Mendlian Genetics Flashcards
The female and male part of the plants are called:
Female: Carpel
Male: Stamen
Gregors 2 laws
Law of Segregation
Law of independent assortment
Law of Segregation states: 4
Each individual has 2 factors for each trait
The factors segregate during the formation of the gametes
Each gamete contains only 1 factor from each pair of factors
Fertilization gives each new individual 2 factors for each trait
State law of Segregation in easy terms
Alleles segregate randomly into gamates
The physical location of a gene is called
Locus
What is the difference between genotype and phenotype
Genotype is represented by TT or tt or any combination
Phenotype is the physical appearance
Dihybrid cross
Cross between parents that differ in 2 traits
Law of independent assortment in easy language
The alleles a gamate recieves for one gene doesn’t influence the allele recieved by another gene
A dihybrid cross gives the ratio of 9:3:3:1
What do these numbers represent
9: Two dominate phenotypes together
3: Dominate phenotype with a hidden recessive
1: Double recessive phenotype
Cross between an individual with a dominant phenotype and an individual with a recessive phenotype to determine whether the dominant individual is homozygous or heterozygous
Testcross
Autosomal Recessive Means:
Give an example
Needs to disease genes to Express the Disease
Cystic Fibrosis
Autosomal Dominate Means:
Example
Needs only 1 disease gene to Express Disease
Huntington’s disease
A carrier of an Autosomal Recessive disease is what?
Someone who carries only 1 copy of the diseased gene
Therefore, they don’t have the disease but can pass it on to off sping
A _____ shows the pattern of inheritance for a particular condition
Pedigree
Cystic fibrosis: Define, causes
Lethal generic disorder which thickens mucus in the Lungs and Pancreas;
The thick mucus in the Pancreas stops digestive enzymes from being released
What physiologically causes the symptoms of cystic fibrosis
Why does this cause the symptoms of Cystic Fibrosis
Defective Chloride Ion Channel
When Chloride can’t pass neither can sodium, hence water can’t follow, causing the mucus to be thick
Is cystic fibrosis autosomal Recessive or Dominate
Recessive
Phenylketonuria: Define
What do these people lack and what is the effect of this
Autosomal Recessive metabolic disorder affecting nervous system development
Lacking enzyme needed to metabolize amino acids phenylalanine
Causes sever brain and nervous system problems
3 autosomal dominate disorders
Osteogenisis imperfecta
Huntington’s disease
Hereditary Sperocytosis
Define Huntington’s Disease:
How is it contracted
What happens to the body during this
Autosomal Dominate Disorder
Neurological Disorder leading to the progressive degeneration of brain cells
The cause of the degeneration of brain cells is: Mutation on chromosome 4 which causes large clumps of Glutamines to form inside of neurons, Attracting other proteins as well
What is Hereditary Spherocytosis
Autosomal Dominate genetic blood disorder that causes Red Blood Cells to become Spherical rather than disc shapped. Causing them to rupture easier
Inheritance pattern in which both alleles of a gene are equally expressed in a hetrozygote
Codominamce
Incomplete Dominance
Example
How does it differ from the blending theory of inheritance
Inheritance pattern in which offspring has an intermediate phenotype
Red flowers and white flowers = Pink flowers
Because the offspring still has the original alleles which will be expressed in future generations
Dominate alleles that are not always or partially expressed
Incomplete Penetrance
Inheritance pattern in which one gene affects many phenotypic characteristics of the individual
Pleiotropy
Pattern of genetic inheritance where 2 or more genes interact to control a phenotype.
Associated with the metabolic pathway
Epistatic interaction
Pattern of inheritance in which a trait is controlled by several alliels
Polygenic inheritance
Occurs when a trait is governed by 2 or more sets of allels
Polygenic Inheritance
Genetic traits that are under the influence of both the environment and multiple genes (polygenes)
Give human examples
Multifactorial traits
Cleft lip/ palate some cancers
Possessing only 1 allele for a gene in a diploid organism
Give an example of when this occurs
Hemizygous
males are hemizygous for genes on the X chromosome
Explain how a trait may be both polygenic and multifactorial
Multifactorial traits are controlled by polygenes that are subject to environmental influences
A heterozygous plant and another heterozygous plant crossing is called
Monohybrid cross
Individuals have 2 factors for each trait (the genotype) and the factors segregate with equal probability into the gamates.
This is the basic description of…
Law of Segregation
Members of 1 pair of factors separate independently of those of another pair. Therefore, all possible combinations of parental factors can occur in the gamates
Law of independent assortment
An individual must possess 2 copies of the recessive allele to express the trait
Autosomal Recessive
Individuals who are Hetrozygous for an autosomal Recessive disease are called…
Carriers
Marfan syndrome and sickle cell disease are examples of…
Pleiotrophy
Skin color and eye color are examples of…
Polygenic traits
These are 2 or more genes that determine if a phenotype will be expressed
A gene for total baldness is ______ to the gene for hair color
The gene for hair color is ______ to the gene for baldness
Epistatic genes
Epistatic
Hypostatic
Example of Codominance
Type AB blood, when both dominate alleles are expressed equally
Give examples of polygenic genes
Hair and skin color
What is the difference between polygenic and epistatic
Polygenic is several genes working together to produce a phenotype
Epistatic is when one gene affects the phenotype of another gene
Compare and contrast incomplete penetrance and incomplete Dominance
Incomplete penetrance is when an individual with a genotype doesn’t express this in the phenotype
Incomplete Dominance is when the dominant allele mixes its phenotype with the recessive allele
The ______ the penetrance the less likely you are to express it
Less
A monohybrid cross will produce which ratio
3:1
What will happen to the recessive trait in a monohybrid cross in the F¹ generation in the Phenotype
What will happen in the F²
F¹ will be hidden from the phenotype
F² will be seen in as a 3:1 in the phenotype
Which Mendelian law is expressed in a monohybrid cross?
Law of Segregation
What is the product rule and how does it apply to Punnet squares?
We have to multiple the chances of independent events to recieve an awnser
Exp. When a parent contributes an Allele it has a 1/2 chance of contributing each of 2 alleles
AA = 1/2 x 1/2 = 1/4
Or
Aa = 1/2 x 1/2 = 1/4
Is the product rule used for Genotypes or Phenotypes
Genotypes
How do we calculate the results for Phenotypes?
The Sum Rule (Addition)
Probabilidad
Exp. #1
AA = 1/2 × 1/2 = 1/4 What is this rule and what is it determining
Exp. #2.
AA = 1/2 × 1/2 = 1/4 Aa = 1/2 × 1/2 = 1/4 aA = 1/2 × 1/2 = 1/4 aa = 1/2 × 1/2 = 1/4
1/4 + 1/4 + 1/4 = 3/4
Product rule and Genotype
Sum rule and Penotype
What are the probability results for a Mono and Dihybrid cross
3: 1
9: 3:3:1
What is the crosstest ratio for a hetrozygous and homozygous recessive, WHY?
Why does cross test use homozygous recessive and not dominate
1:1, because the dominant will be expressed when given and so will be recessive and combined with a recessive
If a homozygous dominant was used: you wouldn’t know if the test subject was hetro or homozygous. Due to all the phenotype being dominant
What is the expected phenotype ratio for a 2 trait cross test Hetrozygous LlGg and recessive llgg
1:1:1:1
What is an autosome
Any chromosomes other than an X or a Y
A somatic/ body chromosome
What does A_ mean on a pedigree
One genotype is unknown
This law states that in Meiosis allels get put into gamates evenly. One allele for each trait for each gamate
Segregation
When many genes control 1 trait
Polygenic
When 1 gene controls many traits
Pleiotropic
This type of gene expression is characterized by an intermediate phenotype.
Red + White snapdragons = Pink
Incomplete Dominance
When both of the dominate genotypes are expressed. As in blood types
Co Dominance
