Obsidian is an extrusive rock that is formed when magma from underneath the Earth's crust breaches and becomes lava. Once the lava starts cooling, it solidifies and elements are frozen, giving the rock its glassy appearance.
From the options given above, the correct option is D. A haploid cell is a cell that contains a single set of chromosomes only. A haploid cell can only undergo asexual reproduction. Asexual reproduction involves only one parent and the cell division usually occurs by mitosis. An organism that is reproducing asexually will transmit 50% of its gene to its offspring[s]. Thus, haploid cells reproduce asexually through mitosis only.
Answer: D. allopatric; breakdown
Explanation:
Allopatric speciation is a type of speciation whereby individuals of the same biological population becomes separated up to the extent that there will no longer be gene flow between them.
For many species, there are often regional differences in their genes, although most of the time this differences aren't noticeable in their outward appearance.
