Growth and Development — MCQs

Growth and Development Indian Medical PG Practice Questions and MCQs

Question 471: The following clinical features are seen in which disease?

A. Turner syndrome
B. Fragile X-syndrome
C. Achondroplasia
D. Down syndrome (Correct Answer)

Explanation: ***Down syndrome*** - Classic features include **upslanting palpebral fissures**, **epicanthal folds**, **flat facial profile**, and **single palmar crease** (simian crease). - Associated with **hypotonia**, **intellectual disability**, and increased risk of **congenital heart defects** and **duodenal atresia**. *Turner syndrome* - Characterized by **short stature**, **webbed neck**, **shield chest**, and **lymphedema** in females. - Associated with **ovarian dysgenesis**, **coarctation of aorta**, and **45,X karyotype**, not the facial features described. *Fragile X-syndrome* - Features include **long face**, **prominent ears**, **macroorchidism** in males, and **intellectual disability**. - Caused by **FMR1 gene mutation** leading to absence of **FMRP protein**, not chromosomal trisomy. *Achondroplasia* - Presents with **disproportionate short stature**, **rhizomelic shortening** of limbs, and **macrocephaly**. - Caused by **FGFR3 gene mutation** affecting **cartilage formation**, without the typical facial dysmorphism of trisomy 21.

Question 472: What is the normal respiratory rate in a child less than 2 months old?

A. 60 breaths per minute (Correct Answer)
B. 50 breaths per minute
C. 40 breaths per minute
D. 30 breaths per minute

Explanation: **Explanation:** The respiratory rate in children varies significantly with age, gradually decreasing as the child matures. According to the **Integrated Management of Neonatal and Childhood Illness (IMNCI)** guidelines, the threshold for defining tachypnea (fast breathing) is age-specific. **1. Why Option A is Correct:** In a child **less than 2 months old**, the normal upper limit of the respiratory rate is **60 breaths per minute**. A rate of 60 or more is classified as tachypnea in this age group. It is important to count the rate for one full minute when the infant is calm, as periodic breathing is common in neonates. **2. Analysis of Incorrect Options:** * **Option B (50 bpm):** This is the threshold for tachypnea in children aged **2 months to 12 months**. A rate of 50 or more in this group indicates fast breathing. * **Option C (40 bpm):** This is the threshold for tachypnea in children aged **1 year to 5 years**. * **Option D (30 bpm):** This is generally considered the upper limit of normal for older children (school-age) and adolescents. **Clinical Pearls for NEET-PG:** * **IMNCI Cut-offs for Tachypnea:** * < 2 months: ≥ 60 bpm * 2–12 months: ≥ 50 bpm * 1–5 years: ≥ 40 bpm * **High-Yield Fact:** If a child less than 2 months old has a respiratory rate of exactly 60 bpm, it is considered tachypnea. However, for children older than 2 months, the "equal to" sign also applies (e.g., exactly 50 bpm at 5 months is tachypnea). * **Observation Tip:** Always look for chest indrawing along with the respiratory rate to assess the severity of respiratory distress (Pneumonia vs. Severe Pneumonia).

Question 473: All of the following are true statements about Down syndrome, except:

A. Most common inheritable cause of mental retardation
B. In quadruple test, Inhibin-A level is reduced (Correct Answer)
C. Most common cause is meiotic non-disjunction
D. In triple test (AFP |, estriol |, hcG |)

Explanation: **Explanation:** The correct answer is **B**, as Inhibin-A levels are actually **increased**, not reduced, in Down syndrome. **1. Why Option B is the correct choice (The Exception):** In the prenatal screening for Down syndrome (Trisomy 21), the **Quadruple Test** (performed between 15-20 weeks) shows a specific pattern. In Down syndrome, **Inhibin-A** and **hCG** levels are **elevated** (High), while Alpha-fetoprotein (AFP) and Unconjugated Estriol (uE3) are **decreased** (Low). A mnemonic to remember this is **"HI"** (hCG and Inhibin are High). **2. Analysis of other options:** * **Option A:** While Fragile X syndrome is the most common *inherited* cause, Down syndrome is the most common **genetic/chromosomal** cause of intellectual disability. In the context of NEET-PG, this is a standard factual statement. * **Option C:** Approximately **95%** of Down syndrome cases are caused by **meiotic non-disjunction** (mostly maternal), making it the most common underlying mechanism. * **Option D:** The **Triple Test** pattern for Down syndrome is characterized by low AFP, low Estriol, and high hCG. This is a classic diagnostic finding. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cardiac defect:** Atrioventricular Septal Defect (Endocardial cushion defect). * **First-trimester screening:** Shows **increased Nuchal Translucency (NT)** and **decreased PAPP-A**. * **Cytogenetics:** 95% due to Trisomy 21 (Non-disjunction), 4% due to Robertsonian Translocation (usually t14;21), and 1% due to Mosaicism. * **Gastrointestinal association:** Duodenal atresia ("Double bubble" sign) and Hirschsprung disease.

Question 474: Which of the following reflexes is not present at birth?

A. Asymmetric Tonic Neck Reflex
B. Moro's Reflex
C. Symmetric tonic neck reflex (Correct Answer)
D. Crossed extensor reflex

Explanation: **Explanation:** The correct answer is **Symmetric Tonic Neck Reflex (STNR)** because it is a "developmental" reflex rather than a "primitive" reflex present at birth. **1. Why STNR is the correct answer:** Unlike most primitive reflexes that are present at birth and integrated later, the STNR **appears between 6 to 9 months of age**. It plays a crucial role in helping the infant transition from a prone position to crawling. When the neck is flexed, the arms flex and legs extend; when the neck is extended, the arms extend and legs flex. It typically disappears (integrates) by 9 to 12 months. **2. Analysis of Incorrect Options:** * **Asymmetric Tonic Neck Reflex (ATNR):** Present at birth, it peaks at 2 months and disappears by 4–6 months. It is characterized by the "fencing posture" when the head is turned to one side. * **Moro’s Reflex:** A key primitive reflex present at birth. It disappears by 3–6 months. Its absence at birth suggests CNS depression or birth injury, while persistence beyond 6 months suggests cerebral palsy. * **Crossed Extensor Reflex:** A spinal reflex present at birth. When one leg is extended and the sole is stimulated, the opposite leg flexes, adducts, and then extends. It disappears by 1–2 months. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest reflex to appear:** Palmar grasp (appears at 28 weeks of gestation). * **Reflexes appearing at birth:** Moro’s, Rooting, Sucking, Palmar grasp, ATNR, and Plantar grasp. * **Parachute Reflex:** The most important protective reflex; it appears at 6–9 months and **persists for life**. * **Persistence of primitive reflexes** beyond their expected age of disappearance is a sensitive early indicator of upper motor neuron lesions or Cerebral Palsy.

Question 475: At what age does a child's intracellular fluid (ICF) and extracellular fluid (ECF) composition become similar to that of an adult?

A. 1 year (Correct Answer)
B. 2 years
C. 3 years
D. 4 years

Explanation: **Explanation:** The distribution of body water undergoes significant changes from birth through infancy. At birth, a neonate has a high Total Body Water (TBW) content (approx. 75-80%), with a predominant **Extracellular Fluid (ECF)** volume (approx. 45%) compared to **Intracellular Fluid (ICF)** (approx. 35%). As the child grows, the TBW percentage decreases, and the ratio shifts. The ECF volume rapidly declines during the first few months of life due to postnatal diuresis and the growth of cellular mass. By the age of **1 year**, the proportion of ECF and ICF reaches adult-like levels, where ICF becomes the larger compartment (approx. 40% of body weight) and ECF stabilizes (approx. 20-25% of body weight). **Analysis of Options:** * **Option A (1 year):** Correct. This is the physiological milestone where the transition from ECF-dominance to ICF-dominance is complete, mirroring adult body water distribution. * **Options B, C, and D:** These are incorrect because the most dramatic shifts in fluid compartments occur within the first 12 months. While TBW continues to decline slightly until puberty, the fundamental ICF/ECF ratio is established by the end of the first year. **High-Yield Clinical Pearls for NEET-PG:** * **Preterm Infants:** Have the highest TBW (up to 90%) and ECF volume, making them extremely vulnerable to fluid loss and electrolyte imbalances. * **Dehydration Risk:** Infants are more prone to dehydration than adults because their ECF (the "available" fluid for loss) is larger relative to their total weight, and they have a higher surface-area-to-mass ratio. * **Adult Composition:** TBW is ~60% in males and ~50% in females (due to higher fat content).

Question 476: Delayed dentition is usually considered when there are no teeth by what age?

A. 18 months
B. 9 months
C. 16 months
D. 13 months (Correct Answer)

Explanation: **Explanation:** The eruption of the first primary tooth (usually the lower central incisor) typically occurs between **6 to 8 months** of age. While there is significant physiological variation, **delayed dentition** is clinically defined as the absence of any teeth by **13 months** of age. * **Why 13 months is correct:** Standard pediatric guidelines (including Nelson’s and OP Ghai) define the upper limit of normal for the eruption of the first tooth as 13 months. If no teeth have erupted by this age, a clinical evaluation for underlying systemic or genetic causes is warranted. * **Why other options are incorrect:** * **9 months:** This is within the normal range for many healthy infants. * **16 and 18 months:** These ages are significantly beyond the diagnostic threshold. Waiting until 18 months would delay the diagnosis of potential underlying conditions like hypothyroidism or rickets. **High-Yield Clinical Pearls for NEET-PG:** 1. **Sequence:** The first teeth to erupt are the **lower central incisors**, followed by the upper central incisors. 2. **Order of Primary Teeth:** Central Incisor → Lateral Incisor → First Molar → Canine → Second Molar. 3. **Total Count:** By **2.5 to 3 years**, all 20 primary (deciduous) teeth should have erupted. 4. **Common Causes of Delayed Dentition:** * **Idiopathic** (Most common) * **Nutritional:** Rickets (Vitamin D deficiency) * **Endocrine:** Hypothyroidism, Hypopituitarism * **Genetic/Syndromic:** Down syndrome, Cleidocranial dysplasia, Ectodermal dysplasia. 5. **Formula for number of teeth (6–24 months):** Age in months – 6.

Question 477: By what age do teeth typically begin to erupt in primary dentition?

A. 6 weeks
B. 12 weeks
C. 6 months (Correct Answer)
D. 12 months

Explanation: **Explanation:** The correct answer is **6 months**. **1. Why 6 months is correct:** In primary (deciduous) dentition, the first tooth to erupt is typically the **lower central incisor**, which usually appears at approximately **6 months** of age. While there is a normal physiological range (4 to 10 months), 6 months is the standard milestone used in pediatric assessments and competitive exams. The general rule of thumb for primary dentition is that approximately one new tooth erupts for every month of age starting from the 6th month until all 20 teeth are present by 2.5 to 3 years. **2. Why the other options are incorrect:** * **6 weeks & 12 weeks (A & B):** These are too early for normal eruption. Teeth present at birth are called *natal teeth*, and those erupting within the first 30 days are *neonatal teeth* (usually lower incisors). These are rare and often associated with syndromes or require extraction if they are mobile (risk of aspiration). * **12 months (D):** While some children experience "delayed dentition," 12 months is significantly past the average onset. Dentition is considered delayed only if no teeth have erupted by **13 months** of age. **3. NEET-PG High-Yield Clinical Pearls:** * **Sequence of Eruption:** Lower Central Incisors → Upper Central Incisors → Upper Lateral Incisors → Lower Lateral Incisors. * **Delayed Dentition:** The most common cause of delayed dentition is **idiopathic**; however, pathological causes include **Hypothyroidism, Rickets, and Down Syndrome.** * **Permanent Dentition:** Begins at **6 years** with the eruption of the **First Molar** (often called the 6-year molar). Note that the first permanent tooth is a molar, not an incisor, and it does not replace any primary tooth. * **Formula for number of teeth (6–24 months):** Age in months – 6. (e.g., at 12 months: 12 – 6 = 6 teeth).

Question 478: The behaviour therapeutic falls in the management of enuresis. What is the pharmacological drug of choice for this case?

A. Phenytoin
B. Diazepam
C. Imipramine (Correct Answer)
D. Alprazolam

Explanation: **Explanation:** **Enuresis** (bedwetting) is defined as involuntary voiding of urine at night in children aged 5 years or older. While behavioral modifications (e.g., fluid restriction, bladder training) and **enuresis alarms** (the most effective long-term therapy) are first-line treatments, pharmacological intervention is indicated when these fail. **Why Imipramine is correct:** **Imipramine**, a Tricyclic Antidepressant (TCA), is a classic pharmacological choice for nocturnal enuresis. It works through a multifactorial mechanism: 1. **Anticholinergic effect:** It increases bladder capacity by relaxing the detrusor muscle. 2. **Alpha-adrenergic stimulation:** It increases the tone of the internal urethral sphincter. 3. **Sleep architecture alteration:** It lightens the depth of sleep, allowing the child to wake up to the sensation of a full bladder. **Why other options are incorrect:** * **Phenytoin:** An antiepileptic drug used for seizures; it has no role in bladder control. * **Diazepam & Alprazolam:** These are Benzodiazepines. They act as sedatives and muscle relaxants. By deepening sleep or causing excessive sedation, they may actually worsen enuresis rather than treat it. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** While Imipramine is a traditional choice, **Desmopressin (DDAVP)**—an ADH analogue—is currently considered the first-line pharmacological agent due to a better safety profile. * **Imipramine Toxicity:** It has a narrow therapeutic index. Overdose can lead to life-threatening **cardiac arrhythmias** (QT prolongation) and seizures. * **Relapse Rate:** Pharmacological treatments have a high relapse rate once the drug is discontinued compared to alarm therapy. * **Rule of 5s:** Enuresis is diagnosed after age **5**; the dry interval for "Secondary Enuresis" is **6** months.

Question 479: Which of the following is NOT a guideline for immunization against infectious diseases?

A. Live vaccines are contraindicated in pregnant women.
B. Live vaccines should not be administered within 3 months of giving human immunoglobulin.
C. Inactivated vaccines should not be given if there has been a significant reaction to a previous dose.
D. Hay fever, sickle cell anemia, and tuberculosis are contraindications for vaccination. (Correct Answer)

Explanation: **Explanation:** The correct answer is **D**. In clinical practice, it is crucial to distinguish between true contraindications and **false contraindications**. Hay fever (allergic rhinitis), sickle cell anemia, and tuberculosis are not contraindications to immunization. In fact, children with chronic diseases like sickle cell anemia are at higher risk for infections (e.g., *S. pneumoniae*) and are prioritized for specific vaccines like Pneumococcal and Meningococcal vaccines. Similarly, stable tuberculosis is not a reason to withhold routine immunization. **Analysis of Incorrect Options:** * **Option A:** Live vaccines (e.g., MMR, Varicella) are generally contraindicated in pregnancy due to the theoretical risk of the attenuated virus crossing the placenta and affecting the fetus. * **Option B:** Passive immunization with human immunoglobulin can interfere with the immune response to live vaccines. A gap of at least 3 months is required to ensure the exogenous antibodies do not neutralize the vaccine virus before it can trigger an active immune response. * **Option C:** An anaphylactic or severe systemic reaction to a previous dose of any vaccine (inactivated or live) is an absolute contraindication to further doses of that specific vaccine. **High-Yield NEET-PG Pearls:** * **Absolute Contraindications:** Anaphylaxis to vaccine components (e.g., neomycin, egg protein) and severe immunodeficiency (for live vaccines). * **False Contraindications:** Mild acute illness (low-grade fever, diarrhea), malnutrition, breastfeeding, and family history of adverse events are **not** reasons to delay vaccination. * **HIV Exception:** BCG is contraindicated in symptomatic HIV, but **Measles/MMR** can be given if the child is not severely immunocompromised.

Question 480: A baby placed in the prone position is able to lift the head and upper chest on extended arms by what age?

A. 1 month
B. 3 months
C. 6 months (Correct Answer)
D. 9 months

Explanation: **Explanation:** The development of gross motor skills follows a **cephalocaudal (head-to-toe) progression**. The ability to lift the head and chest while prone is a key milestone in achieving postural control and preparing for crawling. * **Why 6 months is correct:** By 6 months, an infant has developed sufficient strength in the cervical and thoracic spinal extensors. When placed in a prone position, the baby can support their weight on **extended arms** (palms), lifting the head and the upper chest completely off the surface. This is often referred to as the "pivot prone" position or the precursor to crawling. **Analysis of Incorrect Options:** * **1 month:** At this age, a baby can only momentarily lift the chin off the bed while prone. The head typically lags when pulled to sit. * **3 months:** The infant can lift the head and the upper chest, but the weight is supported on the **forearms** (elbows), not extended arms. This is the "tummy time" milestone where the head is held at a 45-90 degree angle. * **9 months:** By this age, the infant has progressed far beyond this milestone; they are typically crawling, sitting steadily without support, and starting to pull themselves to a standing position. **High-Yield Clinical Pearls for NEET-PG:** * **4 months:** The head lag disappears when the infant is pulled to a sitting position. * **5 months:** The infant can roll from supine to prone (front to back usually occurs first at 4 months). * **Red Flag:** Failure to achieve head control by 4 months or inability to sit independently by 9 months warrants further developmental evaluation.

Practice by Chapter

Normal Growth Parameters

Practice Questions

Developmental Milestones

Practice Questions

Puberty and Adolescent Development

Practice Questions

Growth Disorders

Practice Questions

Failure to Thrive

Practice Questions

Developmental Screening and Assessment

Practice Questions

Developmental Delays

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Growth Charts and Monitoring

Practice Questions

Short Stature

Practice Questions

Tall Stature

Practice Questions

Precocious and Delayed Puberty

Practice Questions

Psychosocial Development

Practice Questions

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