The glands located besides the thyroid are the Parathyroid gland.
The density of a population of living organisms is usually measured in individuals on one square km. In here we have 50 earthworms on an area of 5 square meters, thus we have 10 earthworms on every square meter. In order to get to the result we need to see first how many square meters there are in one square km. One square km has one thousand meters of length and one thousand meters of width so:
1,000 x 1,000 = 1,000,000 km²
Since we established that we have 10 earthworms on every one square meter, we just need to multiply the number of square meters with the amount of earthworms on every square meter:
1,000,000 x 10 = 10,000,000
So we have a density of 10 million earthworms per square km.
Free-living flat worms = carnivores or scavengers
Have digestive cavity, mouth, pharynx
Parasitic Flatworms: = Feed on blood, tissue fluids, or pieces of cells from within a host
Answer:
The correct answer is C) There is a larger variety of MHC proteins that can be expressed on the cell surfaces of their immune cells, providing a wider opportunity to recognize and attack pathogens.
Explanation: