Ch. 14.1-14.2 Flashcards
Thomas hunt Morgan
Traced specific genes to specific chromosomes
Worked with flies aka drosophila
Chromosome theory of inheritance
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Why are flies good to work with
They have a short generation time
Only 4 total chromosomes (3 autosomes)
Small
Wild Type
The normal phenotype
In the F2 generation of flies only the males had white eyes why?
The trait is linked to the sex chromosome
The Y chromosome
only in males
Does not have traits on it therefore does not impact the passing of traits
Not homologous with the X
Mutant type
The phenotype that’s not the wild type the uncommon one
Where do guys inherit the sex linked genes from
Their mother because they get the Y from their dad and it has no genes
Why are males more likely to inherit a sex linked gene
Males only need to inherit 1 mutant gene from their mother to express it but females need to inherit one from each parent aka the father must have it and show it and the mother can either have it or be a carrier
A recessive alleles significance
A recessive allele is either a malfunctioning protein or complete lack of one. This means of you are heterozygous your body still codes for working protein but only on one allele and that protein is expressed. But if your homozygous recessive then your body expresses the malfunctioning protein since its the only one there.
Why is inbreeding bad
It’s uncommon for two random people to both be carriers but if 2 people with similar ancestry mate the recessive gene is more likely to be present
Amniocentesis
Genetic test to a fetus to test for abnormalities
Nondisjunction
When the chromosomes don’t separate during meiosis
Can occur in meiosis 1 and 1
Aneuploidy
An abnormal chromosome number after nondisjunction
Trisomic
Cells have 3 copy’s of a particular chromosome n+1
