The specific region where the exchange of gases occurs between air and blood in the lungs is the: MCQ with Answer and Explanation

Explanation:
The cohesion-tension theory (transpiration pull) is the primary mechanism for water ascent in tall trees. Transpiration creates negative pressure (tension) in leaves, water molecules cohere, and the column is pulled up. Root pressure and capillary action play minor roles. The cohesion of water is due to hydrogen bonds.

Explanation:
DNA (deoxyribonucleic acid) typically exists as a double-stranded helical molecule, with two complementary strands held together by hydrogen bonds between base pairs. RNA (ribonucleic acid) is generally single-stranded, allowing it to fold into complex three-dimensional shapes necessary for its various functions (mRNA, tRNA, rRNA). DNA contains the nitrogenous bases adenine, guanine, cytosine, and thymine; it does not contain uracil, which is found in RNA instead of thymine. Thus, statements 1 and 2 are correct.

Explanation:
Leprosy (Hansen's disease) is a chronic bacterial infection caused by Mycobacterium leprae, affecting skin, peripheral nerves, and mucous membranes. Tuberculosis is caused by M. tuberculosis. Diphtheria is Corynebacterium diphtheriae, plague is Yersinia pestis. Leprosy is curable with multidrug therapy.