Answer: Option A. -> Below the hypothalamus
:
A
Pituitary gland is the major endocrine gland, a pea-sized body attached to the base of the brain just below the hypothalamus. It is important in controlling growth and development and the functioning of the other endocrine glands.

Answer: Option D. -> All of these
:
D
Like a camera, the human eye focuses light to produce sharp images. Light rays reflecting from distant objects are focused on the retina after they passed through the cornea, aqueous humor, the lens, and finally the vitreous humor.

Answer: Option B. -> 1. Receptor organs, 2. Sensory system, 3. Ear, 4. Eye, 5. 5
:
B
The most important structures to receive external stimulus are Receptor organs, and the system of these organs is called Sensory system.Two prominent sense organs areear and eye. Based on the sensations they receive, receptor organs systems are categorised into 5 types: Gustatory, Olfactory, Visual, Auditory and Tactile systems.

Answer: Option C. -> Vagus
:
C
Thevagus nerveis one of 12 cranial nerves. It is the longest of the cranial nerves, extending from the brainstem to the abdomen by way of multiple organs.The vagus nerve is two nerves that go through the brain stem and enter different parts of the body such as the heart and the stomach.

Answer: Option C. -> Temporal lobes
:
C
Thetemporal lobeis involved in primary auditory perception, such as hearing, and holds the primary auditory cortex.

Answer: Option C. -> Repolarization
:
C
The onset of the action potential in a polarized neuron triggers repolarisation.
The onset of anaction potential is marked by the opening of voltage-gated Na⁺ channels. The depolarization that occurs due to this, causes the neuron membrane to attain a voltage that triggers the opening of voltage-gated K⁺channels. Then K⁺ions rush out through this channels, reducing the positive charge inside the neuron, it causes repolarization of the neuronal membrane.

Answer: Option B. -> Neurotransmitter
:
B
Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a neuron and another cell. They are released by vesicles present in the pre-synaptic knob ofaxon terminals. Then they get released into synaptic cleft and bind to the receptors presenton the membrane of a post-synaptic membrane of either another nerve cell of a muscle cell.

Answer: Option B. -> Unidirectional
:
B
Nerve impulse alwaysenter and leave a neuronthrough the dendrites and axon endings respectively. This always ensures unidirectional impulse transmission.

Answer: Option B. -> Na+ ions move inside
:
B
Depolarization of a nerve cell membrane occurs during the passage of an action potential along the axon where the nerve is transmitting an impulse. During depolarization, the Voltage-gated Na⁺ channels open, and Na⁺ rush into the axon. Entry of sodium ions leads to depolarization (reversal of polarity) of the nerve membrane. This membrane depolarization causes the opening of voltage-gated K⁺channels, allowing K⁺ions to exit and repolarization of the membrane.

Answer: Option A. -> Middle of retina
:
A
Macula lutea is an oval yellowish area surrounding the fovea near the centre of the retina in the eye. This region of the retina is responsible for sharp and detailed vision, also called visual acuity. This region contains very high concentration of cone cells.