Mendellian Madness! Father of Genetics

Karyotype

Karyo... what!? Karyotype: set of photographs of chromosomes grouped together in pairs. Often used in genetic screening Allows scientists to determine if there are errors Useful in determining gender

A he or a she?

Why females are smarter...?

SMART

Born 1822 Before chromosomes known Pea plants are what he loved! Self-polinating Sperm cells on flower fertilize egg on same flower True breeding Offspring would be identical to itself egg

Mendel the Austrian Monk

Cross pollination

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trait - specific characteristic.. Ex: height Ex: seed color hybrid - offspring of crosses b/w parents w/ diff traits. monohybrid cross uses a pair of contrasting traits. Ex: yellow/green dihybrid cross involves 2 characters, such as seed color and seed shape.

generation is a group of offspring from a given group of parents. heredity heredity the passing of traits to the next generation:. Scientific study of heredity: genetics genetics. Modern genetics is based on Mendel’s explanations.

Genes!!! Sequence of DNA that codes for a protein thus determines a trait Mom Dad Gene

TT Tt tt Allele AA Aa aa TtTt AaAa Principle of Dominance Some alleles are dominant, some are recessive

Dominant vs. recessive Dominant allele: Shows if there. Masks recessive traits Symbolized by CAPITAL LETTERS Shows up most commonly in a population Why? Recessive allele: Masked by dominant trait Symbolized by lower case letters Less common in pop. Why?

Class Poll: Dominant or recessive?

Which do they show? Laser beam eyes are recessive: Ll Dolphin nose is dominant:dd

Mendel noted…. w/ monohybrid cross yellow:green

y Y Y y YyYy YyYy YyYy YyYy All Yy … all yellow y Y Y y YyYy YyYyYY yy

Geno-Pheno-What? Genotype: Genetic makeup of an organism Phenotype: Physical characteristics of an organism TT Tt tt Tall short

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Mendel’s Ideas Law of Segregation Each adult has two copies of each gene - one from each parent These genes are segregated from each other when gametes are formed TT TT tt tt

Mendel’s Ideas Law of Independent Assortment Genes for more than one trait can segregate independently during the formation of gametes Genes that segregate independently do not influence other genes inheritance Ind. Assortment: helps account for the many genetic variations seen in things

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Dihybrid Cross Whoah … hold that thought…