones rather than counting chromosomes. Option b is incorrect because placental performance is judged during pregnancy through growth measurements, fetal monitoring, and ultrasound. Nothing in the newborn blood spot looks backward at how the placenta behaved. Option c is incorrect because screening detects inherited metabolic and endocrine disease and confers no protection against infection. The infant still needs the full immunization schedule beginning with hepatitis B before discharge.

Correct Answer: Reduced oxygen delivery driving compensatory cardiac and respiratory effort

Anemia lowers oxygen carrying capacity, so tissues become hypoxic. The heart speeds up and the lungs work harder to move what oxygen remains, while blood shunts away from skin, producing pallor and fatigue. Option a is incorrect because dilution from excess plasma lowers the hemoglobin reading without reducing total red cell mass. That picture belongs to fluid overload or pregnancy, and it does not account for the pallor described here. Option b is incorrect because immature white cells entering circulation signal marrow stress or leukemia, not a low hemoglobin. Nothing in this scenario points toward a white cell abnormality, and white cells carry no oxygen. Option d is incorrect because thickened blood occurs when red cell numbers rise, as in polycythemia. Anemia thins the blood instead, which lowers viscosity and speeds flow, and that is why a flow murmur may appear.

Correct Answer: Hypokalemia from ongoing loop diuretic therapy

Loop diuretics waste potassium in the urine. Low potassium leaves muscle less responsive, so cramps and weakness appear, and smooth muscle in the gut slows until distention and ileus develop. Digoxin toxicity risk rises too. Option a is incorrect because potassium builds up in renal failure, aldosterone deficiency and potassium sparing drugs, none of which is present. Furosemide moves potassium in the other direction entirely. Option c is incorrect because a high calcium level brings lethargy, stupor, polyuria, thirst and kidney stones rather than cramping muscles. Malignancy, hyperparathyroidism or immobility would need to be in the story. Option d is incorrect because excess magnesium depresses the neuromuscular system, producing sluggish reflexes, drowsiness, bradycardia and dangerous respiratory depression. It also requires failing kidneys or magnesium containing products to develop.

Correct Answer: "No amount of alcohol is safe at any point."

The brain develops from the third week until after birth, so alcohol injures neurons throughout pregnancy. No threshold dose has been established, which makes complete abstinence the only defensible teaching. Option a is incorrect because organogenesis ending does not end the danger. Growth restriction and the lasting attention, memory, and impulse control problems of fetal alcohol spectrum disorder come mainly from later exposure. Option b is incorrect because ethanol is ethanol whatever the drink. A standard glass of wine, a beer, and a shot of spirits deliver roughly the same dose to the fetal circulation. Option c is incorrect because setting a daily allowance implies a safe threshold that research has never identified. Guidance for the second trimester is identical to guidance for the first, namely none at all.

Correct Answer: X linked recessive, because fathers never transmit an X

A father gives his son a Y chromosome, never an X, so X linked alleles cannot travel from father to son. Transmission through healthy daughters to affected grandsons completes the fingerprint. Option b is incorrect because autosomal recessive disease strikes girls and boys in equal numbers. A chart in which only males are affected points away from an autosome and toward the X chromosome. Option c is incorrect because the dominant form on the X makes every daughter of an affected man symptomatic. Here the intervening women stay well, which fits a recessive allele masked by their normal X. Option d is incorrect because dominant autosomal traits appear in unbroken succession with affected parents producing affected children of either sex. Skipping through well women and sparing all females contradicts that straightforward vertical pattern.

Correct Answer: Down syndrome from an extra chromosome twenty one

Hypotonia with a flat facial profile, upslanting palpebral fissures, epicanthal folds, macroglossia, and a single transverse palmar crease is the classic trisomy twenty one picture. Karyotype confirms the extra chromosome. Option a is incorrect because monosomy X occurs only in girls and announces itself with puffy hands and feet plus loose neck skin. Facial flattening and a protruding tongue are not part of it. Option b is incorrect because trisomy eighteen presents with clenched hands whose fingers overlap, rocker bottom feet, a prominent occiput, and a small jaw. Those infants are usually rigid rather than floppy. Option c is incorrect because deletion of the short arm of chromosome five gives a high pitched cat like cry, microcephaly, and a round moon face. No such cry is described here.

Correct Answer: Immature blasts crowding the marrow and suppressing normal production

Leukemic blasts multiply without control and take over the marrow space. Normal red cell, platelet, and neutrophil production is squeezed out, and the blasts themselves cannot fight infection, so the client is anemic, bleeding, and septic. Option b is incorrect because immune platelet destruction lowers the platelet count alone, leaving hemoglobin and white cells untouched. It also could never explain a white count approaching one hundred thousand. Option c is incorrect because widespread clotting with factor consumption describes disseminated intravascular coagulation. That syndrome shows a prolonged prothrombin time and a falling fibrinogen, neither of which is reported for this client. Option d is incorrect because plasma cell tumors carve punched out holes in bone and drive calcium up. Their hallmark is deep back pain with fractures, and the white count in that disease is not enormous.

Correct Answer: Nondisjunction during separation of chromosome pairs

Nondisjunction is failure of a chromosome pair to separate during anaphase, so one gamete receives twenty four chromosomes and the other twenty two. Fertilization by a normal gamete then yields a trisomic zygote. Option a is incorrect because crossing over exchanges matching segments between homologous chromosomes in prophase one, generating diversity while leaving the total count intact. Nothing about that swap adds a whole chromosome to a gamete. Option c is incorrect because a point mutation swaps one base for another inside a gene. Sickle cell disease arises that way, yet the chromosome number stays at forty six and no karyotype change appears. Option d is incorrect because balanced translocation moves material to a different chromosome without gain or loss. The carrier stays healthy, and gene dosage remains correct, so no extra chromosome reaches the fertilized egg.

Correct Answer: Coarctation of the aorta or bicuspid valve

Turner syndrome combines short stature, streak ovaries with primary amenorrhea, webbed neck, and newborn lymphedema. Cardiac lesions occur in a third to a half, so echocardiography for coarctation and bicuspid valve is essential. Option a is incorrect because streak gonads make almost no sex hormone at all, which is precisely why puberty stalls. Estrogen replacement, not androgen excess, is what these girls eventually require. Option b is incorrect because intelligence in monosomy X is typically normal, with only nonverbal and visuospatial weaknesses reported. Deteriorating cognition belongs to other conditions and would not be expected as she grows. Option d is incorrect because loss of a growth gene on the missing X keeps these girls short, and growth hormone is given as treatment rather than found in excess. Tall stature suggests an extra X in a male.