Answer:c. DNA polymerase can join new nucleotides only to the 3′ end of a pre-existing strand.
Explanation:
The double stranded molecule of DNA having the pairing strands in the anti-parallel condition. One strand is remain in configuration as the 5’ to 3’ end, the complementary strand is positioned 3’ to 5’ end.
New DNA strand synthesis occurs from the 3’ to 5’ end as the enzyme DNA polymerase attach itself to the 3’ end of a DNA strand. It will add new nucleotides to the 3' end of the DNA.
Hence, the option (c) is the correct answer.
Answer:
Answer is C.
Explanation:
For A and B, a base substitution affects one of the three bases that comprise a codon, the DNA/RNA unit that corresponds to a particular amino acid. If one base is substituted, one codon and therefore one amino acid will be affected. Codons have built-in redundancy, so even by changing one base, the new codon sometimes still corresponds to the same amino acid. Therefore, a base substitution at most affects one amino acid, and sometimes doesn't affect it all.
Frameshift mutations cause a lot more trouble. These occur when you have a deletion or insertion that changes the number of bases in your gene. As a result, the "frame" of the codons changes (everything shifts one way or the other by the number of bases added/removed). This affects EVERY codon downstream of the mutation, so you can imagine that such a mutation would have a bigger effect the closer to the start of the gene it occurs. This is why C is correct.
Answer:
Explanation:
Neurulation is a process in which the neural plate bends up and later fuses to form the hollow tube .which eventually differentiate into the brain and the spinal cord of the central nervous system.
The body's homeostatic control mechanisms ensure that a balance between fluid gain and fluid loss is maintained. The hormones ADH (antidiuretic hormone, also known as vasopressin ) and aldosterone play a major role in this.