Module 5: Heredity
12 dot points across 5 inquiry questions, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.
Inquiry Question 1: How does reproduction ensure the continuity of a species?
How reproduction ensures species continuity. Asexual methods (binary fission, budding, vegetative propagation, spores), sexual reproduction across animals, plants, fungi, bacteria and protists, the advantages and disadvantages of each, and how variation versus genetic uniformity links to survival.
Mammalian reproduction. Fertilisation of the egg by sperm to form a zygote, cleavage and blastocyst implantation, the menstrual-cycle context (FSH, LH), hCG maintaining the corpus luteum, progesterone and oestrogen maintaining the endometrium and pregnancy, the placenta, and birth driven by oxytocin positive feedback.
Manipulating reproduction in agriculture: artificial insemination and pollination, hormone-induced ovulation, multiple embryo transfer and superovulation, and cloning by somatic cell nuclear transfer, plus how to evaluate their benefits against costs like reduced genetic diversity.
Inquiry Question 2: How important is it for genetic material to be replicated exactly?
Meiosis. The two divisions, crossing over and independent assortment as sources of genetic variation, comparison with mitosis, and how gamete formation maintains chromosome number across generations.
DNA replication. The semi-conservative model, the enzymes (helicase, primase, DNA polymerase, ligase), leading and lagging strands, how mitosis and meiosis differ, and how accurate replication maintains continuity of species, with worked HSC exam examples.
Inquiry Question 3: How does genetic information flow from DNA to functional proteins?
Protein synthesis. Transcription in the nucleus (DNA to mRNA), translation at the ribosome (mRNA to polypeptide), the roles of mRNA, tRNA, rRNA, the codon-anticodon match, and the standard worked exam example.
DNA structure. The double helix, the sugar-phosphate backbone, the four bases and the A-T/G-C base pairing rules, the historical contributions of Watson, Crick, Franklin (Photograph 51) and Wilkins, the forms DNA takes in eukaryotes vs prokaryotes, and worked HSC past exam questions.
Inquiry Question 4: How can the genetic similarities and differences within and between species be compared?
Mendelian inheritance. Mendel's laws, dominant vs recessive alleles, Punnett squares step by step, monohybrid and dihybrid crosses, the standard 3:1 and 9:3:3:1 ratios, and worked HSC past exam questions.
Non-Mendelian inheritance. The difference between codominance and incomplete dominance, multiple alleles using ABO blood groups as the worked example, and the standard Punnett squares with worked HSC past exam questions.
Sex-linked (X-linked) inheritance. Why X-linked recessive disorders affect males more than females, the standard worked Punnett squares for carrier mothers, named examples (haemophilia, colour blindness, Duchenne muscular dystrophy), the criss-cross pedigree pattern, and worked HSC past exam questions.
Inquiry Question 5: Can population genetics be used to determine inheritance patterns in a population?
Technologies that reveal inheritance patterns in a population: DNA sequencing (Sanger chain-termination and next-generation) versus DNA profiling (PCR, short tandem repeats and gel electrophoresis), how to read a gel, and applications in forensics, paternity, conservation and disease-allele tracking.
Using large-scale collaborative data to find trends in population genetics: allele and genotype frequencies in a gene pool, why pooled data matters, and examples from the 1000 Genomes Project, conservation genetics, disease-allele tracking and human evolution.