Non-Mendelian Genetics Flashcards
Many genes come together
and mix
Non-Mendelian Inheritance
Genes from both parents can mix or show up in organisms, causing the inheritance to become uncertain or hard to predict.
Non-Mendelian Inheritance
One gene dominates the other
Mendelian Inheritance
Dominant allele appear
on the organisms while
the recessive allele will
not appear
Mendelian Inheritance
A term that describes the joint role of multiple genes in determining phenotypic variability.
Gene Interactions
This occurs when one gene control one trait, such as in various forms of dominance relationship.
Allelic Interactions
ALLELIC INTERACTIONS
A. Complete dominance
B. Incomplete dominance
C. No dominance
A condition wherein the allele regarded as dominant completely masks the effect of the allele that is recessive.
COMPLETE DOMINANCE
In complete dominance, what is the phenotypic ratio of F2 generation?
3:1
The dominant character expresses itself but not completely.
INCOMPLETE DOMINANCE
In this case, dominance is absent and the progeny does not resemble any of its parents.
INCOMPLETE DOMINANCE
In incomplete dominance, heterozygotes are _____ ____ between the two homozygous types of the parents.
phenotypically intermediate
In incomplete dominance, what is the phenotypic ratio of F2 generation?
1:2:1
What is the spp. that displays incomplete dominance?
4 o’clock plant Mirabilis jalapa
No particular gene is dominant, such as: Lethal Genes and Codominance
NO DOMINANCE
Both the dominant alleles are equally strong & thus expressed in the offspring simultaneously.
Codominance
Heterozygotes exhibit a mixture of the phenotypic characters of both homozygotes instead of a single intermediate expression.
Codominance
These are genes that can cause the death of an organism.
Lethal Genes
Lethal Genes
→ Dominant lethals
→ Recessive lethals
These are the alleles whose presence is
required in one copy in an entity for them to turn fatal.
Dominant lethals
Example for Dominant lethals
Huntington’s disease
Those that are lethal when in homozygous
recessive condition and effects of recessive genes are sufficiently drastic to kill the bearers of certain genotypes.
Reccesive lethals
A process of how a seed receives genetic information from its parent trees.
Inheritance
Why did Mendel choose pea plant in his experiment in 1857?
-Easy to grow and req. little space.
-Inexpensive
-Self-fertilized
-Cross-pollinated
Traits studied by Mendel.
Seed Shape
Seed color
Flower color
Pod shape
Pod color
Refers to the first individuals that are crossed in a breeding experiment.
Parental Generation
A cross that involves one pair of contrasting traits.
Monohybrid cross
This cross produces the First Filial Generation.
Monohybrid Cross
The offsrings of the two cross-pollinated P generation.
First Filial Generation
In the third experiment, mendel allowed the F1 generation to ___ ____. These produces the ____ _______.
Self-pollinate, F2 generation.
A diagram that predicts the outcome of a genetic cross by considering all possible combinations of gametes in the cross
Punnett Square
Who invented Punnett square?
Reginald C. Punnett
different forms of genes for a single trait
Alleles
gene that is expressed only in the homozygous state
Recessive
MENDEL’S POSTULATES & LAWS OF INHERITANCE
- Principle of Paired Factors
- Principle of Dominance
- Law of Segregation
- Law of Independent Assortment
It says that, genetic characters are controlled by unit factors that exist in pairs in individual organisms.
PRINCIPLE OF PAIRED FACTORS
When two different alleles occur together, one of them may be completely expressed, while the other may have no observable effect on the organism’s appearance.
PRINCIPLE OF DOMINANCE
“During the formation of gamete, each gene
separates from each other so that each gamete carries only one allele for
each gene.”
LAW OF SEGRATION
It states that genes do not influence each other with regard to the sorting of alleles
into gametes: every possible combination
of alleles for every gene is equally likely to
occur.
LAW OF INDEPENDENT ASSORTMENT
- The independent assortment of genes can be illustrated by the ____ ____/
dihybrid cross
a cross between two individuals with two observed traits
dihybrid cross
It is a flower with all of the floral whorls present (calyx, corolla, stamens, and pistil)
Complete
It is the removal of immature male structure to prevent self-pollination or unwanted cross pollination
Emasculation
Where the same trait is expressed generation after generation
True Breeding
Typical phenotypic ratio for a Mendelian dihybrid cross is ____________
9:3:3:1
