Voice of the Genome

What Voice of the Genome covers

Covers the cell as a unit: the ultrastructure of prokaryotes and eukaryotes, mitosis and meiosis, gametes and fertilisation, stem cells and how gene expression makes one cell different from another.

The 16 subtopics

Each one has its own page. Edexcel AS Biology A students sit this topic in the first year.

• Prokaryotic cellsRecall questions on the cell wall, capsule, plasmids, flagella, pili and mesosomes, and on how prokaryotic DNA and ribosomes differ from eukaryotic.Open →
• Eukaryotic organelles and their functionsRecall questions on the nucleus, ribosomes, endoplasmic reticulum, mitochondria, lysosomes, centrioles and the Golgi apparatus.Open →
• Identifying organelles in an electron micrographRecall questions on what each organelle looks like under the electron microscope.Open →
• Protein secretion, and levels of organisationRecall questions on the route a protein takes from ribosome to cell surface, and on cells, tissues, organs and systems.Open →
• Microscopy: the graticule, magnification and standard formRecall questions on using a graticule, the magnification formula and rearranging it, and on standard form.Open →
• The cell cycle and the stages of mitosisRecall questions on interphase and the mitotic phase, why mitosis matters, and what happens in prophase, metaphase, anaphase and telophase.Open →
• Core practical: the root tip squashRecall questions on preparing a root tip squash, the stains used, and why root tips are suitable.Open →
• Meiosis, linkage and sex linkageRecall questions on how meiosis generates variation through crossing over and independent assortment, and on loci, linked genes and sex linkage.Open →
• The structure of sperm and egg cellsRecall questions on the acrosome, the flagellum, mitochondria, the zona pellucida and the cortical granules.Open →
• Fertilisation: the acrosome and cortical reactionsRecall questions on what triggers each reaction, and on how polyspermy is prevented.Open →
• Totipotency, pluripotency and sources of stem cellsRecall questions on self-renewal, the potency of embryonic and adult stem cells, and where each is found.Open →
• The ethics and risks of stem cell therapyRecall questions on the arguments over using embryos, induced pluripotent stem cells, and the risks of rejection and tumour formation.Open →
• Differential gene expression and specialisationRecall questions on why cells with the same genome become different, and on the specialised cells produced.Open →
• The lac operonRecall questions on the structural genes, promoter, operator and regulatory gene, and on what happens when lactose is present and absent.Open →
• Epigenetics: DNA methylation and histone modificationRecall questions on how methylation and histone acetylation change gene expression, and on why the changes persist.Open →
• Polygenic inheritance, continuous variation and statisticsRecall questions on polygenic inheritance, multiple alleles and continuous variation, the mean, median, mode, range and standard deviation, the Student’s t-test and Spearman’s rank correlation coefficient, and choosing the right statistical test.Open →

What you need to know

Answer each one before you reveal it.

Take Voice of the Genome further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Totipotent cell vs Pluripotent cell

  Totipotent cell: unspecialised cell able to form every embryonic and extra-embryonic type. Pluripotent cell: unspecialised cell able to form every body-cell type.

• Mitosis vs Meiosis

  Mitosis: division producing genetically identical daughter nuclei. Meiosis: division producing genetically varied haploid nuclei.

• Genotype vs Phenotype

  Genotype: genetic constitution of an organism. Phenotype: observable characteristics produced by genes and environment.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is the fundamental structural unit of all living organisms?

   Model answer

   The cell: every living thing is built from one or more of them.

2. 2

   State four features that are common to all cells, whether prokaryotic or eukaryotic.

   Model answer

   All cells possess a plasma membrane, cytoplasm, ribosomes, and genetic material (DNA).

3. 3

   What structural component surrounds the plasma membrane in prokaryotic cells?

   Model answer

   A cell wall.

4. 4

   What is the function of the capsule found in some prokaryotic cells?

   Model answer

   It acts as a protective layer outside the cell wall.

5. 5

   What are plasmids?

   Model answer

   Small circular DNA molecules found in prokaryotic cells, separate from the main chromosome.

6. 6

   Name the structure that enables locomotion in some prokaryotic cells.

   Model answer

   Flagellum.

What is inside Levo

Six ways to work the same material.

Voice of the Genome revision questions

Is Voice of the Genome examined at AS in Edexcel Biology A?

Yes. It sits in Papers 1, 2 and 3, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.

What does Voice of the Genome cover in Edexcel AS-Level Biology A?

16 subtopics: prokaryotic cells, eukaryotic organelles and their functions, identifying organelles in an electron micrograph, protein secretion, and levels of organisation, microscopy: the graticule, magnification and standard form, the cell cycle and the stages of mitosis, core practical: the root tip squash, meiosis, linkage and sex linkage, the structure of sperm and egg cells, fertilisation: the acrosome and cortical reactions, totipotency, pluripotency and sources of stem cells, the ethics and risks of stem cell therapy, differential gene expression and specialisation, the lac operon, epigenetics: dna methylation and histone modification and polygenic inheritance, continuous variation and statistics. Each one has its own page with questions and model answers.

How is Voice of the Genome organised?

By the Edexcel 9BN0 specification, subtopic by subtopic, so it matches the order you are taught it in.