Genetics Flashcards
Ploidy
Means count. As in chromosome count
Diploid has how many chromosomes?
46
Gamete
23 chromosomes
Haploid state
What is “XX and XY” ?
Sex characteristics
Do XXX or triple X female usually have problems?
No
Do XYY has problems?
Nope just male.
Karyotype
Systematic display of metaphase chromosomes.
Aneuploidy
Without true count
Genes
Units of hereditary information
Have physical location on DNA, which is called its locus.
Locus
This is the location on DNA of a specific gene
Alleles
Pairs of contrasting genes
Dominant
The expressed gene
Recessive
Only expressed in the absence of a dominant trait
Genotype
What you are genetically
Phenotype
What you look like
Homozygous
Same
TT or tt
Heterozygous
Different
Tt
Punets Square
Used to determine the probably of a cross between different genes
F1 generation
Monohybrid cross = different in only one trait
The F1 generation is ___________ generation.
Filial
Monohybrid cross
A cross between individuals differing in only one trait
What are the expected phenotypic and genotypic ratios of a cross between two heterozygous tall and dwarf pea plants (Tt x Tt)?
3: 1 (phenotypic)
1: 2:1 (genotypic)
Incomplete dominance (co dominance)
An inheritance pattern in which neither allele is dominant over the other, that is where the heterozygote is intermediate in phenotypic character
Why are autosomal dominant genetic disorders so uncommon?
If you have the disease you are less likely to grow and reproduce so eventually the gene is dropped out over time
Dihybrid cross
Deferring in two traits
Dominant traits (examples)
Huntington’s disease
Huntington’s Disease, why is it still around?
Not noticed until around 40’s and most have reproduced by then therefore it is still around. Woody Gutrie had this.
