The substances that protect against oxidative stress and the resultant tissue damage at the cellular level is, option B. Antioxidants. Oxidation can cause imbalance in the body. Antioxidants are used to counteract the damage produced by free radicals. Good natural sources of antioxidants include fruits and vegetables.
Answer:
RNA polymerase binds to the promoter
Polymerase initiates RNA synthesis at the start point on the template strand
RNA polymerase moves downstream unwinding the DNA
RNA transcript is released and polymerase detaches from the DNA
The pre-RNA undergoes processing
Explanation:
The promoter is the specific DNA sequence that serves as a binding site for RNA polymerase. The enzyme RNA polymerase recognizes the promoter sequence and binds to it to begin the process of RNA synthesis. The process of RNA synthesis begins at the start site where the process of the unwinding of DNA duplex is initiated.
The unwinding separates the two DNA strands at the start site where RNA polymerase begins the process of synthesis of the new RNA strand. The newly formed RNA strand and RNA polymerase are released from the template strand after the termination of the process.
In eukaryotes, the primary RNA transcript undergoes the process of splicing of introns, the addition of poly-A tails and 5' cap which in turn transform it into the mature mRNA.
Answer:
During the S phase at interphase in meiosis I
Explanation:
During the S (DNA synthesis) phase at interphase in meiosis I, DNA replication occurs here where the chromosomes are doubled. This phase does not occur in meiosis II. At the end of meiosis II, the chromosome number becomes halved in the sex cells. The cell just goes on to divide to ensure haploidy of chromosomes in the gametes such that the sperm from the male and egg from female are both haploid. Fertilization brings about diploidy of the zygote itself