Answer:
The correct answer is option - d. Production of primary spermatocytes.
Explanation:
The accessory cells or supporting cells present within the seminiferous tubules of reproductive system termed as the Sertoli cells. They play various roles in the body and reproductive system.
Sertoli cells make blood-testis barrier in adjacent Sertoli cells in the seminiferous tubules. These cells secrete different types of enzymes and hormones such as inhibin which are also secreted by ovary and placenta in females. Sertoli cells produce seminiferous tubular fluid to provide nutrition to the sperm. Apoptotic germ cells are timely eliminated by these cells.
Thus, the correct answer is option D. Production of primary spermatocytes.
I guess I would say b or d. Because concluded results change over time with better technology and some solutions dont work.
Thunder is caused by the extremely rapid expansion of air around a bolt of lightning due to the very high temperature. It is also caused by the change of pressure around a lightning bolt.
Hope that helped you.
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>.
If the water molecule was linear instead of bent, water
would no longer produce hydrogen bonds. It will lose its polar properties and
nearly all of its properties will change such as boiling point, water tension
and solubility. It would be closer to gas, rather than liquid.
