GContinuedLEC9 Flashcards
How did Mendel identified his second law of inheritance?
By following two characters at the same time.
Crossing parents with 2 different characters produces what?
Dihybrids! They are heterozygous for BOTH characters.
Each pair of alleles sorts independently during gamete formation, this law is called?
The Law of Independant Assortment!
Ex. (Yy)(Rr)FOIL.Each offspring gets a unique mix of their parent’s alleles.
Getting your mom’s curly hair doesn’t mean that you will also get her blue eyes, why not?
Our chromosomes swap genes by crossing over, and sort themselves randomly before dividing at the metaphase plate.
Inheritance patterns are often more complex than those predicted by simple Mendelian genetics. Dominant and recessive alleles don’t “interact”, instead they what?
Synthesize different proteins that produce a particular phenotype.
This occur when the phenotypes of the heterozygote and dominant homozygote are identical.
Complete Dominance!
This occur when phenotype of F1 hybrids is in between the phenotypes of the 2 parents.
Incomplete Dominance!
Are dominant alleles common in the wild?
No!
Ex. Polydactyly (6 fingers) is a rare genetically dominant trait.
Most genes actually exist in (more) than two allelic forms. This occur when 2 dominant alleles affect the phenotype in seperate, distinguishable ways.
Codominance!
Ex. Human blood group AB.
Human characters, like height, vary in the population along a continuum and are called?
Quantitative characters!
Many of these are POLYGENIC, determined by multiple genes
What is continuously variable and polygenic?
Skin Color! 2 parents with similar skin tone can produce offspring with a variety of skin colors.
Another departure from simple Mendelian genetics. When the (phenotype) depends on the ways the (environment) acts on the (genotype). Example?
The sun’s effect on skin color.
