Genetics - Intro to Genetics

Artificial selection

First development in genetics (10-12k years ago), Middle East domestication of crops and wolves

Hindu writing states that…

Traits are inherited from father & any sibling differences come from mother

Pangenesis

Gemmules pick up traits acquired in a lifetime to pass to kids (Ancient Greeks 520 GC)

Aristotle 350 BC

Both parents contribute traits

Preformationism

Baby is preformed in either the sperm or the egg (1600s)

Germ plasm theory

Only germ cells (not somatic) are inherited, debunked by Weismann’s mice (1800s to today)

Selective breeding

Eugenics laws—involuntary sterilization of imperfect individuals

Gregor Mendel’s…

Pea plants (1865) demonstrated basic heredity, dominant & recessive inheritance

DNA structure

Sugar phosphate backbone, nucleotide rungs of complementary base pairings

How many genomes does each cell have? (besides gametes)

2: one from mom + one from dad

Differentiation

Determines what genes are expressed when, bc every cell in the body has the same DNA

Mendelian Inheritance

Traits are passed from parents to offspring; each parent contributes one copy from each gene pair to the offspring

When are cells haploid?

During meiosis when gene pairs are separated

When are cells diploid?

When the egg & sperm fuse

Polypeptide chain

String of amino acids

Mutations in the DNA sequence will lead to…

A different amino acid chain & incorrect protein folding

Transmission Genetics

Focus on individual; arrangement of genes, gene mapping, heredity, pedigree analysis

Molecular Genetics/Cytogenetics

Focus on the gene + chromosome; replication, gene expression & regulation, karyotypes, recombination gene technology

Population Genetics

Focus on groups of genes in a population; genetic composition of groups, evolution, and gene flow

Improving nutrients of seed oils

By altering fatty acid composition

Delayed ripening of…

Tomatoes

Insect resistance

Hurts insect & not humans

Medicine & society

Gene therapy & disease detection

Embryo splitting

Creates twin/clones (study different environmental components)

Nuclear transfer

Extracting somatic DNA from one cell & transplanting it into the egg of another organism; mosaicism

Increase milk production

Genetically engineering livestock/altering milk composition

Production of human organs in…

Pigs

Model organisms

Share similar genetic qualities to humans, quick reproduction, manageable number of offspring

Germ cells

Gametes (sperm & egg), haploid (23 chromosomes)

Somatic cells

Form rest of body’s tissues & organs (not gametes), diploid (46 chromosomes)

Blending theory

When the genes from your mom and dad mix to create your phenotype (blonde + black hair = brown)