Answer: intercalary meristem
Explanation: meristematic tissue at the base of the leaf blade is ben to the plant growth
Answer:
provide protection against pathogens
Explanation:
Answer: The diffusion of ions along the axoplasm is faster,in myelinated compare to unmyelinated,
Neurons are the structural and functioning units of nervous system.They are the vehicles for transmission of impulses as electrical signals from one part of the cells,and from one part of the body to another.
The basic structural components of a typical neuron are the cellbody, the axon, and the dendrites.
Based on structure neurons are classified as myelinated and unmyelinated.This is based on the the surrounding layer of myelin sheath around the axon. The myelin provides the insulating layer for the axon.And ensures fast movement of impluses.
In myelinated neurons the myelin sheath are interrupted at intervals by gaps along the length of the axon called Nodes of Ranvier. These gaps contains more Na-K channels for influx and out-flux of K and Na+ ions for transmission of impulses.
The cytoplasm of axon is called axoplasm,Since this is surrounded by myelin sheath which contains Na-K+ channels,The rate of diffusion of ions along these channels is faster for depolarization to take place than in unmyelinated neurons. Inaddtion as these ions diffusion increases,its jump faster at the nodes of Ranvier (saltatory conduction) to the next axoplasm which further speed up the rate of transmission.
Unmyeinated lacks myelin sheath,therefore the exchange and the rate of diffusion of ions along the axons is low.
Explnation:
Answer:
The secondary immune response is the immune response when the same antigen , memory cells that was encountered before is remembered and the immune system make antibodies to counter it.
Explanation:
There is a difference between the primary immune response and secondary immune response.
In the primary immune response occur when the immune system encountered an antigen for the first time which lead to the generation of memory cells and and the B cells with the T cells produce antibodies.
While the secondary immune response occur when the same antigen that was encountered the first time is encountered the second time and it lead to the stimulation of memory cells to produce more and high quantities of antibodies to fight foreign substances.
The dominant ones. Whatever has been gained through evolution in adaptation to their specific environment.
