Consider the following statements about hormones: 1. Insulin is a peptide hormone. 2. Thyroxine is an amino acid derivative. 3. Cortisol is a steroid hormone. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Erythroblastosis fetalis (hemolytic disease of the newborn) is primarily caused by Rh incompatibility. It occurs when an Rh-negative mother carries an Rh-positive fetus. During the first pregnancy, fetal Rh+ red blood cells may enter the mother's circulation, prompting her to produce anti-Rh antibodies. In subsequent pregnancies with an Rh+ fetus, these antibodies cross the placenta and destroy the fetal red blood cells, causing severe anemia and jaundice.

Explanation:
All are correct: proteins are polymers of amino acids joined by peptide bonds; hemoglobin is a protein that transports oxygen in blood.

Explanation:
The right atrium receives deoxygenated blood from the body via the superior and inferior vena cavae. It then passes to the right ventricle, which pumps it to the lungs for oxygenation. The left atrium receives oxygenated blood from the lungs via pulmonary veins, and the left ventricle pumps it to the body. Thus, the right atrium is the receiving chamber for systemic deoxygenated blood.