Answer:
There is a great difference between light and scanning electron microscope. The source of illumination is light rays in light microscope while in scanning electron microscope electrons are the source of illumination.
The resolving and magnification power of scanning electron microscope is much greater than that of a light microscope. The magnifying power of a light microscope is 1000X and of electron microscope is 10,00,000X.
In light microscope image is seen through the eyepiece while in scanning electron microscope it is seen on a fluorescent screen. Even small specimens up to 0.1 micrometers can be seen by scanning electron microscope which is not possible to see by light microscope.
Answer:
The type of mutation responsible for changing a base in the mRNA strand, without changing the coding aminoacid or protein, is called a <u>silent</u> mutation.
Explanation:
In a silent mutation occurs the change of a nitrogenous base in one of the codons that encodes an aminoacid, without changing the aminoacid or altering the structure or function of the protein to be synthesized.
In this type of mutations the change of the base does not mean the change of the aminoacid, because some aminoacids can be coded with more than one codon. In the case of Leucine, the codons that encode it are CUU, CUC, CUG or CUA, so even if a base changes, the final protein will be the correct one.
For the other options:
- <u><em>Missense</em></u><em>: the change of the base in the DNA chain implies the change of the codon in the mRNA and of the encoded aminoacid, in that way a structural and functional alteration of the synthesized protein occurs. </em>
- <u><em>Nonsense</em></u><em>: the change in the nitrogenous base in the DNA leads to the coding of a termination codon, so that the protein is ultimately incomplete.</em>
- <u><em>Insertion</em></u><em>: in this case there is the addition of more nitrogenous bases to the DNA chain, with respect to the original one.</em>
Yes, the DNA replication proceeds in one direction.
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They can’t live in dry areas because fungi need to be able to trap moisture since their broad tops can dry out
Answer:
Producing and exporting organs in the plant (typically mature leaves) are known as sources, while non-photosynthetic organs (fruits, roots and tubers) and immature leaves are known as sinks.
Explanation: