UNIT 4 BIOLOGY Continuity and Change: Genetics and Evolution

Assessments  SACs Summary report of a genetic cross (practical) DNA technologies (GTAC) Report on evolutionary relationships Presentation on gene technologies EXAMINATION

Introducing genetics  Chromosomes and meiosis  Alleles, phenotypes and test crosses  Linked genes and crossing over  Pedigrees

Structure and function of DNA  Genes  The genetic code – what does it mean?  Molecules involved in building DNA and proteins  Genomics  Gene mutations

How the cell uses DNA  Transcription and translation (building a protein)  Self-replication of DNA  The relationship between the code present on the DNA and the characteristics on the organism

DNA and technology  How do we manipulate DNA?  The tools and techniques required  Electrophoresis  Applications of technology in genetics

Introduction to evolution  Variations in a population  Natural selection as the agent for evolution  Special DNA: mitochondrial

Evolution theory  History of evolution theory  Evidence for evolution  Different types and patterns of evolution

Human evolution  Relationships between modern humans and ancient human-like creatures  “Monkey to man”?  Cultural and technological evolution: how does it impact our biology?

Human intervention in evolution  Disruption of evolution  Technology use  Selective breeding  Reproductive and therapeutic cloning

Today: introducing genes  Where are our genes?  What are genes made of?  What is the history of DNA?

What is genetics?  Genetics is the study of heredity  Animals, plants and micro- organisms are studied E. coli

Chromosomes  Are long thread like structures found in the nucleus  Made of a chemical called DNA  Some DNA is also found in the mitochondria and chloroplasts

Homologous chromosomes  2 copies of each chromosome in each somatic (body) cell  2 copies of each gene in each cell  Humans have 46 chromosomes in each body cell  What is the difference between a male and female? Karyotype of a human male

History  In 1953 Watson and Crick unravelled the structure of DNA  Deoxyribonucleic acid  Double helix  Controversy of how results were obtained

DNA  Deoxyribonucleic acid  Double helix which looks like a twisted ladder  Made up of nucleotides containing a phosphate, sugar and a base

Bases  Specific base pairing  Adenine - Thymine  Guanine - Cytosine  DNA is universal – all living things from bacteria to plants and animals have the same 4 bases

DNA and chromosomes  DNA coils tightly around proteins  Like a twisting piece of string Protein

DNA