Answer:
He meant that the supporting cells form a insulating coat on the nerve fibre called myelin seath. The myelin Sheath act similar to the rubber coating of household wiring because it electrically insulates the nerve fibre and speeds of conduction of nerve impulse..
Explanation:
- The supporting cells of the nervous system are together called neuroglia or glial cells.
- Unlike neurons these cells can divide in the mature nervous system and do not conduct nerve impulse.
- Out of six types of glial cells, four are located in the central nervous system (CNS) and they are;astrocytes, oligodendrocytes, ependymal cells and microglia.
- The remaining two types are the part of Peripheral nervous system (PNS) and include Schwann cells and Sattelite cells.
- Among these , the oligodendrocytes of the CNS and Schwann cells of the PNS forms myelin sheath on the axons of the nerve cell that act similar to the rubber coating on the household wiring.
- The myelin sheath electrically insulates the axon of a neuron and increase the speed of conduction of nerve impulse.
Macromolecules provide structural support, a source of stored fuel, the ability to store and retrieve genetic information, and the ability to speed biochemical reactions , hope this helps :)
Answer:
Since genetically engineered (GE) crops were introduced in 1996, their use in the United States has grown rapidly, accounting for 80-90 percent of soybean, corn, and cotton acreage in 2009. To date, crops with traits that provide resistance to some herbicides and to specific insect pests have benefited adopting farmers by reducing crop losses to insect damage, by increasing flexibility in time management, and by facilitating the use of more environmentally friendly pesticides and tillage practices. However, excessive reliance on a single technology combined with a lack of diverse farming practices could undermine the economic and environmental gains from these GE crops. Other challenges could hinder the application of the technology to a broader spectrum of crops and uses.
Explanation:
Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.
The only job of the pulmonary artery is to carry deoxygenated blood from the heart to the lungs.
Hope this helps!
