The sensory receptors refer to the portions of the nervous system, which sense variations in the external or internal surroundings. The sensory input can be in various forms, comprising taste, pressure, light, sound, pH of blood, or levels of hormones, which are transformed into a signal and are transmitted to the brain or spinal cord.
In the sensory centers of the brain, the barrage of information is integrated and a response is produced. The response, that is, a motor output refers to a signal conducted towards organs via motor neurons, which then transforms the signal into some kind of action, like changes in heart rate, movement, discharge of hormones, and others.
Homogeneous is the answer
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>.
It is a mode of asexual reproduction in single-celled eukaryotic micro organisms
It usually occurs in archaea bacteria, fungi , amoeba etc....
