The rock cycle is a cycle that rocks go through which involves melting, cooling, pressure, erosion, and other stages. Starting with a volcanic eruption, the lava turns into igneous rock, that can be melted into magma again, or can be crushed and pressed into other rocks beneath the crust to form metamorphic rock, or can be broken down by erosion and other factors. For the sake of it, let's say the rock got broken down, it turns into sediment that collects in areas and get layered and pressed, and layered, and pressed some more into a sedimentary rock. That rock can be broken down again, or melted, or pressed with heat and pressure. But let's say it went under the crust with other rocks, mixed with heat, pressure, and other types of rock to become metamorphic rock. Now let's say that metamorphic rock found it's way to a volcano, got melted, and erupted, and cooled to get back to a igneous rock. And the cycle never ends.
The hydrosphere is the combined mass of water found on, under, and above the surface of [the earth.] ⦁ The word comes from the Greek words for "water" and "sphere." ⦁ The hydrosphere includes water in liquid and frozen forms in groundwater, oceans, lakes and streams
When blood calcium levels drop, glands embedded in the posterior thyroid secrete parathyroid hormone, which stimulates osteoclastic activity. It is made up of parathyroid glands that lie behind the thyroid glands. The reason why it is important because it controls calcium level in the blood and within the bones. It controlled by the low calcium levels in the blood it restorative parathyroid secretion whereas the high calcium levels in the blood stop the release of parathyroid hormone.
<span>. Messenger RNA (mRNA) is
synthesized from a gene segment of DNA which ultimately contains the
information on the primary sequence of amino acids in a protein to be
synthesized. The genetic code as translated is for m-RNA not DNA.
The messenger RNA carries the code into the cytoplasm where protein
synthesis occurs. The cell does
not contain large quantities of mRNA. This is because mRNA, unlike other RNAs
is constantly undergoing breakdown.
2. In
the cytoplasm, ribsomal RNA (rRNA) and protein combine to form a
nucleoprotein called a ribosome. The ribosome serves as the site and
carries the enzymes necessary for protein synthesis. The ribosome attaches
itself to m-RNA and provides the stabilizing structure to hold all substances
in position as the protein is synthesized. Several ribosomes may be attached to
a single RNA at any time. </span>
<span>
3. Transfer
RNA (tRNA) contains about 75 nucleotides, three of which are called
anticodons, and one amino acid. The tRNA reads the code and carries the
amino acid to be incorporated into the developing protein. Part of the
tRNA doubles back upon itself to form several double helical sections. The
tRNA "reads" the mRNA codon by using its own anticodon. The actual
"reading" is done by matching the base pairs through hydrogen bonding
following the base pairing principle. Each codon is "read" by various
tRNA's until the appropriate match of the anticodon with the codon occurs.</span>
The part of the atom which is involved in chemical bonding with other atoms is called Valence Electrons. Hope this helps :)
