Unit 7a Flashcards
Who contributed to the chromosomal theory of inheritance?
Walter Sutton and Theodor Boveri
What did Walter Sutton do
Observed the seperatuon of chromosomes into gametes during meiosis under a microscope
What did Theodor Boveri do?
Observed that proper embryonic development of sea urchins doesnt occur unless chromosomes are present
What did Sutton and Boveri theorize?
Genes are on Chromosomes
What are 4 observations of Sutton
-during meiosis, homolougous chromosome-pairs migrate indenpendently of other chromosome pairs
-the sorting of chromosomes appear to be random
-each parent makes gametes that contain half of their chromosomal complement
-the gametes combine during ferlilization to produce an offspring with the sum of chromosome numbers
What prevented sutton and boveri from presenting this idea
They had mo conclusive evidence to support it
Who help to find evidence for chromosomal inheritance theory?
T.H. Morgan
What did Thomas Morgan Do?
He followed eye colour trait in fruit flies, which is a sex-linked trait
What is TH morgans procedure?
-P-gen: white eyed male x red eyed female= all red eyed offspring
-F1 gen: red eyed offspring were bred from previous generation
-F2 gen: this 50/50 split was determined by sex, and not by simple dominance
Watch this video on Morgans experiment
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What is chromosome theory
-genes are found at specific locations on chromosomes and their behavior during meiosis explains Mendels law of inheritance
What does X-linked mean
-sex-linked trait
-gene is present on the X chromosome
What is dosage compensation
In each female cell, one X chromosomes is always inactivated and folded into a Barr body, causing heterozygous females genetic mosaics
How is sex determine in fruit flies compared to humans
Fruit flies: number of X chromosomes
Humans: presence of a Y chromosome(since there could be multiple X chromosomes
What is Bird sex determination?
Birds are the opposite of fruit flies, meaning that males have two of the same chromosome (Z) while female have ZW
