NEETZoologyHuman Reproduction
A pregnant woman undergoes a routine ultrasound examination at exactly 12 weeks of gestation. Which of the following accurately describes the developmental status of the foetus at this specific stage?
Options
- AMost of the major organ systems are formed, including well-developed limbs and external genital organs.
- BThe foetus develops limbs and digits, but the major organ systems are not yet well-developed.
- CThe first movements of the foetus are observed along with the appearance of hair on the head.
- DThe body is covered with fine hair, the eyelids separate, and eyelashes are formed.
Correct answer
A. Most of the major organ systems are formed, including well-developed limbs and external genital organs.
Step-by-step solution
According to NCERT, the gestation period in humans is characterised by specific developmental milestones. At exactly 12 weeks (the end of the first trimester), most of the major organ systems are formed. For example, the limbs and external genital organs are well-developed. The development of limbs and digits occurs earlier, by the end of the second month ( 8 weeks). The first movements of the foetus and the appearance of hair on the head are observed during the fifth month (approx. 20 weeks). The body is covered w