Answer:
cell wall,vacoule,and plastids are not present
Yes, our distance from nature and our chronic immunological discontent could be related. Nature may be the cause of allergic problems.
<h3>What is an allergy?</h3>
Allergy is a common immune response produced by certain substances that alter the stability of the immune system.
Allergy may be caused by different materials present in nature that alter our immune system.
For example, pollen grains may cause allergic responses such as inflammation and thus produce chronic immunological problems.
Learn more about allergies here:
brainly.com/question/2681615
Answer:
Contagious is a method in which a bloodborne pathogen may be transmitted
Explanation:
Contagious are contacted as a result of transmission through blood contact, serum, sweat among others where diseases are said to be infectious
Answer: Option B) have mitochondria and chloroplasts.
Plant cells have mitochondria and chloroplasts.
Explanation:
Unlike animal cells, plants cells possess mitochondria and chloroplasts. Mitochondria serves as site for respiration giving off oxygen as by-product while chloroplasts are site of photosynthesis, where sugar molecules are formed from simple inorganic molecules like atmospheric carbon dioxide, water and sunlight trapped by chlorophyll.
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.
