Answer:
The charges inside and outside of the neuron before receiving a stimulus are negative and positive, respectively, which corresponds to the transmembrane rest potential.
Explanation:
Neuron is the specialized cell of the nervous system in charge of transmitting electrical impulses. The generation of a nerve impulse in the form of an electric current is due to a change in the transmembrane potential.
<u>Outside the neuron cell, electrical charges are predominantly positive, and the ion with the highest concentration is sodium. In the intracellular space, a great quantity of proteins provide negative charge, and there is a predominance of potassium ions</u>. Under these conditions, the ionic channels are closed.
For this reason, a neuron at rest, before receiving a stimulus, presents positive charges on the outside and negative charges on the inside, and the membrane potential in this condition is estimated at a value of -65 mV.
Once a stimulus is produced, the ionic channels open and Na+ ions enter the cytoplasm, exchanging them for K+, which implies a change in the membrane potential which, on reaching the threshold, produces an action potential and the nerve impulse is produced.
Answer:
D.) If the homozygous tall plant (TT) crosses with a homozygous short plant (tt), then all the F1 plants become heterozygous tall plants (Tt).
Explanation:
Homozygous indicates that the alleles in the genotype are the same. Therefore, the genotype for homozygous tall plants is (TT) and the genotype for homozygous short plants is (tt).
After performing a cross, we know that all of the children will have the heterozygous genotype (Tt).
This maps says world old geography condition.first stage of Earth continent
Prophase, metaphase, anaphase, and telophase.
Answer:
The correct model is D.
Note: The first attachment below shows the different models. The second attachment shows the correct structural model of the water molecule.
Explanation:
A water molecule is composed of one atom of oxygen and two atoms of hydrogen.
A water molecule is polar, i.e. it contains positively and negatively opposite ends. The polar nature of the water molecule is due to strong electronegativity of oxygen which results in an uneven sharing of the bonding electrons between oxygen and hydrogen. The oxygen atom attracts the shared electrons more to itself, thereby, it acquires a partial negative charge, while the hydrogen atoms acquire a partial positive charge.
The bond angle between the oxygen and hydrogen atoms is approximately 105°. Therefore, from the first attachment below, the correct model for the water molecule is D.