The answer is D, white blood cells.
The main function of white blood cells is to defense the body from bacteria or other pathogens. There's 2 main kinds of white blood cells, lymphocytes and phagocytes. Lymphocytes mainly produce antibodies that can kill bacteria or any pathogens, and phagocytes can ingest the pathogens directly.
Therefore, since the white blood cells can protect our body, they're part of our immune system.
Answer: A gene that exhibits multiple phenotypic expression.
The concept would be crystallization. As magma cools inside or outside of the earth it crystallizes into an igneous rock. Intrusive (formed inside crust) igneous rocks are typically more course grained and contain many different noticeable minerals (for example, granite). Extrusive (formed outside) igneous rocks are typically more porous and are more fine grained then intrusive rocks (example, obsidian).
If you want a description of Bryophyte or how it looks like is that:
It is a small green plant that is flowerless and consists of Mosses and Liverworts. It can also be referred as Embrophytes.
Answer:
a stationary front moves when a cold front or warm front stops moving this happens when two masses of air are pushing against each other but neither is powerful enough to move the other winds blowing parallel to the front instead of perpendicular can help it stay in place.
