The primary xylem in roots is: MCQ with Answer and Explanation

Explanation:
The limbic system is a complex set of structures in the medial temporal lobe, including the hippocampus, amygdala, and hypothalamus. It is often called the 'emotional brain' and is primarily responsible for processing emotions (fear, anger, pleasure), forming and retrieving memories, and regulating motivation and homeostatic drives (hunger, thirst). The medulla regulates heart rate, the cerebellum coordinates movement, and the occipital/temporal lobes process sensory information.

Explanation:
R.H. Whittaker's five kingdom classification places all prokaryotic organisms in Kingdom Monera and unicellular eukaryotes in Kingdom Protista. Fungi are a distinct kingdom characterized by heterotrophic nutrition, primarily saprophytic or parasitic, and possess chitinous cell walls. They are not photosynthetic autotrophs. Therefore, statements 1 and 2 are correct, while 3 is incorrect.

Explanation:
Glucagon is secreted by alpha cells of the islets of Langerhans when blood glucose is low. It acts on the liver to stimulate glycogenolysis (glycogen to glucose) and gluconeogenesis (synthesis of glucose from non-carbohydrates), thereby increasing blood glucose. Insulin, from beta cells, lowers blood glucose. Somatostatin inhibits both.