The first cell that was viewed by the light microscope was the oak bark.
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Answer:
b
Explanation:
they chose the best tomatoes to make even better ones
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:
The water potentials (Ψ) of the cell and its surroundings are the same.
Explanation:
When a cell is kept in hypotonic surroundings such as distilled water, the osmotic movement of water occurs towards the cell. The entry of water makes the cell swell up and it becomes turgid. Water potential is determined by solute and pressure potentials mainly. Here, the solute potential of the cell and the distilled water was different resulting in differences in their respective water potential values which in turn served as a driving force for endosmosis.
When the cell is fully turgid, the solute concentration of the cell and the surrounding distilled water become equal to each other. Under these conditions, the water potential of the cell and distilled water are the same.
