The protolith may be a sedimentary rock, an igneous rock or another older metamorphic rock. Metamorphic rocks make up a large part of the Earth 's crust and are classified by texture and by chemical and mineral assemblage (metamorphic facies). They may be formed simply by being deep beneath the Earth's surface, subjected to high temperatures and the great pressure of the rock layers above it.
Onions and garlic belong to the allium family. The delicious foundation of may recipes, they also impart disease-fighting, health-promoting properties.. Think of your favourite savoury recipes. You would probably be hard-pressed to choose one that does not start by sauteing sautÃ©ing onions or, garlic or. both
plastids. Since onion bulbs are below ground they do not get the light necessary for chloroplast development. There are lots of web sites available that have information on this subject. Try a google search using the words chloroplasts and onions or onion chloroplasts. If you are interested in learning more about cells, onions are a good experimental organism. Onion root tips are great to study mitosis and meiosis and the thin membranous epidermis between the onion rings are perfect for observing plasmolysis.