Pollen grain, embryos, seed coatings, and megasporangium.
<span>Metalloids are metallic-looking brittle solids that are either semiconductors or exist in semiconducting forms, and have amphoteric or weakly acidic oxides. Typical nonmetals have a dull, colored or colorless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides.</span>
The correct option is this: PROTO ONCOGENES BECOMES ONCOGENES.
Proto oncogenes genes are those genes that regulate the process of normal cell division in the living system. These cells starts cell division when necessary and terminate the cell division when the necessary cells have been formed. When these genes lose the power to regulate cell division, the cells continue to divide indefinitely without stopping and this leads to a medical condition called cancer. At this stage, the proto oncogenes have been turned into oncogenes, which are genes that caused uncontrolled cell cycle divisions.
The answer is probably B because white blood cells are part of the immune system, so help to fight diseases. The circulatory system helps to move the white blood cell around the body. Also, pathogens are disease causing organisms, and as you can see, they all relate very well. Hope i helped, have a nice day.