UNIT 4 BIOLOGY Continuity and Change: Genetics and Evolution.

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