Answer:
B
Explanation:
It has membrane-bound organelles. Mitochondria and chloroplasts are structures found in the eukaryotic cells.
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.
The answer is; B
Sometimes winds carry the sand of the beaches causing erosion. The fences act as breakers of this wind erosion. As wind tries to carry the sand, they encounter the fence and 'break'. Therefore, the sand is deposited along the fence forming a sand dune. These dunes also form protection from storm surges.
Answer:
all of these are echinoderms
Irk look it up on the computer
