Answer:
The correct answer would be B. semi-permeable.
Plasma membrane of any cell including red blood cell is semi-permeable in nature as it is made up of lipid bilayer.
It permits the passage of certain substances across the membrane while it blocks other substances.
Gases, small uncharged or non-polar substances such as oxygen, carbon dioxide, et cetera can easily pass through the cell membrane of a cell.
Large or charged molecules such as proteins, sodium ions, potassium ions et cetera can not pass through the cell membrane. They require carrier proteins to pass through the membrane.
To know where it rightfully belongs to. Variation of certain traits is caused by multiple factors of an individual of the same kind. Depending on their physical appearance, their environment and nature of survival.
Hope this might help.
Answer:
D.To promote open and profitable international trade
Answer:
I would say We don't have enough evidence or Cell theory is still changing.
Explanation:
There are so many cells in everything so it's almost impossible to know exactly what is going on. Theories about cells have been going on for over 500 years, and we still don't know exactly what is what.