Answer:
1) A, C and D
2) D
Explanation:
The normal hemoglobin is made up of heme and globin. The protein, globin is in turn made up of four polypeptide chains which include two alpha and two beta chains.
The gene gene responsible for the creation of the beta globin chain is located on the short arm of chromosome eleven. It is called the HBB gene. Many mutations occur on the HBB gene and a mutation on this gene produces abnormal hemoglobin like HBS, hbc, and hbe. HBs causes sickle cell anemia.
In sickle cell anemia, there is an alteration of the genetic code, leading to the substitution of a single amino acid where glutamic acid is replaced by valine in the sixth position of the beta chain.
In the mRNA, the change converts a glutamic acid codon(GAG or GAA) to a valine codon(GUA, GUC, GUU or GUG).
Sickle cell anemia is caused by a transversion that leads to a missense mutation.
b. radioactivity
The process by which atomic nuclei spontaneously decay is called radioactive decay. Explanation : This is also known as nuclear decay on a general basis In this process of radioactivity the unstable atomic nucleus loses energy .
Water cycle affects ocean salinity on different levels.
For example, evaporation of ocean water increases the salinity of the ocean, while precipitation and melting of ice decrease it, achieving the balance. Temperature, salinity and water cycle are tightly connected. As global temperatures rises, evaporation increases, and so the salinity. Salty ocean has a tendency to sink. On the other hand warmer ocean rises to the surface and this has influence on ocean currents which then impact the weather.
