How many amino acids could be specified if codons consisted of two nucleotides instead of three? What problem would this present for an organism making proteins using all 20 amino acids? I need help with the last part i dont undertsand

This could result in a mutation.

Explanation:

A change in the DNA can affect the work of cells because it can cause a mutation; it can be a good mutation or bad. The three main mutations that occur are Insertion, Deletion and Substitution. Insertion is when DNA base(s) are added in, Deletion is when DNA base(s) are removed. Lastly, Substitution is when DNA base(s) are switched on. All of these mutations can have effects. These effects are Silent effect, Missence, and Nonsense. Silent effect is a mutation that does not change the sequence of amino acids in a protein. Missence is a mutation that causes the sequence of amino acids to change. This can cause incorrect protein folding and protein malfunction. Nonsense is a mutation that causes an early stop codon. This effect leads to a protein that is too small. Also a Frameshift can occur. Framshift is when the reading of a frameshift is moved over by one or more bases such that every subsequent amino acid changes. An example of a frameshift is THE CAT ATE THE RAT. If you insert an A at the Beginning this happens ATH ECA TAT ETH ERA T. IN Conclusion there are two Mutations that also play a role in this Point Mutation and Chromosomal Mutaion. Point Mutation is when a single DNA base is either substituted, inserted or deleted from the sequence. Chromocomal Mutation is when large pieces of a chromosome or an entire chromosome is either substituted, inserted or deleted.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

after a the power stroke, adp is released, but the cross-bridge formed is still in place. atp then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.