Extrusive igneous rock is formed by the crystallization of magma release after volcanic eruption at the Earth surface. They are characterized by fine grained textures because of rapid cooling they do not form large crystals. Extrusive rocks with fine grained textures are called aphanitic rocks. The most common extrusive igneous rock is basalt. Other examples include rhyolite, andesite and obsidian. Extrusive igneous rocks erupt quickly and they form small crystals. Some of these rocks cools slowly that they form glass. These rocks includes andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria and tuff.
The common characteristic of extrusive igneous rock is the b. forms crystals
Rapid cooling of magma produces small crystal rocks.
Extrusive rock is one that forms when magma finds its way to the surface of the earth. The lava cools quite fast compared to intrusive rock that cools before it reaches the earth's surface. Lava that cools fast forms small crystals. Examples of extrusive rocks include; basalt, obsidian, and rhyolite. Intrusive rocks cool slowly and form large crystals.
B. Row x describes meiosis and row y describes mitosis
Explanation:
<em><u>Mitosis is the process in which a cell divides to yield two daughter cells with same number of chromosomes as the parent cell. </u></em>The process takes place in the somatic cells or the body cells. For example, a cell with 14 chromosomes divides to produce two cells with 14 chromosomes.
<em><u>Meiosis on the other hand is the process in which a cell divides into four daughter cells that have half the number of chromosomes as the parent cell.</u></em> The process takes place in the germ line cells where gametes are produced. For example a cell undergoes meiotic division to produce four cells each with 7 chromosomes.
