Answer:
A <u><em>receptor</em></u> is a protein that recognizes and responds to a signal.
Explanation:
A receptor is a protein molecule present on the cells on which the signalling molecules can bind and generate a physiological response. Some receptor molecules can also respond to Sun and light. Each type of cell has specific receptors molecules and hence can respond to specific signals. The receptor molecules hence tend to receive signals for a cell. Molecules such as hormones bind to the receptors.
C. Medusa. Everything else on the list is a part of another creature, medusa is the only cnidarian here!
Answer: Protozoa contaminate the water supply.
Some protozoa are parasites and cause diseases like malaria.
Protozoa have an important role in the food chain.
Protozoa are parasitic or free living single celled eukaryotic organisms. They are mostly found in water bodies.
Protozoa contaminate the water supply: Some of the protozoan species which are released from the human feces usually contaminate thee water, and causes waterborne infections in humans. Examples are Cryptosporium and Giardia. The infection occurs through drinking water or swallowing water from swimming pool.
Some protozoa are parasites and cause diseases like malaria: The Plasmodium is the genus belonging to the protozoan parasites. This malarial parasite is transmitted by female Anopheles mosquitoes to humans. The parasite multiply in the red blood cells causes symptoms like fever, anemia, flue, illness and may also cause coma and death.
Protozoa have an important role in the food chain: The protozoa species plays many roles in the food chain, they act as consumers, predators or prey, herbivores and decomposers. Their main function is to control the population of other species in the same habitat. They engulf small single celled bacteria, hence prevents excessive bacterial colonization act as predator. They also feed upon the algal species therefore, act as herbivores. They act as decomposers, as they feed upon the organic matter present in the bottom of the aquatic water body. They are the source of food for large worm and insect species.
Answer:
A. whether the glycoproteins or capsid proteins on its surface recognize those of the host cells.
Explanation:
Virus has different surface proteins that are recognized by the receptors present on its host cell. The range of a virus is determined by the recognition of these proteins by the host cell.
The interaction between the receptor on the host cell and surface proteins on the viral capsid is important for viral genome entry in the host cell and to determine the range of the host cells.
If the surface protein of the virus is not able to bind to the receptor on any cell then the virus can not infect the cell. For example, the HIV virus infects only those cell which have CD4 receptors. So the right answer is A.
Answer:
True
Explanation:
Since it's a passive way of transport, it is in favor of the concentration gradient and does not need to use ATP.
