D.) A trophic level
This is your answer I hope it helps.
All cells are produced from other cells is one of the principle of the cell theory.
Option B
<u>Explanation</u>:
"Cell theory" states that basic unit of life has some unique features which are categorized into three main faiths which explains that:
- First, any organism which is alive is made with one (unicellular) or more (multicellular) cells.
- Second, any living entity is made up of at least a cell which makes the cell the unit of life.
- Third, any cell that exits in nature is only because of the previous cell from which it takes birth.
Answer:
Leukocytes are also called white blood cells. These cells have a nucleus, unlike red blood cells that lack a nucleus. Also unlike red blood cells, white blood cells do not contain hemoglobin, which means they're not involved in the transport of oxygen.
<span>Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentration—in the direction against some gradient or other obstructing factor (often a concentration gradient).</span>
Plant cell (chloroplasts)