Ribosomes produce the proteins
Leukemia can be treated using human stem cells to attack and destroy cancer cells.
Answer:
Option (a) and (d).
Explanation:
The breaks in DNA molecule may occur due to replication error and oxidizing agent. The double-stranded breaks in DNA can be corrected by Homologous end joining and non homologous end joining.
Homologous end joining is used to repair the DNA present in G2 nad S phases of the cell cycle. The homologous sequences of DNA is used to repair the DNA. Non homologous end joining occurs in the cell present at G0 and G1 phase of the cell cycle. The DNA broken ends are juxtaposed and later rejoin together by DNA ligase.
Thus, the correct answer is option (a) and (d).
<h2>The given statement is true</h2>
Explanation:
Iron absorption occurs in the duodenum and upper jejunum of small intestine
- At physiological pH ferrous iron is rapidly oxidized to the insoluble ferric form
- Gastric acid lowers the pH in the duodenum which enhances the solubility and uptake of ferric iron
- Once iron gets inside the enterocyte it can be stored as ferritin;Ferritin is a hollow spherical protein which helps in storage and regulation of iron levels within the body
- Ferritin molecule have ferroxidase activity which helps in the mobility of Fe2+ out of the enterocyte by ferroportin
- Transferrin is the major iron transport protein which transports iron through blood
- Fe3+ binds to transferrin so Fe2+ transported through ferroportin must be oxidized to Fe3+
- Fe2+ needs to be oxidized first so that it can be transported through ferroportin
- Once iron gets inside the cell it can be used for various cellular processes
