What is the genome?
It is all the genes in a nucleus
It is all the genetic material in an organism
It is all the DNA in a human being
Which base pairs with guanine (G)?
thymine
adenine
cytosine
Why is phenylketonuria an example of how variation can be caused by the genes and environment working together?
Phenylketonuria is caused by a defective gene which codes for a defective enzyme
Phenylketonuria only develops when someone eats food containing phenylalanine
Individuals with a defective PAH gene cannot metabolise phenylalanine and so must exclude it from their diets to stay healthy
What is a protein?
It is a polymer made of many amino acids joined together
It is a polymer which determines how an organism develops and functions
It is an enzyme
What is the difference between an allele and a genetic variant?
Alleles are all the possibilities for a gene, but genetic variants describe how organisms are different
All the possible versions of a gene are genetic variants, but each individual only has two alleles for each gene
Genetic variants are caused by mutation of a gene’s DNA, but alleles have always been normal
What is the difference between an organism’s genotype and its phenotype?
Its genotype consists of the genetic variants that it has, while its phenotype is the features that result from the interaction of its genome and the environment
Its phenotype is caused by the environment but its genotype is not
Its genotype includes all the information in its genome, but its phenotype is just how the environment affects its genotype
Which is a correct example of base pairing? - Higher
Guanine (G) pairs with adenine (A)
Thymine (T) pairs with cytosine (C)
Adenine (A) pairs with thymine (T)
The original base sequence of a sample section of DNA is GGTACAA. Which kind of mutation has occurred to result in the variant GCGTACAA? - Higher
Deletion
Insertion
Point (substitution)
What is a triplet code? - Higher
It is a sequence of three amino acids that can be read by a ribosome
It is a sequence of three bases that codes for a particular amino acid
It is a sequence of three nucleotides that codes for a particular amino acid
What does a ribosome do? - Higher
It reads the genetic code of DNA to assemble nucleotides into mRNA
It reads the genetic code of DNA to assemble amino acids into a protein
It reads the genetic code of mRNA to assemble amino acids into a protein