Answer:
1. The difference between the normal hemoglobin protein DNA sequence and the sickle cell hemoglobin DNA sequence is a base to base shift, in this case adenine (GAG) to thymine (GTG).
2. The difference affects the amino acid sequence of the protein by replacing glutamic acid (Glu) with valine (Val).
Explanation:
In sickle cell anemia, a change in the DNA nucleotide sequence is observed, where adenine is substituted by thymine, whose expression is the change in the amino acid sequence of globine β, incorporating valine instead of glutamic acid. This represents a molecular mutation - point mutation - by subtitution, which corresponds to missense mutation.
<u>Normal hemoglobin protein in a RBC</u>
DNA CTG ACT CCT GAG GAG AAG TCT
Amino acids Leu Thr Pro Glu Glu Lys Ser
<u>Sickle cell hemoglobin protein in a RBC</u>
DNA CTG ACT CCT <em>GTG</em> GAG AAG TCT
Amino acids Leu Thr Pro <em>Val</em> Glu Lys Ser
When GAG is transcribed to mRNA, the CUC codon is obtained, which codes for glutamic acid. Thymine substitution causes the DNA sequence to change to GTG, which is transcribed as CAC, the codon that encodes the amino acid valine. The <u>change from glutamic acid to valine in β-globin causes an altered hemoglobin, giving the abnormal erythrocytes observed in sickle cell disease</u>.
Answer:
B. Earth's rotation around its axis
Explanation:
Answer:
Transcription and RNA processing (splicing)
Explanation:
Although Howard is almost right, the DNA sequence does not precisely relate to the protein sequence. First of all, the DNA is transcribed to an primary mRNA molecule. Bur before the mRNA is ready to be translated into an amino acid sequence, it must be processed into a mature mRNA.
This includes adding a 3' poly A tail, and a 5' cap, and importantly for this question, splicing.
Splicing is the removal of non protein coding intermediate sequences called introns from the protein coding regions (exons) of a primary mRNA. This means that lots of the DNA sequence is not dictated by the final protein, as many of the intervening sequences have been removed by splicing.
They are rich in hydrogen and helium, they have unlimited supply of hydrogen, they have a strong gravitational pull.
Explanation:
Space where huge size of gaseous and dust cloud is present is called nebula. It is mainly made of hydrogen and helium. Nebula exist in the space which is between the stars and it is call as interstellar space.
Helix nebula is closest nebula which is near the earth. It’s distance from earth is about 700 light years.
Dark nebulae are very dense as well as cold. Nebula can be divided into dark nebula and bright nebula. The gas which is present between the stars is always combine with solid grains cosmic dust.
