Nitrogen fixation is a process in which nitrogen (N2) in the Earth's atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or molecular dinitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds.
<em>Lets take a look at all the choices:</em>
A) Energy utilization
All organisms require energy to survive. That question is out for sure!
B) Complex Yet Organized
All living organisms are complex, and if they weren't organized, well, they wouldn't exist or they would have some serious problems!
C) Capable of Self-Reproduction
Simple: Not all organisms are able to reproduce asexually, for example, humans. We do not reproduce asexually. Therefore it is not a characteristic of <u>ALL</u> living organisms
D) Composed of Multiple Cells
No-brainer! All living organisms are composed of multiple cells!!!!!!!!!!!!
Therefore, the answer is C) Capable of Self-Reproduction
A. Cohesion is a property of water that describes the attraction due to hydrogen bonding between water molecules.
<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
</span>
cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
The statements of the old cell theory are:
1. All organisms are composed of cells
2. The cell is the basic unit of life
3. Cells are produced from existing cells
The modern cell theory's statements are:
1. The cell contains hereditary information which is passed to daughter cells
2. All cells are basically the same in composition and activity
3. All basic functions occur in cells
4. Cell activities depend on intracellular structures
As is visible from the statements, the old cell theory was not as detailed and lacked the understanding of the function, structure and behavior of cells that the current theory possesses. This difference has come about after years of research, through which scientists understood the functions of cells and elaborated on the theory's statements.