Answer: depolarization; hyperpolarization
Explanation:
At resting potential (absence of stimulus), the cell membrane of a neuron is said to be polarized with a net negative charge within due to more potassium (K+) ions present than sodium (Na+) ions.
However, an impressed stimuli reverses the ions content as K+ ions flows out and quickly replaced by Na+ ions, resulting in a decrease in membrane potential and a more positive cell membrane. Thus, depolarization occurs.
An increase in the membrane potential (so that it becomes more negative) is called hyperpolarization.
I think the hydra lacks the specialized cells for touch and chemical detection. On the other hand earthworms have touch, light, vibration and chemical receptors along the entire body surface. Both of them are invertebrates (those animals without a backbone), they include insects, worms, jelly fish, spiders among other animals.
Answer:
Option C. A person inherits chromosomes from just one parent.
Explanation:
Genetic disorders or diseases that are caused by errors that occur during meiosis is called down syndrome. It is also known as trisomy 21. In this disease the person inherits one extra pair of chromosomes from one of the parent i. e. Father or mother.
Some micronutrients, such as vitamins e and c, can function as antioxidants in that they are able to neutralize free radicals. Radical are highly unstable molecules produced in our body when we are exposed to toxins. <span>Vitamins C and E, carotenoids (including </span>beta-carotene<span>), and the mineral </span>selenium<span> are all powerful antioxidants found in food.</span>
Hydrogen is similar to electricity. Although an electric vehicle, for an example, doesn't create any tail pipe emissions from the vehicle, that may not be the case where the electricity was made. If the electricity was made from an old, smoking, worn out gasoline powered generator in order to charge the electric vehicle, the total pollution created would be much more than that made by a regular gasoline car. However, if the electricity is made by an environmentally friendly renewable source, such as solar or wind, then the total pollution created in powering the electric vehicle would be much less, perhaps even zero.
<span>Hydrogen can be made from electricity or petroleum. If made from petroleum it wouldn't be much different than gasoline because the rest of the petroleum would have to be used somewhere. If the hydrogen is made from electricity then the question again is where is the electricity being made. </span>
<span>Your question is also a good one because it highlights the "high use" of renewable energy. The production and use of hydrogen in less efficient than running just off of electricity. So you'd have to produce a whole lot more electricity to make hydrogen to drive a car a certain distance than to charge a battery-electric car and drive the same distanc</span>
