There are various ways that geologists use for identification of minerals. These methods or tests are very simple to perform and can quickly help in the accurate identification of minerals. We will discuss here only three of them.
1) Hardness:
It is the property of a mineral that resists its scratching. It has something to do with the chemical bonding between atoms of a mineral. The stronger that bonding is, the difficult it is for you to scratch the mineral. Although presence of impurities can effect the right diagnosis of the mineral but still hardiness is a very good criteria to identify a mineral. For example, lead has very low hardness due to which we can write through it on paper, however a steal nib would never let us write because it has good hardness and it cannot be scratched easily. Please see the attached image, it shows hardness values of different minerals that give unique identification to them.
2)Streak:
It is the test in which mineral is scraped with a porcelain piece. This streaking can help in the diagnosis of the mineral in powdered form. For example, when chromite is streaked it gives choclate brown streaks and it is the color very different from all other minerals and it can be quickly identified.
3) Physical properties:
There are some ways of identifying a mineral by just looking at them, however some experts are better at it then some one who has zero experience. This is because minerals have some characteristics like color, luster (that can be metallic or non metallic) and taste or smell. For example, sulfur has a specific smell and it is quickly identified with it. Chalcanthite has a specific taste and it can be quickly identified with it.
Hope it helps!
The process of sexual reproduction involves two parents, each contributing one gamete. Gametes are produced
by a process called meiosis, which starts by the duplication of the
chromosomes, followed by two rounds of cell divisions and halving of the
chromosome number. Gametes have half the chromosome number of other
adult
cells of an organism.
A key feature of meiosis is the exchange of chromosome pieces which occurs in the first division of this process, called recombination or
crossing over. Recombination is a very important source of genetic
variation between individuals of sexually reproducing species, and the
driving force for the process of natural selection.
During a
head injury or a trauma, the brain can limit the spread of the damage by
forming a glial scar which seals off the damaged region from the rest of the
important parts. During this process, the glial cells are particularly
important. In specific, the glial cells Astrocytes will be the most abundant in
this process since they produce glucose and other essential nutrients which help
support the viability of the surviving cells. In addition, the astrocytes is responsible in maintaining the
brain environment stability (homeostasis), supplying nutrition for neurons, and
recycling neurotransmitters.
Therefore the answer to
this question would be:
<span>“Astrocytes”</span>
Answer:
The head, which is the top of the bone that fits into the shoulder joint. ... The anatomical neck is the portion that lies just below the head. As the neck continues along the humerus body, it is called the surgical neck (so named because this is the location of many fractures that require surgery)
Explanation:
Answer:
The correct answer is B.
Explanation:
The fibroblast is a dynamic cell, which exerts tissue functions at the local level and the immune system. Among its main functions is the formation of connective tissue fibers called collagen and elastin; The fibroblast performs other equally important roles such as: The production and maintenance of the fundamental substance in which its fibrous products are embedded, it has the ability to synthesize and phagocytize collagen and extracellular matrix components in connective tissue remodeling processes.