The two ions are SODIUM AND CALCIUM IONS. Polarization refers to loss of polarization, that is, loss of the difference in charge between the inside and the outside of the plasma membrane of a muscle due to a change in permeability and migration of ion. When a heart muscle is depolarize, sodium ion and calcium ion channels open and they migrate into the cell from the outside.
Answer:
3. the absence of a cell wall in human cells
Explanation:
Animal cells do not have cell walls. Cell membranes separate the cytoplasm of the animal cells from the surroundings and maintain their interior. Plant cells have cellulosic cell walls. A cell wall surrounds the cell membrane of a plant cell. Cell walls serve to provide structural support and protect plant cells from pathogens. Cell walls also help keep excess water out of cells so they do not burst. Therefore, human cheek cells would not have cell walls while the onion cells would have cell walls made up of cellulose.
<span>The correct answer is the nucleus and the cell wall. Cell walls and Nucleus are only found in specific cells. Prokaryotic cells are cells that do not have definite nucleus in their cells, while Animal Cells do not have cell walls, yet the Plant Cells have cell walls.</span>
Humoral immunity<span> or humoural </span>immunity<span> is the aspect of </span>immunity<span> that is </span>mediated<span>by macromolecules found in extracellular fluids such as secreted </span>antibodies<span>, complement proteins, and certain antimicrobial peptides. Humoral </span>immunity<span> is so named because it involves substances found in the humors, or body fluids.</span>
Analyse
To examine something methodically to interpret or explain it.