Which of the following is a high-yielding exotic breed of cattle used in dairy farming? MCQ with Answer and Explanation

Explanation:
Thyroxine is an animal hormone secreted by the thyroid gland, regulating metabolism. Auxin, gibberellin, cytokinin, abscisic acid, and ethylene are plant hormones (phytohormones). Plant hormones control growth, development, and responses to environment. Thyroxine contains iodine and affects basal metabolic rate. Thus, thyroxine is unrelated to plant physiology.

Explanation:
Fibrous root systems consist of a dense network of thin, branching roots originating from the stem base, typical of monocots like grasses. Taproot system has a main central root (dicots). Adventitious roots arise from stems or leaves, prop roots are supportive. Fibrous roots are effective in preventing soil erosion.

Explanation:
The humerus is the upper arm bone. The femur is the thigh bone. So C is incorrect.