The hormone that stimulates uterine contractions during childbirth is: MCQ with Answer and Explanation

Explanation:
Tissue culture (micropropagation) involves growing plant cells/tissues on a sterile nutrient medium to regenerate whole plants, producing clones. Hybridization is crossing varieties, cross-pollination is natural or artificial pollination, selective breeding chooses parents.

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:
The aorta receives blood directly from the left ventricle under high pressure (systolic ~120 mmHg). Pressure decreases as blood moves through arteries, capillaries, and veins. Vena cava pressure is near zero.