Answer: The reason is because DNA polymerase which is the enzyme that catalyzes the synthesis of DNA has a 3'->5' exonuclease activity that double-checks each nucleotide after it is added.
Explanation: The 3'->5' exonuclease activity of DNA polymerase allows the enzyme to double-check and remove a newly added wrong nucleotide. It is highly specific for mismatched base pairs. When the DNA polymerase adds a wrong nucleotide to the growing strand, translocation of the enzyme to the position where the next nucleotide is to be added is halted, but the exonuclease activity of the DNA polymerase removes the incorrectly paired nucleotide so that replication can continue. The process of double-checking a newly added nucleotide and removal of any incorrectly paired nucleotide by the DNA polymerase is called proofreading.
Answer: the leaves
Explanation:
the leaves take in energy and rays from the sun, hence photosynthesis.
Answer:
Graph A: Directional Selection
Graph B: Stabilizing Selection
Graph C: Disruptive Selection
Explanation:
Natural selection as a driving force of evolution cam be defined as a process that a population of organisms undergo in other to become adapted to an environment and survive to produce offspring that are fitter.
Thus, the following graphs represents the three types of natural selection:
Graph A: Directional Selection
Directional selection occurs when one extreme trait is favoured over others by selective pressures.
The graph shows that only one extreme trait is favoured as the population that survives seem to have majorly a particular extreme trait.
Graph B: Stabilizing Selection
In this type of natural selection, neither of the extreme traits are favoured by selective pressures. Therefore, intermediate trait become favoured over the other extreme traits.
Graph C: Disruptive Selection
Selective pressures works against the intermediate trait while both extreme trait at the spectrum are well favoured, which become more established in a population against the intermediate trait.
Answer:
Mammals first appeared
Explanation:
The dinosaurs became extinct one million years after the Cenozoic era started. The mammals first appeared as the modern culture first appeared in that era.