Answer:
Gated ion-channels
Explanation:
These ion channels are protein molecules that act as a passageway which span across the cell membrane allowing the movement of ions from one side of the membrane to the other. They possess the ability to open and close in response to either chemical or mechanical signals.They possess a fluidic pore, which becomes available to ions after a conformational change in the protein structure has been activated causing the ion channel to open. Based on the stimulus to which they respond, ion channels are divided into three groups: voltage-gated, ligand-gated and mechano-sensitive ion channels. Channels responding to electrical (voltage-dependent ion channels), mechanical, or chemical (ligand-gated ion channels) stimuli open and allow rapid ion movement into or out of the cell, and this movement creates an electrical signals.
Minerals may be defined as the combination of two or more elements of a substance.
<u>Five criteria that exhibits a particle to be minerals; </u>
- They are natural and not man-made.
- Inorganic i.e. not made by any organism.
- Minerals are solids, not liquid or gas.
- They have a definite chemical structure.
- The atoms in minerals are arranged systematically and are arranged in a repeated pattern.
Minerals are natural and we use it in our day to day life. Products like salt and even a pencil have minerals. Also, these minerals help the parts in the human body to grow faster and function properly.
Answer:
C. Go through a step called metaphase.
Explanation:
In plant and animal cells metaphase is a step they both share.
Answer:
Results in the evolution of the species: Directional selection
Results in new species: Disruptive selection
Favors traits at the two extremes: Disruptive selection
No increase in diversity: Directional selection
One extreme trait is favored: Directional selection
Diversity decreases: Stabilizing selection
Diversity increases: Disruptive selection
Explanation:
Directional selection which is also known as positive selection is known to be a mode of natural selection. In this type of selection, an extreme phenotype is favored over other phenotypes. This makes the allele frequency to move in the direction of that phenotype and this takes place over time.
Disruptive selection (known to be diversifying selection) talks about the certain changes in the population genetics whereby extreme values of a particular trait are favored over intermediate values. This results in new species.
While Stabilizing selection is a natural selection whereby there is a stabilization of the population mean on the particular value of a non-extreme trait. Here the diversity is decreases.
