a. A translation stop codon is added at the 3' end of the pre-mRNA.
c. A poly-A tail (50-250 adenine nucleotides) is added to the 3' end of the pre-mRNA.
d. Coding sequences called exons are spliced out by ribosomes.
Explanation:
In eukaryotes, during protein synthesis, the RNA must exit nucleus through the pores on the nuclear membrane and enter into the cytoplasm to undergo translation.
The exit processes of mRNA are: the 5’ capping, 3’ Poly-A tail, and pre-mRNA splicing.
The 5’capping is the initial step with addition of 7-methylguanosine cap to the 5’ end of the mRNA by phosphate linkage. This process protects the mRNA from degrading and helps to initiate translation processes.
The 3’ Poly-A tail step is the cleaving of pre-mRNA and addition of addition of around 200 A nucleotides or the 3’poly (A) tail to the mRNA by the poly (A) polymerase enzyme protein complex. This prevents pre-mRNA degradation, facilitates movement of mRNA to the cytoplasm, and initiates translation.
Pre-mRNA splicing is done to remove the introns from the mRNA because they are not part of function protein coding. The exons which take part in protein coding sequence are spliced once the introns are excised.
Finally, the resultant mRNA will exit the nucleus and enter the cytoplasm to undergo translation
.
Answer:
You should try to determine the nature of the complaint and rule out and treat any immediate life-threatening airway, breathing and circulation problems
Explanation:
The answer is letter A.
There are some people who take illegal substances in the body as a result of an underlying insecurity or lack of emotional support. Some narcotic drugs out there are meant to suppress appetite which then causes people who are dependent on them to develop eating disorders. Stimulants like amphetamines cause an excessive change in behavior and eating habits which would result eventually to eating disorders. People who are known to have a substance abuse problem must always seek the help of professionals in order to resolve and regress past issues.
