IB Biology HL A1.2.9 Diversity of Dna Base Sequences Questions

a. four bases in DNA / bases in DNA are adenine cytosine guanine and thymine

OR

four bases in RNA / bases in RNA are adenine cytosine guanine and uracil;

b. purines and pyrimidines

OR

uracil instead of thymine in RNA;

c. bases/nucleotides can be arranged in any sequence;

d. many/4 ${ }^{\mathrm{n}}$ possible permutations/combinations/sequences (of the four bases)

OR

64 possible triplets of bases/codons;

e. nucleic acids/RNA/DNA can have any number of nucleotides / unlimited in length;

f. mutations can change base sequence/increase diversity;

g. many different proteins/proteins so many sequences needed to code for them;

h. three/triplet of bases needed to code for each amino acid

OR

degeneracy of genetic code/more than one codon per amino acid;

Marking guidance:

Award mark point a and mark point b if the answer includes the four bases in both DNA and RNA.

Do not accept letters instead of base names in mark point a.

Mark points d and g are different: mark point d is for the idea that the four bases in any sequence gives many possible base sequences;
mark point g is for the idea that the many different proteins necessitate many different base sequences in the genome.

4
max