Answer:
Galaxies rotate in their center with parts of galaxies that are far away from centre.
Explanation:
Galaxies move throughout the space. It rotates around its center with the portions of galaxy that are far from the center and moves relatively slowly from other objects near the center.
Because of the Big bang explosion because of which the Universe have expanded, galaxies are going away from other galaxies. The galaxy cluster also moves around the cluster center.
Answer: ALSO IF YOU DONT HAVE A ACTIVITY SLIDE ( It shows what your doing or makes you do a activity or it can make you do research) FOR THIS YOU MIGHT NOT UNDERSTAND THE ANSWER!
Explanation:
Look at the screenshot and hope this helps! Zoom in the screenshot if needed! ^^
A Nerve electrical impulse only travels in one direction. There are several reasons nerve impulses only travel in one direction. The most important is synaptic transport.
In order for a "nerve impulse" to pass from cell to cell, it must cross synaptic junctions. The nerve cells are lined up head to tail all the way down a nerve track, and are not connected, but have tiny gaps between them and the next cell. These tiny gaps are called synapses.
When you get a nerve firing, you have probably heard that it is an electrical impulse that carries the signal. This is true, but it is not electrical in the same way your wall outlet works. This is electrochemical energy. Neurotransmitters are molecules that fit like a lock and key into a specific receptor. The receptor is located on the next cell in the line. When the neurotransmitter hits the receptor on the next cell in line, it signals that cell to begin a firing as well.
This will continue all the way down the length of the nerve track. In a nutshell, a nerve firing results in a chain reaction down the nerve cell's axon, or stemlike section. Sodium (Na+) ions flow in, potassium (K+) ions flow out, and we get an electrochemical gradient flowing down the length of the cell. You can think of it as a line of gunpowder that someone lit, with the flame traveling down the length of it. Common electrical power is more like a hose full of water, and when you put pressure on one end, the water shoots out the other.
Therefore, nerve impulses cannot travel in the opposite direction, because nerve cells only have neurotransmitter storage vesicles going one way, and receptors in one place.
Answer:
c) receptor; control center; effector.
Explanation:
Homeostasis maintains the internal body conditions almost constant. It includes specific cells that sense any deviations of internal or external conditions from the normal range. These cells are called receptors. The sensory information from the receptors is delivered to the control center. The central nervous system mainly serves as a control system wherein sensory information from the receptors is processed. The control center commands muscles and/or glands to perform desired responses to restore the homeostasis. Here, muscles and glands serve as effectors.
For example, thermoreceptors sense the rise of body temperature and the brain (control center) commands sweat glands (effectors) to produce sweat.
