The ozone layer is located in which layer of the atmosphere? MCQ with Answer and Explanation

Explanation:
O negative blood group lacks A and B antigens on RBCs and Rh antigen. Hence, it can be transfused to any person without causing agglutination, making it the universal donor. AB positive has both antigens and is the universal recipient. Blood grouping is based on ABO and Rh systems. O negative is crucial in emergency transfusions when blood type is unknown.

Explanation:
Diastole is the relaxation phase of the cardiac cycle, during which the ventricles fill with blood from the atria. Systole is the contraction phase, pumping blood out. Atrial contraction (atrial systole) contributes to ventricular filling. Ejection phase is part of ventricular systole when blood is ejected. Normal diastolic and systolic pressures are 80 and 120 mmHg respectively.

Explanation:
Mitochondria and chloroplasts contain circular DNA and 70S ribosomes, enabling them to transcribe and translate some proteins independently, though they rely on nuclear genes for most proteins. This partial autonomy supports the endosymbiotic origin hypothesis. The presence of their own genetic material and protein synthesis machinery qualifies them as semi-autonomous. Thus, both assertion and reason are correct, and the reason correctly explains the assertion.