General Physiology

Step 1: Understanding the question.
The question is asking about the hormone released during the foetal ejection reflex in humans and its origin.
Step 2: Historical context.
During childbirth, the foetal ejection reflex is a mechanism in which oxytocin is released from the maternal pituitary to induce uterine contractions and aid in the delivery of the baby.
Step 3: Analysis of the options.

• (A) oxytocin, foetal pituitary: Incorrect. Oxytocin is released from the maternal pituitary, not the foetal pituitary.
• (B) oxytocin, maternal pituitary: Correct. Oxytocin is released from the maternal pituitary during the foetal ejection reflex.
• (C) human chorionic gonadotropin, placenta: Incorrect. Human chorionic gonadotropin is produced by the placenta during early pregnancy, but it is not involved in the foetal ejection reflex.
• (D) progesterone, corpus luteum: Incorrect. Progesterone is involved in maintaining pregnancy, but it does not trigger the foetal ejection reflex.

Step 4: Conclusion.
The correct answer is (B) oxytocin, maternal pituitary, as this is the hormone and source involved in the foetal ejection reflex.
Final Answer: oxytocin, maternal pituitary.

Step 1: Identify the lymphoid organ.
The spleen is the lymphoid organ that acts as a large reservoir of erythrocytes (red blood cells). It is located on the left side of the abdomen and is involved in filtering the blood.
Step 2: Role of the spleen as a lymphoid organ.
As a lymphoid organ, the spleen plays a key role in immune function. It helps in the removal of old or damaged erythrocytes, and also stores platelets. It contains white blood cells that are involved in immune responses, such as fighting infections and filtering harmful microorganisms from the blood.
Step 3: Conclusion.
The spleen not only acts as a reservoir of erythrocytes but also plays an essential role in maintaining the body's immune system and overall blood health.

Step 1: Understanding the parts of a flower.
The figure shows the anatomy of a fruit. The thalamus is the part of the flower that connects the ovary, stem, and petals. The mesocarp refers to the middle layer of the fruit, while the endocarp is the innermost layer surrounding the seed.
Step 2: Analyzing the options.

• (A) P - Seed, Q - Thalamus, R - Mesocarp, S - Endocarp: Incorrect. The seed is typically surrounded by the endocarp, not the thalamus.
• (B) P - Thalamus, Q - Seed, R - Endocarp, S - Mesocarp: Incorrect. The thalamus is not the part inside the fruit.
• (C) P - Seed, Q - Thalamus, R - Endocarp, S - Mesocarp: Correct. The seed (P) is inside the endocarp (R), and the thalamus (Q) supports the fruit. The mesocarp (S) surrounds the seed.
• (D) P - Thalamus, Q - Seed, R - Mesocarp, S - Endocarp: Incorrect. The thalamus cannot be part of the fruit's internal layers.

Step 3: Conclusion.
The correct answer is (C) P - Seed, Q - Thalamus, R - Endocarp, S - Mesocarp.
Final Answer: (C) P - Seed, Q - Thalamus, R - Endocarp, S - Mesocarp.