(a) Myelinated and non-myelinated axons
(b) Dendrites and axons
(c) Rods and cones
(a) Myelinated and non-myelinated axons
| Features | Myelinated axons | Non-myelinated axons |
| Myelin sheath | Presence | Absence |
| Nodes of Ranvier | Presence | Absence |
| Location | grey matter of the brain, autonomous nervous system, spinal cord | Spinal cord, white matter of the brain, autonomous nervous system |
| Conduction of the nerve impulse | Node – node | Smooth |
| Speed of impulse-conduction | 50 x faster when compared to non-myelinated axon | Lower |
(b) Dendrites and axons
| Dendrites | Axons |
| Short processes | Long processes |
| Carry nerve impulse towards the cell body of the neuron | Carry nerve impulse away from the cell body to the neuron |
| Branched | Unbranched |
| Nissl’s granules – Presence of neuroplasm | Nissl’s granules – Absence of neuroplasm |
(c) Rods and cones
| Rods | Cones |
| Rods are sensitive to the dim light | Cones are sensitive to the bright light |
| Has rhodopsin pigment | Has iodopsin pigment |
| Does not involve in the colour vision | Important for the colour vision |
| No kinds | Kinds of cones– red, blue, green |