Karl Landsteiner classified human blood into four categories on the basis of proteins (antigens) found on the surface of the RBCs. Compatibility of blood groups must be checked during blood transfusion. Which of the following statements are incorrect ?

P. Blood group 'AB' is the universal donor as it does not contain any antibodies.

Q. Blood group 'AB' is the universal recipient as it contains both the antigens 'A' and 'B'.

R. Blood group 'O' is the universal recipient as it does not contain any antigens.

1. Only R
2. Only P and R
3. Only P and Q
4. Only Q and R

Geetika's mother has certain ailments of the heart. She is often very stressed and has anxiety. Sometimes, she experiences her heart beating too hard or too fast and occasionally even skipping a beat. Which of the following heart-related conditions explains her problem ?

1. Hypertension
2. Heart attack
3. Palpitations
4. Cardiac arrest

Assertion (A): None of the arteries carry deoxygenated blood in the human body.

Reason (R): Pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): The walls of the atria are thinner as compared to those of the ventricles.

Reason (R): The atria are the 'receiving chambers' and need to pump blood a short distance i.e. into the ventricles, while ventricles are the 'distributing chambers' and they must pump blood with much greater force to the lungs and the rest of the body.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.