Answer:
A) A decrease in Na+ permeability, and an increase in K+ permeability.
Explanation:
When the potential action reaches a peak of about +40 mv Na+ channels are open and a high number of Na+ ions are entering the inside of the cell. Shortly after this happens the K+ channels will start to open their gates increasing the cell K+ permeability while the Na+ channels will start to close their gates, so the Na+ permeability will decrease. This happens in order to valance the positive charge on the inside of the cell. Normally the inside has a negative charge while the outside has a positive one, as the inside is more positive due to the increase in Na+ permeability at the beginning of the potential action, K+ cations (which are in abundance in the cell) will have to go out through the K+ channels so as to restore the charge valance, that means that there is an increase in K+ permeability.
Isotonic solution.
Since it has the same salt concentration as the cell the solution is neither hypotonic or hypertonic.
<span>A substance that is made of atoms of more than one type bound together is called a <span><u>compound</u>.
</span>A compound is a</span><span> substance consisting of atoms or ions of two or more different elements in definite proportions joined by chemical bonds into a molecule. </span><span>
</span>
These are all part of the head or skull. The cavities of the
skull surround and protect the brain and sensory organs. There are five kinds
of cavities of the skull which are:
nasal cavity (paranasal sinuses is included here) - The
nasal septum split the respiratory system into two lateral halves, the nasal
cavity is also part of the respiratory system.
<span>cranial cavity - The large cranial cavity is split
into a posterior cranial fossa and an anterior cranial
fossa, a middle cranial fossa. Its function is to support the
brain.</span>
<span>
</span>
oral cavity - The oral, or buccal, cavity (commonly called
the mouth) is a cavity of the head rather than a cavity of the skull because of
its fleshy and muscular floor.
orbital cavity - supports and defends an eyeball and its linked
muscle, vessels, and nerves.
<span>middle ear cavity - From outer to inner, three small bones-malleus,
incus, and stapes are situated within the middle-ear cavities in the
petrous part of the temporal bones.</span>
The daughter cells produced from Meiosis are genetically different from each other due to the process of Crossing Over in the stage of Prophase I.
In Mitosis, there is no Crossing Over involved, since it is intended to help the body in growth and repair, not in reproduction.
Genetic Variation is important for reproduction so that not all offspring look exactly like each other or so that they do not look exactly like their parents.
