D, low sea levels caused the ice age.
Answer:
Because the leading strand is synthesized continuously while the lagging strand is discontinuously synthesized.
Explanation:
Two DNA strands have opposite polarity, that is, the 5' end of one strand lies opposite to the 3' end of the other strand. However, DNA replication can occur in 5' to 3' direction only since the formation of phosphodiester bonds require the presence of nucleophile 3' OH to attack the 5' phosphate of an incoming deoxyribonucleotide.
The problem is solved by the synthesis of the leading strand continuously and the synthesis of the lagging strand in a discontinuous manner. Lagging strand synthesis requires the formation of primers and their elongation to form Okazaki fragments that may have few hundreds to few thousands of nucleotides. Removal of primers from Okazaki fragments is followed by joining them together to make the long lagging strand. The discontinuous replication of the lagging strand makes the replication at the leading strand ahead of it.
Answer AND Explanation:
Respiration by both plants and animals as well as by microorganisms converts some of the organic compounds into carbon dioxide. The latter is released back to the atmosphere and reused by green plants.
The attraction that holds two covalently bonded atoms together is called covalent bond
