Topic 11- Genetics and Inheritance Flashcards
What is Mendel’s Model?
- Different versions of genes results in different characters
- Each character an organism inherits one allele per parent
- If the allele differs, the dominant alleles takes over
- Law of segregation: Two alleles separate during gamete formation to form 2 different gametes
Phenotype Vs. Genotype. What are the types of genotypes?
Phenotype: describes the physical component
Genotype: Describes the genetic component.
- homozygous: has the two same alleles
- Heterozygous: made of two different alleles.
- Hemitzygous: males that only have one allele
Name and describe the single gene non mendelian forms of inheritance.
Complete Dominance- Mendel’s model where the phenotype of heterozygous genotypes matches the homozygous dominant phenotype.
Incomplete dominance- Phenotype of heterozygous genotype is a mix of the two homozygous phenotypes
Codominance- Phenotype is affected by the two alleles and separate and distinguishable ways
Describe the phenotypes and genotypes of ABO blood types and how the can be used with each other
A is dominant when combined with O
B is dominant when combined with O.
A and B can only take its own blood type
AB can get blood from anywhere but can only give it to AB
O can give to anyone but can only get it from O
Describe the law of segregation
When gametes are made each gamete receives a random allele.
What did Morgan’s experiment prove?
Proved the existence of x linked traits.
How do you find recessive traits on a pedigree?
Find two matching parents with a different child. The child has to be recessive
Describe the law of independent assortment
The alleles of two different genes get assorted into gametes independently of each other.
What is a dihybrid cross and how do you calculate odds of a trait?
Observing two different genes. Find the probability of finding each separate trait and multiply them by each other.
What are recombinant offspring. What is recombination frequency and what does it tell us?
When the genotype of two dominant dominant traits and a recessive recessive trait is mixed between dominant and recessive.
Recombination frequency is the # of recombinant offspring divided by the total offspring.
If it is less than 50% the genes are on the same chromosome. The close to 50 it gets the farther apart the genes are on the chromosome.
What are the non Mendelian models for multiple genes?
Epistasis: When one gene relies on another to work. One gene can prevent the other from working.
Polygenic: Multiple genes all independently affect the phenotype such as height.
Pleiotropy: One gene has multiple effects. ex. sickle cell
