IP Biology Genetics: From Mendelian Inheritance to Molecular Genetics

Genetics in IP Biology spans a wide range — from Gregor Mendel's pea plant experiments to modern genetic engineering techniques. Understanding genetics deeply not only helps with IP Biology but also lays the foundation for H2 Biology at JC. Our tutors at Sophia Education teach genetics using a progressive framework that builds understanding step by step.

Mendelian Genetics — The Foundation

Mendel's laws: (1) Law of Segregation — alleles separate during gamete formation; (2) Law of Independent Assortment — genes on different chromosomes assort independently. Master Punnett squares for monohybrid and dihybrid crosses, and understand the difference between dominant, recessive, codominant, and incomplete dominance.

Beyond Mendel: Complex Inheritance Patterns

• ✓Sex-linked inheritance — genes on X chromosome (e.g., colour blindness, haemophilia)
• ✓Codominance — both alleles expressed equally (e.g., ABO blood groups)
• ✓Incomplete dominance — intermediate phenotype in heterozygotes
• ✓Multiple alleles — more than two alleles for a gene in a population
• ✓Polygenic inheritance — multiple genes controlling one trait (e.g., skin colour)

Molecular Genetics — DNA to Protein

The central dogma: DNA → (transcription) → mRNA → (translation) → Protein. Know the details of each step: DNA replication (semi-conservative, DNA polymerase, leading and lagging strands), transcription (RNA polymerase, template strand, mRNA), and translation (ribosomes, tRNA, codons, anticodons).