Unit 4: How does life change and respond to challenges over time?
11 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.
How are species related over time?
- evidence for biological evolution from palaeontology (fossil record, transitional fossils), biogeography, comparative anatomy (homologous and analogous structures, vestigial organs) and molecular biology (DNA, protein sequence comparisons, molecular clocks)
A focused answer to the VCE Biology Unit 4 dot point on evidence for evolution. Covers the fossil record and transitional fossils, biogeography and continental drift, comparative anatomy (homologous, analogous, vestigial structures), and molecular evidence including DNA and protein sequence comparisons and molecular clocks.
12 min answer → - the contributions of Charles Darwin and Alfred Russel Wallace to the theory of evolution by natural selection; selection pressures, variation, differential reproductive success, fitness, adaptation, and the change in allele frequency over time
A focused answer to the VCE Biology Unit 4 dot point on natural selection. Covers the contributions of Darwin and Wallace, the four conditions for natural selection (variation, heritability, selection pressure, differential reproductive success), fitness and adaptation, and how allele frequency changes over time in a population.
12 min answer → - the types of gene and chromosomal mutations (point, frameshift, block; substitution, insertion, deletion, inversion, translocation, duplication, non-disjunction), causes of mutation (errors in DNA replication, mutagens) and the consequences of mutations on the gene product
A focused answer to the VCE Biology Unit 4 dot point on mutation types. Covers point mutations (silent, missense, nonsense), frameshift mutations (insertions and deletions), block mutations and chromosomal aberrations (inversion, translocation, duplication, non-disjunction), the causes of mutation, and how each type affects the protein product.
11 min answer → - the sources of genetic diversity within a sexually reproducing population, including independent assortment of chromosomes, crossing over during meiosis, random fertilisation, and the role of mutation as the original source of variation
A focused answer to the VCE Biology Unit 4 dot point on sources of genetic diversity in sexually reproducing populations. Covers independent assortment in metaphase I, crossing over in prophase I, random fertilisation, and the contribution of mutation as the ultimate source of new alleles.
11 min answer → - the major trends in hominin evolution, including bipedalism, brain size, tool use and dentition; Australopithecus and Homo species; and the out-of-Africa hypothesis for the spread of Homo sapiens
A focused answer to the VCE Biology Unit 4 dot point on human evolution. Covers the major trends in hominin evolution (bipedalism, brain size, tool use, dentition), key species from Australopithecus afarensis to Homo sapiens, and the out-of-Africa hypothesis for the global spread of modern humans.
13 min answer → - speciation, including allopatric and sympatric speciation, the role of reproductive isolating mechanisms (prezygotic and postzygotic), and the biological species concept
A focused answer to the VCE Biology Unit 4 dot point on speciation. Covers the biological species concept, allopatric and sympatric speciation, the role of geographical and reproductive isolation, and prezygotic and postzygotic reproductive isolating mechanisms with examples.
11 min answer →
How do organisms respond to pathogens?
- the innate immune response, including physical, chemical and microbiological barriers and the inflammatory response; and the adaptive immune response, including the roles of B cells, T cells (helper and cytotoxic), antibodies, antigens, and immunological memory
A focused answer to the VCE Biology Unit 4 dot point on the immune system. Covers the innate immune response (physical, chemical and microbiological barriers, inflammation, phagocytosis) and the adaptive response (antigen presentation, helper and cytotoxic T cells, B cells, antibodies, memory cells), with the distinction between humoral and cell-mediated immunity.
13 min answer → - the major groups of pathogens (bacteria, viruses, protozoa, fungi, prions) and the management of disease, including vaccination (active and passive, herd immunity), antibiotics, antivirals, and the emergence of antibiotic resistance
A focused answer to the VCE Biology Unit 4 dot point on pathogens and disease management. Covers the structure and reproduction of bacteria, viruses, protozoa, fungi and prions; how vaccines produce active immunity and herd immunity; the role and limits of antibiotics and antivirals; and the emergence of antibiotic resistance.
13 min answer →