The genetic code 0.0 / 5 ? BiologyDNA, genetics and evolutionASWJEC Created by: zoolouiseCreated on: 06-04-16 16:56 How is genetic information coded? It's coded in the sequence of bases in DNA, it's contained in the genes. 1 of 16 What did experiments show about a polynucleotide strand? Experiments showed that a polynucleotide strand always had there times the number of bases than the amino acid it coded for. 2 of 16 What happens if three bases were removed or added to the polynucleotide strand? The polypeptide chain would be one amino acid shorter or longer. 3 of 16 What does triplet mean? Three bases code for one amino acid. 4 of 16 How many possible codes are there? There's 64 possible codes but only 20 amino acids are found in proteins. 5 of 16 What dose punctuated mean? Three triplet codes do not code for an amino acid. In mRNA these are stop codons which mark the end of a portion to be translated. 6 of 16 What dose universal mean? In all known organisms, the same triplet codes for the same amino acids. 7 of 16 What does non-overlapping mean? Each nucleotide only belongs to one triplet code, therefore they're distinct triplets. 8 of 16 What is a codon? A codon is a triplet of bases in mRNA that codes for a particular amino acid. 9 of 16 What does DNA contain? DNA contains the information for making polypeptides/proteins and an RNA version is first made from the DNA. 10 of 16 What is the RNA in prokaryotes? In Prokaryotes this RNA is mRNA and directs the synthesis of the polypeptixde. 11 of 16 What is this RNA in eukaryotes? In Eukaryotes the RNA has to be processed first. 12 of 16 Why is the initial RNA version of the code longer than the final mRNA in eukaryotes? As it contains sequences of bases that have to be removed. 13 of 16 What are introns? Introns are the sequences to be removed, these aren't translated to proteins. 14 of 16 How are introns cut out of pre-mRNA? Introns are cut out of pre-mRNA using endonucleases. 15 of 16 What are the sequences left after introns are cut out of pre-mRNA? The sequences left are exons, these are joined together with ligases. 16 of 16
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