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:
Natural selection results in evolution.
Explanation:
Natural selection is the separation of types of individuals in different environments, like geographical isolation. Due to this, the offspring will soon evolve and create a new species, known as evolution.
I think its false because gas exchange can happen in blood also
Answer:
B I think
Explanation:
If not try D I know it's a if,then statement
Answer:
HEREDITY ONLY:
none
GENETIC VARIATION ONLY:
none
BOTH:
all
Explanation:
In all the organism that reproduce sexually, produced offspring are genetically varied. As this genetic variation continues, it also leads to hereditary evolution of organism through gene flow from one generation to other. Therefore, the processes of DNA replication, crossing over, chromosome separation and alignment etc. ensure flow of genes from one generation to the next. This does not happen in organisms reproducing asexually.
