2. DNA, chromosomes, genes What is a gene? Triplet code? Compare prokaryotic and eukaryotic DNA.

3. Give three ways in which the DNA of prokaryotic and eukaryotic cells differ? Page 205 will help! Why are mitochondria and chloroplasts special?

4. Genes Each chromosome contains the genetic code for many polypeptides. The code for a single polypeptide is called a gene Loci of different genes

5. 2% of DNA codes for polypeptides Some non-coding DNA is found within the gene, some inbetween genes = introns. Coding regions are called exons

6. Not all non-coding ‘junk’ It’s not fully understood but some codes for functional RNA, including ribosomal RNA and transfer RNAs.

7. The Triplet Code A codes for amino acid 1 T codes for amino acid 2 C codes for amino acid 3 G codes for amino acid 4 A singlet code could not provide the necessary information for the utilisation of the 20 different amino acids known to be required for the synthesis of the diversity of proteins found in living organisms

8. A doublet code allows for sixteen different combinations of the nucleotide/base sequence CGCCCACTC GGGCGAGTG AGACAAATA TGTCTATTT GCAT 2 nd Position 1 st Position A doublet code could still not provide the necessary information for the utilisation of 20 different amino acids

9. A triplet code allows for sixty four different combinations of the nucleotide/base sequence G GGGGAGGCGGTG A GGAGAAGCAGTA C GGCGACGCCGTC T GGTGATGCTGTT G G AGGAAGACGATG A AGAAAAACAATA C AGCAACACCATC T AGTAATACTATT A G CGGCAGCCGCTG A CGACAACCACTA C CGCCACCCCCTC T CGTCATCCTCTT C G TGGTAGTCGTCG A TGATAATCATCA C TGCTACTCCTTC T TGTTATTCTTTT T GACT 3 rd Position 2 nd Position 1 st Position

10. universal, non-overlapping and degenerate

11. Triplet code a sequence of three nucleotides codes for the synthesis of a specific amino acid Model a length of DNA by listing at least 21 nucleotide bases And then build a complementary list of bases to complete the molecule

12. The process by which DNA is ‘read’ to produce a strand of mRNA A G T C G T C A A T G C T A T G C A T T C C G T A C T C A G C A G T T A C G A T A C G T A A G G C A T G DNA mRNA A G U C G U C A A U G C U A U G C A U U C C G U A C RNA polymerase Coding Strand Template Strand 5’ 3’ TRANSCRIPTION

13. A G U C G U C A A U G C U A U G C A U U C C G U A C G Remember our strand of mRNA from before? U C AG C AG U UA C GA U AC G UA A GG C AU G C SER ALA VAL THR ILE ARG LYS TRANSLATION

14. Using your model strand of mRNA Now create a chain of amino acids to from your very own protein. Use the table on the genetic code worksheet