Stimulus stimulate the sodium ion voltage gated channel to open in the axon. This allow many Na ion to enter the axon and causes depolarisation as the pd in the axon getting less negative charge (from -70mV to -50mV).
Neuron
Neuron can be defined as excitable
cell that usually carries, processes and transmit impulses or electrical
signals. Thus, they are known to be basic unit of the nervous system which
includes the spinal cord and brain. However, the signals between s neurons occur
via certain connections called synapses.
Answer:
1) pathway taken by water
water is absorbed from the soil, through the root hair cells and is transported by the xylem vessel up the stem to the leaf and/or flowers. From the leaf, some water is lost to the atmosphere as vapors escape out through the stoma present in the lower epidermal layer of the leaves.
2) water potential gradient
water potential refers to the concentration of water present. A gradient forms when there is a difference between the concentrations of water in two regions separated by a partially permeable membrane.
Hence, water moving down a water potential gradient means that it goes from a region of high water potential to a region of low water potential.
3) There are tiny openings on the lower side of the leaves called as stomata (plural: stoma) that allow for gaseous exchange to occur. These openings are controlled by guard cells which are open during the day and close during the night.
Hope that answers the question, have a great day!
