C02 DNA and Gene Expression

B2.1      Know and understand that

1. the genome is the full set of genetic material (DNA) of an organism.
2. this DNA is contained within chromosomes.

B2.2      Know and understand the structure of DNA:

1. Know and understand that single-stranded DNA (ssDNA) is a polymer made up of nucleotides joined together to form one strand of DNA.
2. Know and understand that double-stranded DNA (dsDNA) is a polymer made up of two strands of DNA forming a double helix.
3. Know and understand that the structure of each nucleotide consists of a common sugar and phosphate group as well as one of four different nitrogenous bases.
4. Know the complementary pairs of DNA nitrogenous bases – adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C) – and that the sequence of these bases is the genetic code.

B2.3      Protein synthesis:

1. Know and understand that protein synthesis involves producing chains of amino acids called polypeptides.
2. Know and understand that one or more polypeptide(s) can form a functional protein.
3. Know and understand that the three-dimensional shape of a protein is determined by the sequence of its amino acids.
4. Know and understand that the sequence of nucleotide bases in a gene determines the sequence of amino acids in the polypeptide the gene codes for.
5. Know and understand that the sequence of nucleotides in a gene is ‘read’ as triplets, and that each triplet codes for an amino acid.

B2.4      Gene mutations:

1. Understand that a mutation changes the sequence of nucleotides in the DNA.
2. Know that most mutations have no effect on the phenotype, some will have a small effect, whilst occasionally others will determine the phenotype.