Introduction to Genetics and Evolution

Gene

A hereditary unit of DNA that codes for a protein and determines a trait

DNA

A complex molecule that carries the genetic information of an organism

Chromatin

Condensed DNA tightly coiled around histones

Nucleosome

A structural unit of a chromosome consisting of a length of DNA (147bp) coiled around a core of histones.

Octamer

Consists of two copies of each of the four core histone proteins: H2A, H2B, H3, and H4

Evolution

The change in the characteristics of a species over several generations from ancient to modern times

Model systems (model organisms)

Organisms that adapt well to laboratory situations and findings from experiments on them can apply across a broad range of species.
E.g., white mice, Drosophila fruit fly

Lamarck's Theory of Evolution

Proposed theory that organisms pass on traits they acquire in their lifetime. (Incorrect) i.e. Scars

Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Genetics

The scientific study of heredity

Phenotype vs. Genotype

- Phenotype: expressed physical traits
- Genotype: Genetic make-up

Positive Eugenics

Encouraging the reproduction of those with beneficial traits

Negative eugenics

Discouraging the reproduction of those with undesirable traits

Ploidy of a cell

number of sets of chromosomes in a cell

Allele

Different forms of a gene

Nucleic acids

DNA and RNA (or macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus )

Genomics

study and comparison of genomes within a single species or among different species

natural selection

the process whereby organisms better adapted to their environment (due to specific alleles) tend to survive and produce more offspring

What is the role of mutation in evolution?

The ultimate source of variation in natural populations