Consider statements about human brain: 1. The cerebrum controls voluntary actions. 2. The cerebellum maintains balance. 3. The medulla controls breathing. Which are correct? MCQ with Answer and Explanation

Explanation:
A plasmid used as a cloning vector in genetic engineering must have certain essential features: an Origin of Replication (ori) to ensure its replication within the host cell, a Selectable Marker (like an antibiotic resistance gene) to identify and eliminate non-transformants, and at least one unique Restriction Site (cloning site) for the insertion of the foreign DNA.

Explanation:
James Watson and Francis Crick, in 1953, proposed the double helix model of DNA based on X-ray diffraction data from Rosalind Franklin and Maurice Wilkins. Mendel discovered laws of heredity, Morgan linked genes to chromosomes, Beadle and Tatum proposed one gene-one enzyme, Hershey and Chase confirmed DNA as genetic material.

Explanation:
Reflex actions are rapid, involuntary responses to stimuli, primarily coordinated by the spinal cord without immediate brain involvement. The reflex arc includes receptor, sensory neuron, interneuron (in spinal cord), motor neuron, and effector. The brain is later informed. Examples: withdrawal of hand on touching a hot object. The medulla controls autonomic functions like breathing. The cerebrum handles conscious thought, cerebellum coordination.