This free quiz has 12 real AQA A-level Biology exam questions on species, taxonomy and biodiversity (24 marks, about 30 minutes). It marks itself: tick-box, table and calculation questions are marked for you, and for written answers you check your work against the real AQA mark scheme.
What the quiz covers (AQA 3.4.5–3.4.7)
reading a phylogenetic diagram of how strains evolved
the names of taxa in the hierarchy of classification
defining species and species richness
how organisms are grouped in a phylogenetic classification
what binomial names suggest about evolutionary relationships
how courtship behaviour can be affected
calculating an index of diversity, and how high species richness can go with a low index
comparing genetic diversity, using base sequences and haemoglobin (5 marks)
How to use it
Write each written answer in full before you open the mark scheme. For the index of diversity, write down the values you put into the formula before you work out the answer. Say base sequence and amino acid sequence, not just “DNA” or “amino acids”.
Where students lose marks (from AQA examiners’ reports and mark schemes)
Each point below is followed by wording that gained marks.
Species and species richness. Simpler answers said a species “can make offspring” rather than fertile offspring. Many said species richness is the number of species in a population, or gave the definition of the index of diversity instead.
✔ Gains credit: a species is a group of organisms that can produce fertile offspring; species richness is the number of different species in a community.
Hierarchy with no overlap. Only 5% of students scored both marks for describing phylogenetic classification. A common error was writing about groups within groups without saying there is no overlap.
✔ Gains credit: smaller groups within larger groups, with no overlap, grouped according to evolutionary relationships (common ancestry).
Courtship leads to mating. Students rarely explained that courtship is a behaviour that stimulates or leads to mating. Some said females simply “knew” another fly was female, and “breeding” or “reproduction” on its own was ignored.
✔ Gains credit: courtship behaviour stimulates mating, so less courtship means less mating and fewer offspring.
Sequence of bases. A common wrong answer was “sequence of DNA” rather than “sequence of bases in DNA”. Others wrote about “comparing the DNA” or comparing amino acids without mentioning their sequence, or gave courtship.
✔ Gains credit: compare the base sequence of DNA or mRNA, or the amino acid sequence of the same polypeptide or protein.
Mutations build up. 56.4% of answers about haemoglobin and relationships gained no credit. Many wrote about protein structure or adaptations, said “mutations in amino acids”, or vaguely said the species share a common ancestor.
✔ Gains credit: mutations change the base sequence, which changes the amino acid sequence; mutations build up over time, and distantly related species have an earlier common ancestor.
Food sources, not “less food”. Imprecise terms such as “less food”, “less homes” and “less shelters” lost marks. Very few students linked the loss of hedges or plants to the loss of plant or insect species.
✔ Gains credit: fewer plant or insect species, so fewer food sources (less variety of food) and fewer habitats or niches.
Dominated by a few species. Asked how a year could have the highest species richness but the lowest index of diversity, only 7% scored both marks. Many said each or all species were present in small numbers.
✔ Gains credit: there were many different species, but one or a few species were present in very large numbers (the community was dominated by a few species).
Keep practising
The other AQA 3.4 self-marking quizzes: DNA, genes and chromosomes · Protein synthesis · Mutation and meiosis · Natural selection
Topic 3.3 quizzes start with surface area to volume ratio
The AQA topic index
weekly AQA group classes: Year 12 on Tuesdays at 5.15pm, Year 13 on Wednesdays or Thursdays at 6.30pm
Questions © AQA, from past A-level and AS Biology papers, with their mark schemes and examiners’ reports.