Genetic Information, Variation and Relationships Between Organisms | AQA A-Level Biology (7402)

Genetic Information, Variation and Relationships Between Organisms

219 questions
18 subtopics
Paper 1, and available on Paper 3
Paper 1 and Paper 3

Genetic Information, Variation and Relationships Between Organisms is examined on Papers 1 and 3 of AQA Biology, which draw on topics 1 to 4.

207 recall questions across 18 subtopics.

Sample questions from Genetic Information, Variation and Relationships Between Organisms

Answer each one closed book first, then open the answer.

Prokaryotic and eukaryotic DNA, chromosomes and histones

Are prokaryotic DNA molecules associated with proteins?

Show the answer
No, prokaryotic DNA is not associated with proteins.
Features of the genetic code, exons and introns

What proportion of nuclear DNA in eukaryotes codes for polypeptides?

Show the answer
Only a small proportion; much of the nuclear DNA does not code for polypeptides.
Transcription, RNA polymerase and splicing

How does RNA polymerase separate the two strands of DNA during transcription?

Show the answer
By breaking the hydrogen bonds between base pairs.
Gene mutations, mutagens and chromosome non-disjunction

What is a base substitution mutation?

Show the answer
A type of gene mutation where one base is replaced by another.
Meiosis compared with mitosis and random fertilisation

How do mitosis and meiosis differ in their effect on chromosome number?

Show the answer
Mitosis maintains chromosome number, whereas meiosis halves chromosome number.
Directional and stabilising selection

Name a classic example of stabilising selection in humans.

Show the answer
Human birth weights.
Selection on birth weight, aseptic technique and antimicrobials

Why is equipment sterilised before use in microbiology?

Show the answer
To kill any microorganisms present and prevent contamination of cultures.
Defining a species, courtship and phylogenetic classification

What is a phylogenetic classification system?

Show the answer
A system that attempts to arrange species into groups based on their evolutionary origins and relationships.

The 18 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Prokaryotic and eukaryotic DNA, chromosomes and histones	Recall questions on the length and shape of DNA in prokaryotic cells and in the eukaryotic nucleus, whether it is associated with proteins, and what chromosomes and histones are.	8
DNA in mitochondria and chloroplasts, genes and loci	Recall questions on the short, circular DNA of mitochondria and chloroplasts, genes that code for polypeptides and for functional RNA such as rRNA and tRNA, and the locus of a gene.	11
Features of the genetic code, exons and introns	Recall questions on base triplets and the universal, non-overlapping and degenerate genetic code, non-coding repeats between genes, exons and introns, and what these features mean for mutations.	12
Genome, proteome, mRNA and tRNA	Recall questions on the genome and the proteome, the single-stranded structure and bases of mRNA, codons, and the clover-leaf structure of tRNA with its anticodon and amino acid binding site.	8
Transcription, RNA polymerase and splicing	Recall questions on anticodons, how RNA polymerase transcribes the template strand into mRNA, how prokaryotic and eukaryotic transcription products differ, and splicing introns out of pre-mRNA.	11
Translation at the ribosome and the role of tRNA	Recall questions on translation, how ribosomes hold mRNA and tRNA, how tRNA anticodons match codons, peptide bonds between amino acids, the ATP used, and how base sequence sets primary structure.	12
Gene mutations, mutagens and chromosome non-disjunction	Recall questions on gene mutations such as base deletion and substitution, why degeneracy makes some substitutions silent, mutagenic agents, and changes in chromosome number by non-disjunction.	9
Meiosis, independent segregation and crossing over	Recall questions on the two nuclear divisions of meiosis and the haploid, genetically different cells it makes, and how independent segregation and crossing over create genetic variation.	8
Meiosis compared with mitosis and random fertilisation	Recall questions on what separates in the first and second meiotic divisions, how meiosis and mitosis differ, random fertilisation, and calculating the possible chromosome combinations from n homologous pairs.	11
Genetic diversity and the spread of advantageous alleles	Recall questions on genetic diversity as the number of alleles, why natural selection needs it, how new alleles arise by mutation, and how an advantageous allele becomes more frequent over generations.	12
Directional and stabilising selection	Recall questions on directional selection and its example in antibiotic resistance, stabilising selection and human birth weight, their effects on mean phenotype and variation, and structural and biochemical adaptations.	9
Defining adaptations and how antibiotic resistance spreads	Recall questions on anatomical, physiological and behavioural adaptations, and how a resistance allele arises, survives antibiotic exposure and increases in frequency in a bacterial population.	9
Selection on birth weight, aseptic technique and antimicrobials	Recall questions on stabilising selection in human birth weight, the aseptic techniques used when culturing microorganisms, measuring antimicrobial effectiveness by zones of inhibition, and logarithmic scales.	12
Classifying anatomical, physiological and behavioural adaptations	Recall questions on the three categories of adaptation and on classifying examples such as a camel's hump, migration, an Arctic fox's fur and ears, concentrated urine and nocturnal hunting.	9
Defining a species, courtship and phylogenetic classification	Recall questions on how a species is defined, why courtship behaviour matters for successful mating, how a phylogenetic classification arranges species into taxa, and the first ranks of the hierarchy.	11
The taxonomic hierarchy, binomial names and molecular evidence	Recall questions on the ranks from domain to species, writing binomial names such as Homo sapiens, and how genome sequencing and immunological comparisons clarify evolutionary relationships.	18
Species richness, the index of diversity and farming	Recall questions on species richness and its limits, calculating an index of diversity, and how monoculture, herbicides, pesticides and hedgerow removal reduce biodiversity and how farmland can be conserved.	17
Comparing genetic diversity, standard deviation and the t-test	Recall questions on comparing genetic diversity using characteristics, DNA, mRNA and amino acid sequences, random sampling, mean, median, mode and standard deviation, and choosing and using statistical tests.	32

Genetic Information, Variation and Relationships Between Organisms is 219 of the 1,977 questions in the guide.Get the guide, £8

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.