Growth and Development — MCQs

Growth and Development Indian Medical PG Practice Questions and MCQs

Question 361: What is the average number of words a child can develop by 18 months of age?

A. 3 words
B. 6 words
C. 8 words
D. 10 words (Correct Answer)

Explanation: **Explanation:** The development of expressive language is a critical milestone in pediatric growth. By **18 months of age**, a child typically has a vocabulary of approximately **10 words**. This stage marks the transition from single-word utterances to the beginning of word combinations. * **Why Option D is correct:** At 18 months, the "word spurt" begins. While there is individual variation, standard developmental charts (such as Nelson’s Pediatrics) define the average vocabulary at this age as 10 words. The child can also point to common objects and follow simple one-step commands. * **Why Options A, B, and C are incorrect:** * **3 words:** This is the milestone for a **12-month-old** (1 year). At this stage, a child usually says "Mama/Dada" specifically plus one other word. * **6-8 words:** These are intermediate stages between 12 and 18 months. By 15 months, a child typically uses 4–6 words. **Clinical Pearls for NEET-PG:** * **12 months:** Says 1–3 words with meaning. * **18 months:** Says 10 words; identifies one or more body parts. * **24 months (2 years):** Vocabulary of **50+ words** and starts using **2-word phrases** ("Telegraphic speech"). * **3 years:** Uses **3-word sentences** and gives their full name/gender. * **Red Flag:** If a child does not speak any single words by 15 months or 2-word phrases by 24 months, a formal hearing and developmental assessment are mandatory.

Question 362: Which of the following maternal disorders can lead to microcephaly in a baby?

A. Systemic Lupus Erythematosus (SLE)
B. Hepatitis A
C. Phenylketonuria (Correct Answer)
D. All of the above

Explanation: **Explanation:** The correct answer is **Phenylketonuria (PKU)**. This question tests your knowledge of **Maternal PKU Syndrome**, a critical concept in teratology and metabolic pediatrics. **1. Why Phenylketonuria is correct:** When a mother with PKU does not maintain a strict low-phenylalanine diet during pregnancy, high levels of phenylalanine cross the placenta. Phenylalanine acts as a potent **teratogen** to the developing fetal brain. This results in **Maternal PKU Syndrome**, characterized by a triad of: * **Microcephaly** (the most common finding, seen in >90% of cases) * Congenital Heart Disease (typically TOF or VSD) * Intellectual Disability and Growth Retardation **2. Why the other options are incorrect:** * **Systemic Lupus Erythematosus (SLE):** Maternal SLE is classically associated with **Congenital Heart Block** (permanent) and neonatal lupus (transient rashes/thrombocytopenia) due to the transplacental passage of anti-Ro (SS-A) and anti-La (SS-B) antibodies. It does not typically cause microcephaly. * **Hepatitis A:** This is an enterically transmitted virus that causes acute hepatitis in the mother but is not known to be teratogenic or cause congenital malformations like microcephaly. **3. High-Yield Clinical Pearls for NEET-PG:** * **Microcephaly Definition:** Head circumference <3 standard deviations (SD) below the mean for age and sex. * **Other Maternal Causes of Microcephaly:** Fetal Alcohol Syndrome (most common preventable cause), TORCH infections (especially CMV and Zika), and poorly controlled maternal Diabetes Mellitus (though more associated with macrosomia and sacral agenesis). * **Management:** To prevent Maternal PKU Syndrome, the mother must maintain phenylalanine levels between **2–6 mg/dL** prior to conception and throughout pregnancy.

Question 363: Which is not a feature of Edwards' syndrome?

A. Mental retardation
B. Stunting of growth
C. Hypotonia (Correct Answer)
D. Congenital heart disease

Explanation: **Explanation:** **Edwards’ Syndrome (Trisomy 18)** is the second most common autosomal trisomy among live births. The hallmark of this condition is **marked Hypertonia (spasticity)**, rather than hypotonia. 1. **Why Hypotonia is the correct answer:** Infants with Edwards’ syndrome typically present with significant **hypertonia** and rigid muscle tone, often accompanied by a characteristic "clenched fist" (index finger overlapping the third, and fifth finger overlapping the fourth). In contrast, Trisomy 21 (Down syndrome) is the classic trisomy associated with marked hypotonia. 2. **Analysis of Incorrect Options:** * **Mental Retardation (Intellectual Disability):** This is a universal feature of all viable autosomal trisomies (13, 18, and 21). Severe developmental delay is always present in Edwards’ syndrome. * **Stunting of Growth:** Intrauterine growth restriction (IUGR) and postnatal failure to thrive are cardinal features. These infants are typically small for gestational age. * **Congenital Heart Disease (CHD):** Over 90% of affected infants have CHD. The most common lesions are Ventricular Septal Defect (VSD), Atrial Septal Defect (ASD), and Patent Ductus Arteriosus (PDA). **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Edwards (18):** **E**lection age is **18**. Features include **E**longated skull (prominent occiput), **E**ars (low-set/malformed), and **E**xaggerated tone (Hypertonia). * **Rocker-bottom feet:** Shared with Patau syndrome (Trisomy 13). * **Micrognathia:** Small jaw is a very common finding. * **Prognosis:** Extremely poor; most succumb to central apnea or heart failure within the first year of life.

Question 364: At what milestone age of development is the Moro reflex typically absent?

A. 3 months (Correct Answer)
B. 5 months
C. 6 months
D. 7 months

Explanation: **Explanation:** The **Moro reflex** is a primitive, symmetrical neonatal reflex integrated at the spinal cord/brainstem level. It is elicited by a sudden change in head position or a loud noise, resulting in a two-phase response: abduction and extension of the arms (with finger splaying), followed by adduction and flexion (the "embrace" posture). **Why 3 months is correct:** The Moro reflex is present at birth and typically begins to fade by the 3rd month, becoming **completely absent by 3–4 months of age**. Its disappearance signifies the maturation of the central nervous system, specifically the transition from subcortical to cortical control of motor functions. **Analysis of Incorrect Options:** * **5 months:** By this age, the Moro reflex should have been absent for several weeks. Persistence beyond 4–5 months is a "red flag" for delayed neurological maturation or cerebral palsy. * **6 months:** At 6 months, infants are developing voluntary motor skills like sitting with support. Primitive reflexes like the Moro must be integrated by this time to allow for the development of protective equilibrium reactions (like the Parachute reflex). * **7 months:** This is significantly delayed. Persistence of primitive reflexes at 7 months is strongly associated with upper motor neuron lesions. **High-Yield Clinical Pearls for NEET-PG:** * **Asymmetrical Moro:** Suggests focal neurological or skeletal injury, such as **Erb’s palsy** (C5-C6) or a **fractured clavicle**. * **Absent Moro at birth:** Indicates a significant CNS depression, hypoxia, or severe motor weakness. * **Persistence:** If the reflex lasts beyond 6 months, it is a highly sensitive indicator of **Cerebral Palsy**. * **Sequence of disappearance:** Palmar grasp (2-3 months) → Moro (3-4 months) → Rooting (3-4 months) → Plantar grasp (9-12 months).

Question 365: What is the upper segment to lower segment ratio at 2 years of age in a normal child?

A. 1.08:1
B. 1.05:1 (Correct Answer)
C. 1.25:1
D. 1.12:1

Explanation: The **Upper Segment (US) to Lower Segment (LS) ratio** is a critical anthropometric measure used to assess skeletal proportions and detect conditions like skeletal dysplasias or precocious puberty. ### **Explanation of the Correct Answer** At birth, the limbs are relatively short compared to the trunk, resulting in a high US:LS ratio of approximately **1.7:1**. As the child grows, the lower limbs grow more rapidly than the spine, causing the ratio to decrease progressively. * **At 2 years of age:** The ratio typically reaches **1.05:1**. * **At 7–10 years of age:** The ratio reaches **1:1** (the symphysis pubis becomes the midpoint of the body). ### **Analysis of Incorrect Options** * **A. 1.08:1:** This value is closer to the ratio observed around 18 months of age. While close, 1.05:1 is the standard textbook value for 2 years. * **C. 1.25:1:** This ratio is characteristic of a child around **1 year** of age. * **D. 1.12:1:** This value is typically seen between 12 and 18 months as the ratio transitions from 1.2 to 1.05. ### **NEET-PG High-Yield Pearls** * **Measurement Technique:** The Lower Segment is measured from the top of the pubic symphysis to the floor; the Upper Segment is calculated by subtracting the LS from the total height. * **Increased US:LS Ratio (Short Limbs):** Seen in **Achondroplasia**, **Hypothyroidism** (cretinism), and **Rickets**. * **Decreased US:LS Ratio (Long Limbs):** Seen in **Marfan Syndrome** and **Homocystinuria**. * **Summary Timeline:** * Birth: 1.7:1 * 1 Year: 1.2:1 * **2 Years: 1.05:1** * 7–10 Years: 1:1 * Adult: 0.9:1

Question 366: In which type of osteogenesis imperfecta do 90% of newborns die before 4 weeks of age?

A. Type I
B. Type II (Correct Answer)
C. Type III
D. Type IV

Explanation: **Explanation:** **Osteogenesis Imperfecta (OI)** is a group of genetic disorders primarily caused by mutations in the **COL1A1 and COL1A2** genes, leading to defective synthesis of Type I collagen. * **Why Type II is the correct answer:** Type II OI is the **most severe and lethal form** (Perinatal Lethal Type). It is characterized by extreme bone fragility, multiple in-utero fractures, and a "crumpled" appearance of long bones on X-ray. Most newborns (90%) die within the first few weeks of life due to **pulmonary hypoplasia** and respiratory failure resulting from a small, deformed thoracic cage. **Analysis of Incorrect Options:** * **Type I:** This is the most common and **mildest form**. It presents with blue sclerae and increased fracture risk after birth, but life expectancy is generally normal. * **Type III:** Known as the **Progressive Deforming** type. While severe, it is not typically lethal in the neonatal period. Patients survive but suffer from significant skeletal deformities and short stature. * **Type IV:** This is a moderate form with normal sclerae. It is intermediate in severity between Type I and Type III. **High-Yield Clinical Pearls for NEET-PG:** * **Sillence Classification:** The standard system used to categorize OI (Types I-IV). * **Blue Sclera:** Most prominent in Type I due to the thinning of collagen allowing the underlying choroidal veins to show through. * **Dentinogenesis Imperfecta:** Often associated with OI (opalescent teeth). * **Radiology:** Look for "Wormian bones" in the skull and "popcorn calcifications" near the growth plates in later stages. * **Treatment:** Bisphosphonates (e.g., Pamidronate) are the mainstay to increase bone mineral density.

Question 367: Primary dentition is complete by what age?

A. 1.5 years
B. 2.5 years (Correct Answer)
C. 3.5 years
D. 4.5 years

Explanation: **Explanation:** The primary (deciduous) dentition consists of **20 teeth** (10 per jaw). The process of eruption typically begins at 6 months of age and follows a predictable sequence. **Why 2.5 years is correct:** The completion of primary dentition occurs when the **second molars** erupt. While there is individual variation, the second molars typically appear between 20 to 30 months of age. Therefore, by **2.5 years (30 months)**, all 20 primary teeth are usually present in the oral cavity. **Analysis of Incorrect Options:** * **A. 1.5 years:** At this stage, a child typically has about 12–16 teeth (incisors and first molars). The second molars have not yet erupted. * **C. 3.5 years & D. 4.5 years:** These ages are well beyond the typical completion of primary dentition. By this time, the child is in a "stable" primary dentition phase, waiting for the eruption of the first permanent molar (6-year molar). **High-Yield Clinical Pearls for NEET-PG:** * **Sequence of Eruption:** Lower Central Incisor (1st) → Upper Central Incisor → Upper Lateral Incisor → Lower Lateral Incisor → First Molars → Canines → Second Molars. * **Rule of Four:** A rough guide for the number of teeth is **(Age in months – 6)**. For example, at 12 months: 12 – 6 = 6 teeth. * **Delayed Dentition:** Defined if no teeth have erupted by **13 months** of age. Most common cause is idiopathic, but must rule out Hypothyroidism, Rickets, and Down Syndrome. * **First Permanent Tooth:** The **Lower First Molar** (6 years), which erupts behind the primary second molar (it does not replace a primary tooth).

Question 368: What is the first sign of puberty in females?

A. Pubarche
B. Thelarche (Correct Answer)
C. Menarche
D. Increase in height

Explanation: **Explanation:** The correct answer is **Thelarche** (Option B). In females, the onset of puberty is marked by the activation of the hypothalamic-pituitary-gonadal (HPG) axis. The first clinical sign is **thelarche**, which refers to the development of breast buds. This typically occurs between the ages of 8 and 13 years and is driven by rising levels of estrogen. **Analysis of Options:** * **Thelarche (Correct):** It is the physiological starting point of female puberty. It usually precedes pubarche by about 6 months. * **Pubarche (A):** This refers to the appearance of pubic hair, driven by adrenal androgens (adrenarche). While it often follows thelarche, it is not the first sign. * **Menarche (C):** This is the onset of menstruation. It is a late event in puberty, occurring approximately 2–2.5 years after thelarche (typically at Tanner Stage 4). * **Increase in height (D):** While a growth spurt is a hallmark of puberty, the peak height velocity in girls usually occurs in Tanner Stage 2 or 3, shortly after thelarche, but it is not the *first* clinical sign. **High-Yield Clinical Pearls for NEET-PG:** * **Sequence of Puberty in Girls:** Thelarche → Pubarche → Peak Height Velocity → Menarche (Mnemonic: **T**all **P**eople **G**et **M**oney). * **Precocious Puberty:** Defined as the appearance of secondary sexual characteristics before age 8 in girls and age 9 in boys. * **Delayed Puberty:** Absence of thelarche by age 13 in girls. * **First sign in males:** Testicular enlargement (volume ≥ 4 ml), occurring due to testosterone.

Question 369: A woman whose previous child had Down syndrome (karyotype showed nondisjunction) comes for preconceptional counseling. What is the chance of Down syndrome in a subsequent pregnancy?

A. 1% (Correct Answer)
B. 5%
C. 10%
D. 25%

Explanation: ### Explanation **1. Why the Correct Answer is Right (Option A: 1%)** Down syndrome (Trisomy 21) most commonly occurs due to **meiotic nondisjunction** (95% of cases), which is typically a sporadic event. However, once a woman has had a child with Trisomy 21 due to nondisjunction, her risk of having another affected child is slightly higher than the age-matched general population risk. In clinical practice, this recurrence risk is estimated to be approximately **1%** (or the age-related risk, whichever is higher). This increase is attributed to potential germline mosaicism or genetic predisposition to nondisjunction. **2. Analysis of Incorrect Options** * **Option B (5%):** This is incorrect for nondisjunction. A 5% risk is more characteristic of a mother who is a carrier of a **Robertsonian translocation (14;21)**, where the recurrence risk is roughly 10-15% (though theoretically 33%). * **Option C (10%):** This is the approximate recurrence risk if the **father** is a carrier of a Robertsonian translocation (14;21). * **Option D (25%):** This risk does not correspond to standard Down syndrome inheritance patterns. It is more typical of autosomal recessive conditions. **3. NEET-PG High-Yield Pearls** * **Most common cause:** Meiotic nondisjunction (95%), mostly occurring during Maternal Meiosis I. * **Translocation:** Accounts for ~3-4% of cases. If a parent carries a **21;21 balanced translocation**, the recurrence risk is **100%**. * **Mosaicism:** Accounts for ~1-2% of cases; usually results in a milder phenotype. * **Screening:** The most sensitive first-trimester screen is the **Combined Test** (Nuchal translucency + PAPP-A + free β-hCG), which has a ~90% detection rate. * **Quadruple Test:** Performed between 15-20 weeks; shows **Low AFP, Low Estriol, High hCG, and High Inhibin A** (Mnemonic: **HI**gh = **H**CG and **I**nhibin).

Question 370: At what age does the first molar tooth typically appear?

A. 6-7 months
B. 8-9 months
C. 10-11 months
D. 12-13 months (Correct Answer)

Explanation: **Explanation:** The eruption of primary (deciduous) teeth follows a predictable chronological sequence in pediatric development. The **first molar** typically erupts between **12 and 16 months** of age (average 12–13 months). This marks a significant transition in the child's dietary capabilities, moving from soft foods to more complex textures. **Analysis of Options:** * **A. 6–7 months:** This is the typical age for the eruption of the **lower central incisors**, which are usually the first teeth to appear. * **B. 8–9 months:** This period usually sees the eruption of the **upper central and lateral incisors**. * **C. 10–11 months:** At this stage, the **lower lateral incisors** typically emerge. * **D. 12–13 months (Correct):** This aligns with the standard developmental milestone for the **first deciduous molar**. **High-Yield Clinical Pearls for NEET-PG:** * **Sequence of Eruption:** Central Incisor → Lateral Incisor → **First Molar** → Canine → Second Molar. (Note: The first molar erupts *before* the canine). * **Rule of 6s:** The first *permanent* tooth to erupt is the **first permanent molar** at **6 years** of age. * **Delayed Dentition:** Dentition is considered delayed if no teeth have erupted by **13 months**. The most common cause of delayed dentition is idiopathic, but it is also associated with conditions like hypothyroidism, hypoparathyroidism, and Down syndrome. * **Teething Formula:** For children under 2 years, the number of teeth can be estimated as: **Age (in months) – 6**.

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

Practice Questions

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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