Answer:
When starfish were removed from their environment, the species richness of that area went down. This was because the starfish ate the mussels, and when the starfish were removed, the mussels became abundant and preyed on many of the other species.
This experiment showed that the starfish were a keystone species. A keystone species is a species that has a low biomass but a large impact on the community they are living in.
Answer:
The human eye is the prime organ of the body, which associates with the photons of light and allows one to see various things. The unique cells found in retina, which does activity of seeing are cones and rods cells. Rods help to see in dim light vision, while on the other hand, cone cells are unique in recognizing different colors.
These cells comprise photoreceptor proteins that help in trapping photons at particular wavelength. Mutation in the gene encrypting for these proteins results in permanent or temporary vision issues. The extremity of defects relies upon the degree to which mutation takes place.
The mutation in rod cells photoreceptor proteins leads to night blindness and retinitis pigmentosa. Retinitis pigmentosa refers to an inherited disorder that takes place because of early loss of rod cell, which destructs retina. On the other hand, night blindness does not mean complete blindness night, however, inadequate tendency to see in low light.
Identically, the mutation in the cone cell also results in vision issues, known as red color blindness and tritanopia. Tritanopia refers to a kind of color blindness, which originates because of insensitivity of blue receiving protein gene towards blue light. On the other hand, red color blindness refers to insensitivity of red receiving cone cells in captivating long-wavelength photons.
Answer: The correct answer is B) city hall:control center.
As per the question, model of cell looks like a city where different buildings correspond to different organelles ( membrane bound subcellular compartments like nucleus, golgi complex, vacuole, endoplasmic reticulum).
Nucleus is a specialized membrane bound compartment that possesses the genetic material ( DNA) of the Eukaryotes ( like plants and animals).
Nucleus controls all the essential activities of the cell by regulating the expression of gene ( segment of DNA corresponding to a particular protein).
Therefore, in the model of cell, city hall;control center represents the nucleus of the cell.
