Answer:
The importance of the AUG and UGA bases lies in the fact that the first one is a start codon and the second one is a stop codon, respectively (option a).
Explanation:
Codons or triplets are sequences of three nitrogenous bases, in the mRNA, that determine the synthesis of a specific amino acid.
- <em>AUG </em><em>is called the </em><em>initiation or start codon</em><em>, and is usually at the beginning of a peptide synthesis, in addition to encoding the amino acid methionine.
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- <em>UGA</em><em> is a</em><em> termination or stop codon</em><em> found at the end of a petid chain when it is complete. UAA and UAG codons are also STOP or termination codons and, together with UGA, do not code for amino acids.</em>
The biological importance of start and stop codons is to initiate the synthesis of a protein and to stop the addition of amino acids when their size is adequate.
Microfilaments
Microfilaments are fine, thread-like protein fibers, 3-6 nm in diameter. They are composed predominantly of a contractile protein called actin, which is the most abundant cellular protein. Microfilaments' association with the protein myosin is responsible for muscle contraction. Microfilaments can also carry out cellular movements including gliding, contraction, and cytokinesis.
Microtubules
Microtubules are cylindrical tubes, 20-25 nm in diameter. They are composed of subunits of the protein tubulin--these subunits are termed alpha and beta. Microtubules act as a scaffold to determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. Microtubules also form the spindle fibers for separating chromosomes during mitosis. When arranged in geometric patterns inside flagella and cilia, they are used for locomotion.
Hope this helps :)
the main property is flammability
