That should be the cell membrane. The cell membrane acts as a filter in and out.
A mutation that involves one or a few nucleotides is called
a) mutagen
b) inversion
c) point mutation
d) translocation
Answer:
c) point mutation
Explanation:
When only one or a few nucleotides of a gene are changed by mutation, this is called a point mutation. A point mutation can add one additional nucleotide to the wild type gene or may delete or substitute a nucleotide from it. For example, if a wild type gene sequence is "ATATATATA", then the addition of "C" at the position 4 will change it into "ATACTATATA". This addition of new nucleotide is called point mutation since only one nucleotide is added to the gene. Point mutations can cause serious genetic disorders such as sickle cell anemia.
I would say B) <span>The shoot is positively phototropic and negatively gravitropic; the root is positively gravitropic and negatively phototropic.
This is because the shoot of the plant is attracted towards the sun, as the chloroplasts in the leaves need sunlight to make food. As well, the roots are attracted downward to absorb more water and minerals from the sun.
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They would constrict the diameter of blood vessels. Plaque and tobacco can block your arteries, inhibiting from doing their job.
