Term 1

D4.3.1—Anthropogenic causes of climate change 

D4.3.2—Positive feedback cycles in global warming 

D4.3.3—Change from net carbon accumulation to net loss in boreal forests as an example of a tipping point 

D4.3.4—Melting of landfast ice and sea ice as examples of polar habitat change

D4.3.5—Changes in ocean currents altering the timing and extent of nutrient upwelling

D4.3.6—Poleward and upslope range shifts of temperate species

D4.3.7—Threats to coral reefs as an example of potential ecosystem collapse

D4.3.8—Afforestation, forest regeneration and restoration of peat-forming wetlands as approaches to carbon sequestration

D4.3.9—Phenology as research into the timing of biological events 

D4.3.10—Disruption to the synchrony of phenological events by climate change 

D4.3.11—Increases to the number of insect life cycles within a year due to climate change

D4.3.12—Evolution as a consequence of climate change 

A4.2.1—Biodiversity as the variety of life in all its forms, levels and combinations

A4.2.2—Comparisons between current number of species on Earth and past levels of biodiversity 

A4.2.3—Causes of anthropogenic species extinction

A4.2.4—Causes of ecosystem loss

A4.2.5—Evidence for a biodiversity crisis

A4.2.6—Causes of the current biodiversity crisis

A4.2.7—Need for several approaches to conservation of biodiversity

A4.2.8—Selection of evolutionarily distinct and globally endangered species for conservation prioritization in the EDGE of Existence programme

D2.1.1—Generation of new cells in living organisms by cell division

D2.1.2—Cytokinesis as splitting of cytoplasm in a parent cell between daughter cells

D2.1.3—Equal and unequal cytokinesis

D2.1.4—Roles of mitosis and meiosis in eukaryotes

D2.1.5—DNA replication as a prerequisite for both mitosis and meiosis

D2.1.6—Condensation and movement of chromosomes as shared features of mitosis and meiosis

D2.1.7—Phases of mitosis

D2.1.8—Identification of phases of mitosis

D2.1.9—Meiosis as a reduction division

D2.1.10—Down syndrome and non-disjunction

D2.1.11—Meiosis as a source of variation

D2.1.12—Cell proliferation for growth, cell replacement and tissue repair

D2.1.13—Phases of the cell cycle

D2.1.14—Cell growth during interphase

D2.1.15—Control of the cell cycle using cyclins

D2.1.16—Consequences of mutations in genes that control the cell cycle 

D2.1.17—Differences between tumours in rates of cell division and growth and in the capacity for metastasis and invasion of neighbouring tissue

D1.1.1—DNA replication as production of exact copies of DNA with identical base sequences

D1.1.2—Semi-conservative nature of DNA replication and role of complementary base pairing

D1.1.3—Role of helicase and DNA polymerase in DNA replication 

D1.1.4—Polymerase chain reaction and gel electrophoresis as tools for amplifying and separating DNA

D1.1.5—Applications of polymerase chain reaction and gel electrophoresis

D1.1.6—Directionality of DNA polymerases

D1.1.7—Differences between replication on the leading strand and the lagging strand

D1.1.8—Functions of DNA primase, DNA polymerase I, DNA polymerase III and DNA ligase in replication

D1.1.9—DNA proofreading

D1.2.1—Transcription as the synthesis of RNA using a DNA template

D1.2.2—Role of hydrogen bonding and complementary base pairing in transcription

D1.2.3—Stability of DNA templates 

D1.2.4—Transcription as a process required for the expression of genes 

D1.2.5—Translation as the synthesis of polypeptides from mRNA

D1.2.6—Roles of mRNA, ribosomes and tRNA in translation

D1.2.7—Complementary base pairing between tRNA and mRNA

D1.2.8—Features of the genetic code

D1.2.9—Using the genetic code expressed as a table of mRNA codons

D1.2.10—Stepwise movement of the ribosome along mRNA and linkage of amino acids by peptide bonding to the growing polypeptide chain

D1.2.11—Mutations that change protein structure

D1.2.12—Directionality of transcription and translation

D1.2.13—Initiation of transcription at the promoter

D1.2.14—Non-coding sequences in DNA do not code for polypeptides

D1.2.15—Post-transcriptional modification in eukaryotic cells 

D1.2.16—Alternative splicing of exons to produce variants of a protein from a single gene

D1.2.17—Initiation of translation

D1.2.18—Modification of polypeptides into their functional state

D1.2.19—Recycling of amino acids by proteasomes