Living Environment Regents Practice Test

How do nutrients transfer from the mother to the fetus?

1. Nutrients pass through breast milk.

2. Nutrients move across the placenta.

3. Nutrients are exclusively transferred through the umbilical cord.

4. Nutrients are absorbed through the skin.

The correct answer is: Nutrients move across the placenta.

Nutrients transfer from the mother to the fetus primarily through the placenta, which serves as a critical interface between maternal and fetal blood supplies. The placenta is a specialized organ that facilitates the exchange of nutrients, gases, and waste products without mixing the blood of the mother and the fetus. It allows essential nutrients like glucose, amino acids, and fatty acids to pass from the mother's bloodstream into the fetal circulation. This process occurs via diffusion and active transport mechanisms that ensure the fetus receives the necessary building blocks for growth and development throughout pregnancy. The efficiency of nutrient transfer is vital for fetal health, highlighting the importance of maternal nutrition during this period. The other options don't accurately describe the primary means by which nutrients are delivered to the fetus; for example, breast milk is only relevant post-birth, the umbilical cord mainly serves as a vessel for transporting blood rather than nutrients by itself, and skin absorption does not play a role in fetal nourishment.