A cotyledon is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon usually becomes the embryonic first leaves of a seedling.
<span>Sensations of somatic distress in waves lasting from 20 minutes to an hour at a time, a feeling of tightness in the throat, choking with shortness of breath, need for sighing, an empty feeling in the abdomen, lack of muscular power. This is a classic description of Acute grief or grief syndrome. Grief syndrome may appear immediately after a crisis. It is a set of symptoms that are associated with loss.
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Answer:
Because of the several steps with high temperatures and also (heavy ) changes in temperature.
Explanation:
PCR consists of a serie of 20–40 repeated temperature changes. Those series or cycles are also called thermal cycles.
The individual steps (common to most PCR methods) are as following:
→Denature template : 99 °C for 2 minutes
→Anneal primers to template : 55 °C for 2 minutes
→Extension of the primers by heat stable DNA polymerase :72 °C for 2 minutes
As we can notice, will in a relatively short time, different temperatures be used. It's important that the used polymerase will be functional at corresponding temperatures, as well as (heavy) temperature changes.
→ Since the bacteria Thermus aquaticus lives near thermal vents in the ocean floor and grows at temperatures of up to 98°C, it's used to corresponding temperatures.
If other enzymes will be used, i.e enzymes functional in lower temperatures (several) steps will not continue or will not be executed properly. To avoid this it's important to use the best temperature resistant enzymes.
The intermediate molecule that is synthesized to carry the information coded in the DNA is RNA.
According to the central dogma the DNA gets converted to RNA by the process of transcription. Transcription synthesizes the RNA copy of the DNA segment with the help of an enzyme RNA polymerase. RNA then gets converted to protein by the process of translation.
The enzyme DNA polymerase is responsible to convert a single double-stranded DNA molecule to two double-stranded DNA molecules as its products. The DNA is converted to RNA through the transcription process. The enzyme RNA polymerase develops RNA molecule which is complementary to a gene-encoding DNA segment. Translation makes proteins from mRNA molecules. The ribosome is responsible to generate the polypeptide chain of amino acids using mRNA as a template. The polypeptide chain then folds up and becomes a protein.