AIIMS 2019 Biology Plant Hormones MCQ Question

Cytokinins are plant hormones that promote cell division and shoot formation, making them essential for increasing shoot growth in callus cultures. They work by stimulating the growth of lateral buds and enhancing the development of shoots from undifferentiated tissue. In contrast, auxins (B) primarily promote root formation and cell elongation, gibberellins (C) are involved in stem elongation and seed germination, and abscisic acid (ABA) (D) typically functions in stress responses and inhibiting growth. Thus, while auxins, gibberellins, and ABA play important roles in plant development, they do not specifically enhance shoot growth in callus cultures like cytokinins do.