C
Neurons and other components come together to form nerve tissue
The brain is formed of many different parts and types of tissues
The central nervous system runs through the body and consists of many parts
A human being has many different systems
Robin can have a ddt concentration of 444ppm while the ddt concentration of soil is 10 ppm. This happens due to biological magnification.
<u>Explanation:</u>
In biological magnification the concentration of toxic substances at successive trophic levels keeps increasing. Due to biomagnification, what starts out as a small concentration grows while moving to successive trophic levels. DDT is a pesticide which is used to kill pests that affect crops.
DDT used in farms gets deposited in the soil. From the soil it can reach various trophic levels. At each trophic level its concentration keeps increasing.
Robin is a bird that is a secondary consumer and thus belongs to the higher trophic level. Thus even if the DDT concentration is as low as 10ppm in the soil its concentration will keep increasing and can become a high value like 444ppm.
Mitochondria is the power house of the cell (also pay attention in class)
Mitochondria important for the cell that can't survive without it but blood cell is an exception. Blood is a tissue in animals so RBCs are animal cells and don't have mitochondria
