Unit 2: How does inheritance impact on diversity?
10 dot points across 2 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.
How is inheritance explained?
- chromosome structure and organisation, including the role of histone proteins, sex chromosomes and autosomes, homologous pairs and karyotypes as a visual representation of chromosomes used to identify chromosomal abnormalities
A focused answer to the VCE Biology Unit 2 dot point on chromosomes and karyotypes. Covers chromosome structure (DNA wound on histones into chromatin), the difference between autosomes and sex chromosomes, homologous pairs, and the use of karyotypes to diagnose chromosomal abnormalities such as Down syndrome.
9 min answer → - the distinction between genes, alleles and a genome, and the use of pedigrees, Punnett squares and other tools to predict inheritance
A focused answer to the VCE Biology Unit 2 dot point on genes, alleles and the genome. Covers the molecular definition of a gene, the difference between an allele and a gene, the meaning of genome, locus, genotype and phenotype, and how these terms relate to inheritance.
7 min answer → - predicted genetic outcomes for two genes that are either linked or assort independently (unlinked)
A focused answer to the VCE Biology Unit 2 dot point on linked and unlinked genes. Covers the 9:3:3:1 ratio of a dihybrid cross with independent assortment (unlinked), how linkage modifies the ratio by reducing recombinant gametes, and how crossing over generates a small fraction of recombinants in linked genes.
9 min answer → - the production of haploid gametes from diploid cells by meiosis, including the significance of crossing over of chromatids in prophase I and independent assortment of homologous chromosomes in metaphase I for the generation of genetic diversity
A focused answer to the VCE Biology Unit 2 dot point on meiosis. Covers the two meiotic divisions (reduction and equational), the formation of haploid gametes from diploid cells, and the two main sources of genetic variation: crossing over in prophase I and independent assortment in metaphase I.
10 min answer → - models of inheritance that explain phenotype expression, including dominant and recessive autosomal patterns, codominance, incomplete dominance, multiple alleles and sex-linked genes, using Punnett squares to predict outcomes
A focused answer to the VCE Biology Unit 2 dot point on inheritance models. Covers autosomal dominant/recessive inheritance, codominance (ABO blood, MN), incomplete dominance (snapdragon colour), multiple alleles, and sex-linked (X-linked) inheritance such as haemophilia and red-green colour blindness.
11 min answer → - predicted genetic outcomes of a monohybrid cross and a monohybrid test cross
A focused answer to the VCE Biology Unit 2 dot point on monohybrid and test crosses. Covers the 3:1 phenotype ratio of a heterozygote cross, the 1:1 ratio of a test cross with a recessive homozygote, and how a test cross is used to determine the unknown genotype of an organism showing the dominant phenotype.
7 min answer → - pedigree charts and patterns of inheritance, including autosomal dominant, autosomal recessive and X-linked inheritance
A focused answer to the VCE Biology Unit 2 dot point on pedigree analysis. Covers pedigree symbols, how to identify autosomal dominant, autosomal recessive and X-linked recessive inheritance patterns from a family tree, and how to deduce genotypes and calculate probabilities.
9 min answer →
How do inherited adaptations impact on diversity?
- ways of manipulating DNA, including the use of polymerase chain reaction (PCR) to amplify DNA and gel electrophoresis to separate DNA fragments, with reference to DNA profiling
A focused answer to the VCE Biology Unit 2 dot point on DNA manipulation. Covers the polymerase chain reaction (PCR) for amplifying DNA (denaturation, annealing, extension cycles, primers, Taq polymerase), gel electrophoresis for separating fragments by size, and how the two combine in DNA profiling.
9 min answer → - relationships between genes, the environment and the regulation of genes in producing variation in phenotype, including the role of epigenetic factors
A focused answer to the VCE Biology Unit 2 dot point on phenotypic variation. Covers how the same genotype can produce different phenotypes in different environments, the mechanisms of epigenetic regulation (DNA methylation and histone modification), and worked examples (Arctic foxes, Dutch Hunger Winter, identical twins).
9 min answer → - biological consequences, and ethical, social and legal implications, of the use of reproductive cloning technologies, and of genetic screening for inherited conditions
A focused answer to the VCE Biology Unit 2 dot point on reproductive cloning and genetic screening. Covers somatic cell nuclear transfer (Dolly), the biological limitations and ethical issues of cloning, and the methods, uses and ethical considerations of pre-natal, newborn and carrier genetic screening.
9 min answer →