genetics Flashcards
Blending inheritance
The historical perspective on how offspring got their traits where the offspring gets half of each parents phenotype
This is false
self-pollination:
When a plant reproduces by fertilising its own eggs
true-breeding:
Plants that, when self pollinating, maintain the same phenotypic expression
Testcross:
A Cross between a organism of an unknown genotype with a organism with know genotype
Monohybrid:
A cross that changes only one of the traits of the organism
Dihybrid:
A cross resulting in the exchange of two separate alleles
Segregation (Mendel’s Principle of Segregation):
The principal Mendel came up with stating that alleles independently separate during gamete formation and join randomly upon fertilization
Homozygous:
The term to describe when a diploid has two of the same allele variations of the same gene
Heterozygous:
The term to describe when a diploid had two separate allele variations of the same gene
Independent assortment (Mendel’s Principle of Independent Assortment):
It states that the allele of one gene that has no effect of the allele received of a second gene
Incomplete dominance:
Happens when the recessive alleles can be seen to some extent in the phenotype of a heterozygous organism.
Codominance:
When there are no dominant/ recessive genes. Instead the alleles are expressed in equal proportion
multiple alleles:
The idea that there are possibly more than two variations of each allele
Epistasis:
When the presence of one allele masks or inhibits the expression of a different allele.
Polygenic inheritance:
When multiple genes contribute to a specific character. An example is things like human height and mass.
Pleiotropy:
When a gene affects more than one trait. Basically the opposite if polygenic inheritance. An example of this is sickle cell disease.
Sickle cell anemia
A recessive allele that causes red blood cells to collapse when they enter the tissue capillaries
Sickle cells are destroyed by your body resulting in anemia.
Describe and compare the genotypes of P, F1, and F2 generations given a Mendelian
monohybrid or dihybrid cross scenario.
P- The parental generation
F1- The first generation of crosses
F2- The second generation of crosses
Explain how a Punnett Square is related to probabilities, and describe what different
regions of a Punnett Square represent.
A punnett square breaks down the possible results so they can easily be put into ratios and frequencies.
Explain how the environment can contribute to a phenotype, using an example
Organisms have to be able to adapt to their environment as much as possible. Epigenetics is the study of how phenotypes change in different environments like the mylination of neurons the more they are used.
