In human pregnancy, which statement correctly describes the main function of the placenta tissue between mother and embryo?

Introduction / Context:

The placenta is a temporary organ that forms during pregnancy and plays a vital role in the growth and survival of the developing embryo and fetus. It connects the maternal and fetal blood supplies indirectly and allows exchange of materials between them. Exam questions commonly ask about the functions of the placenta, such as nutrient supply, waste removal, gas exchange, and hormone production. This question focuses on recognising that the placenta handles both nutrition and waste removal for the embryo, not just one of these tasks.

Given Data / Assumptions:

• The organ of interest is the placenta in humans.
• We must choose a statement that correctly summarises its main work with respect to the embryo.
• Options mention mechanical support, nutrition, waste removal, and hormone production in different combinations.
• We assume a basic understanding of maternal fetal exchange during pregnancy.

Concept / Approach:

The placenta functions as an interface between maternal and fetal blood. Through it, oxygen and nutrients from the mother pass into the fetal blood, while carbon dioxide and other metabolic wastes from the embryo are transferred to maternal blood for elimination. In addition, the placenta secretes hormones necessary for maintaining pregnancy. However, in simple exam statements, the most emphasised functions are providing nutrition and removing waste. Therefore, the statement that combines both of these correctly reflects the main role of placental tissue in supporting the embryo.

Step-by-Step Solution:

Step 1: Recall the core roles of the placenta: exchange of gases, supply of nutrients, and removal of wastes. Step 2: Identify that the embryo depends on placenta for both nutrition and waste elimination. Step 3: Examine each option and look for the one that states both functions together. Step 4: Notice that option B mentions both removing waste and providing nutrition. Step 5: Choose option B as it best summarises the main work of the placenta with respect to the embryo.

Verification / Alternative check:

Biology textbooks describe the placenta as performing functions similar to respiratory, digestive, and excretory systems for the fetus. Diagrams show maternal blood sinuses and fetal capillaries in close contact, with arrows illustrating flow of oxygen and nutrients in one direction and carbon dioxide and metabolic wastes in the other. This confirms that both nutrition and waste removal occur across the placental barrier. Though hormone production is also important, it is usually mentioned separately and not as the only function.

Why Other Options Are Wrong:

Option A, Support the embryo mechanically, is incomplete because the placenta primary role is not simply mechanical support; the uterus and surrounding tissues provide structural support. Option C, Provide nutrition to the embryo only, ignores the equally important role of removing waste products. Option D, Remove waste matter from the embryo only, again leaves out the essential supply of nutrients and oxygen. Option E, Produce hormones but not transport substances, is incorrect, because although placenta secretes hormones like human chorionic gonadotropin and progesterone, it also performs extensive transport of substances between mother and fetus.

Common Pitfalls:

Students sometimes latch onto one function they remember best, such as nutrition, and forget that waste removal is just as critical. Others may be distracted by hormone production and pick an option that emphasises it while ignoring the main exchange functions. To avoid these errors, learners should picture the placenta as a multipurpose interface that acts like lungs, intestine, and kidneys for the fetus, handling gas exchange, feeding, and excretion together.

Final Answer:

The main work of the placenta tissue is to Remove waste matter from the embryo and provide nutrition to the embryo.