BIOL1003 Lecture Notes - Lecture 1: Woolly Mammoth, Immunochemistry, Pangenesis
BIOL1003: Module 2 - Genetics
Lecture 2 – Forensics, Systematics, Introduction to Genetics
Crop and stock improvement
• Fig selection for size, mass cloning - implemented selection
• Since 11000 years ago - first was peas
Forensics
• Identity/paternal testing
o Based on blood types from 1920s
o Based on proteins from 1940s
o First accepted in court in 1950s
o Based on HLA (immunochemistry) from 1960s
o Based on cutting DNA from 1970s
o Based on amplifying DNA from 1980s
• Cheetahs have very low genetic diversity - same genetic decline as seen wooly mammoths
• Hemophilia a consequence of low genetic diversity - as in royalty
Systematics
• Early systematics was based on similarity
• Modern systematics based on evolutionary history
o Well choses morphological traits can be good
o Genetic features usually better
The chromosome
• It was observed under the first microscopes that all organisms were made of cells
• It was also observed that all cells have black dots in them. This was called the nucleus (it was
just named)
• Nuclei condensed and became darker
• Dividing cells scramble all of their internal bits, then put them together again, starting with the
nucleus – must be important.
• The nucleus breaks up to form dark, easily stainable coloured bodies = chromosomes
• CHROMOSOMES only present during cell division
The gene
• Mendel hypothesized a factor that coveys traits from parent to offspring (1860s)
• Darwin used phrase "pangenesis"
• Shortened to "pan-gene" in 1880: the smallest particle (representing) one hereditary
characteristics
• Gene first used in 1909: fundamental physical and functional unit in heredity
• Found
What is a chromosome?
• It is a condensed form proteins and nucleic acids carrying genetic information, visible only
during cell division
• Where is it when the cell is not dividing
o It is relaxed, spread out in the nucleus and is called chromatin. It is still made of nucleic
acid and proteins, but looks different
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