Unit 5 Non-mendelian Genetics Pt 1 Until Chi Square Flashcards
Why do many traits not follow the ratios predicted by mendels laws?
What type of dominance did mendels experiments include?
Complete dominance
What’s complete dominance
Homozygous dominant and heterozygous individuals are
phenotypically the same.
(Ex: H=long hair, h=short hair
HH=long hair Hh=long hair)
What’s incomplete dominance
Neither allele is fully dominant and none of the previous alleles will show.
(EX: red flowers crossed with white flowers will produce pink offspring)
What codominance?
Two alleles that affect phenotype are both expressed
(EX: type AB blood: both A and B are expressed)
What does Multiple alleles mean
Genes that exist in forms with more than two alleles
What’s a sex linked gene
A gene located on either the X or the Y chromosome
What’s a Y linked gene
Genes specifically found on the Y chromosome
What’s a X linked gene
Genes specifically found on the X chromosome
Fathers can pass x linked alleles to their ___ but not their ___
Daughters
Sons
Mothers can pass x linked alleles to their ___
Daughters or sons
What’s happens if an x link trait is due to a recessive allele? Why? What’s term for it?
During development of females most of the X chromosomes in each cell become
____. The ___ cell of a female condenses into a ___ in order to ___ gene dosage in females
Inactive
Inactive
Barr body
Regulate
What is the pedigree pattern of this and why?
What is the pedigree pattern of this and why?
What is the pedigree pattern of this and why?
What’s epistasis and the phenotypic ratio for it
The phenotypic expression of a gene at one locus affects a gene at another locus
9:3:4
What’s polygenic inheritance?
The effect of two or more genes acting on a single phenotype
(EX: height, human skin color)
What is genetic recombination and what’s the parental types and recombinants
An picture example of recombinant example
What are linked genes?
Genes located near each other on the same chromosome that tend to be inherited together
meiosis and random fertilization generate genetic variation in offspring due to ____
What is the relationship between the proximity of linked genes on a chromosome and crossing over?
The closer two linked genes are on a chromosome, the less likely they are to be separated by crossing over.
What happens to linked genes during meiosis?
Linked genes assort together during meiosis.
What law do linked genes violate?
The law of independent assortment.
Image of non recombinant chromosomes
What happens to the probability of a crossing over event as two genes are further apart on the same chromosome?
The probability of a crossing over event increases
This is due to the physical distance between the genes allowing for more opportunities for crossing over.
What is the relationship between gene distance and recombination frequency?
The higher the distance between two genes, the higher the recombination frequency
Recombination frequency is a measure of how often crossing over occurs between genes.
Fill in the blank: The further apart two genes are on the same chromosome, the _______ the probability that a crossing over event will occur between them.
higher
True or False: Closer genes on a chromosome have a higher recombination frequency.
False
Closer genes are less likely to experience crossing over, resulting in a lower recombination frequency.
What is a linkage map?
A genetic map that is based on recombination frequencies
Linkage maps help in understanding the genetic distance between loci on a chromosome.
What are map units in genetics?
The distance between genes
Map units quantify the relative distances between genes based on recombination frequency.
How is one map unit defined?
Equivalent to a 1% recombination frequency
This definition is crucial for understanding genetic linkage and mapping.
What does a 50% recombination frequency indicate?
That the genes are far apart on the same chromosome or on two different chromosomes
A 50% recombination frequency suggests that the genes assort independently.
What do linkage maps express?
The relative distances along chromosomes
These distances help in predicting inheritance patterns.
What does higher recombination frequency indicate?
A higher chance of crossing over between two alleles
This indicates that the alleles are more likely to be separated during meiosis.
How is recombination frequency related to gene distance?
It can be used as a measure of how far apart two genes are on a chromosome
The greater the distance, the higher the likelihood of recombination.
What does a 1% chance of recombination frequency represent?
1 map unit
This unit is also known as a centimorgan (cM) in genetics.
What type of DNA is found in mitochondria and chloroplasts?
Non-Nuclear DNA
Non-nuclear DNA refers to genetic material located outside the nucleus, specifically in organelles like mitochondria and chloroplasts.
How are mitochondria and chloroplasts assorted during cell division?
Randomly assorted to gametes and daughter cells
This random assortment means that the distribution of these organelles is not predetermined.
In animals, how is mitochondrial DNA transmitted?
By the egg, NOT the sperm
This means that only maternal lineage contributes to mitochondrial DNA inheritance.
Is mitochondrial DNA inherited paternally or maternally?
Maternally inherited
This indicates that all mitochondrial DNA in offspring comes from the mother.
In plants , how is mitochondrial and chloroplasts DNA transmitted?
In the ovule NOT the pollen
Both mitochondrial and chloroplast determine traits are ____ inherited
Maternally
