Notes

Mendelian inheritance
Early theories of inheritance:
Blending hypothesis (still around today):
hereditary determinants from parents blend together in the offspring
Ex. white sheep + black sheep = gray sheep (carl naegeli liked this)
Acquired characteristics hypothesis:
Traits present in parents are modified through use and then passed to offspring
Ex. adult giraffes stretch necks for food → longer neck passed to offspring (darwin liked this). Survivability
Gregor mendel: 19th century monk
asked : why do offspring resemble their parents, and how does the transmission of traits occur?
Heredity - transmission of traits from parents to offspring
Trait - any measurable characteristic of an individual (ex. Hair color, skin color, length of my arms, amount of enzyme in my cells)
Not the amount of pain, love someone experiences (these are subjective).
Specific versions of traits are phenotypes. A trait is skin color. Phenotype of skin color is light, dark, brown skin.
Genetics focuses on inheritance of traits. Uses model organisms cause they tend to apply well to other things
Mendel did experiments on garden peas because:
Easy, inexpesive, short reproductive cycle, controllable, large number of seeds, traits were easily recognizable
Pea plant fertilizes themselves when they self pollinate. (sex with self, pollen from self)
Anthers (male) - flower part produce male gametes on tips of stamen
Egg cells found in the ovule of the ovary in the females style. Sticky stigma
Mendel can prevent this by removing the male reproductive organs containing pollen from each flower. He used this pollen to fertilize female reproductive organs of different plants. Thus performing cross-pollination. (i have to make sure i can control these matings so the pea plants dont have sex with themselves. He forced the pea plants to breed with others)
Bees would have been pollinators (but mendel did not use the pollinators in this case)

Mendel only worked with dichotomous outcomes, he studied either round or wrinkled pea plants. Either green or yellow. These were two distinct phenotypes he studied. Dichotomous outcomes were critical to his success and reliable experiment
Based on your genetic makeup you could have differences in how you can shape your tongue, taste cilantro,
Mendel started crosses with True breeding parents. Aka pure-lines.
True breeding plants will always produce the same outcome when it breeds with itself. this is called Homozygocity.

Mate two true breeding parents with different phenotypes (green x yellow), offsprings are called hybrids. They are guaranteed to get genetic info from each parent because they forced cross pollination. Guaranteed one of the parents will contribute green and one will contribute yellow.
Hybridization studies: producing hybrids
Adult plants in cross were the parental generation.
First generation offspring F1 = first filial generation
Mendel crossed pure round and pure wrinkled,,, all F1 offspring made round peas? Wrinkled disappeared. What happened?