Question
Question: Rods and cones of retina are modified A) Bipolar neurons B) Unipolar neurons C) Multipolar neu...
Rods and cones of retina are modified
A) Bipolar neurons
B) Unipolar neurons
C) Multipolar neurons
D) Hairs
Solution
Rod and cones are photoreceptor cells present in the eye. They contain photosensitive pigments. The pigments present in rods are Rhodopsin and that in cones are photopsins. They function in low-light and day- light vision.
Complete Answer:
Rod and cones are the photoreceptor neuroepithelial cells present in the retina of the eye. Rods help in low light vision whereas cones are active at higher light and aid in colour vision.
Structure of Rods and Cones-
They are found in the outermost layer of the retina. They share a similar basic structure.The axon terminal releases a neurotransmitter called glutamate to dendrite. The cell body or soma contains cell organelles. The inner segment contains numerous mitochondria. The rods and cones are bipolar in nature due to single dendrite and axon.
Unipolar neurons- These are the neurons that have only one neurite attached to it. Example- Neuron of the invertebrates.
Multipolar neurons- these neurons have a single axon but many dendrites. Example- purkinje cells.
Additional information The nerve transmission takes place by the help of axons and dendrites. At the junction between the axon of one neuron and dendrite of another is called the synapse secret neurotransmitter which helps in transmitting impulses.
The correct answer is (A). Rods and cones are bipolar.
Note: A bipolar neuron has two extensions- one dendrite and other axon. They are specialised sensory neurons for the transmission of senses like smell, sight, taste, hear, touch, and balance.