Lesson 2: Mendelian Genetics Flashcards
alternative form of a gene
allele
contain like genes for any character
Homozygous
contains two kinds of genes for an allelic pair
Heterozygous
appearance or assemblage of characters that are expressed; may change because of interactions with environment and other genes
phenotype
formula to define the phenotypic value of an individual as the consequence of the alleles
P = G + EP = G + E + G x EP = phenotypeG = genotypeE = environment
genetic constitution of an individual; constant
genotype
trait that is expressed in the heterozygote
dominant trait
hidden in the heterozygote
recessive trait
- father of genetics- Developed the fundamental laws of heredity
Gregor Mendel
Gregor Mendel blended the __ vs __
- Concept of Inheritance- Particulate Theory of Inheritance
Mendel chose __ as his subjects as they are easily grown and their pollination is easily controlled. He controlled pollination by manually moving pollen between plants
garden peas (Pisum sativum)
Gregor Mendel developed True-breeding plants by __
self-pollination
produce pollen grains, which contain male gametes in plants
anthers
produce female gametes in plants
ovules
receives pollen
stigma
Process of self-pollination
- Remove anthers from one plant.2. Collect pollen from a different plant.3. Transfer pollen to stigma of the 1st plant (plant without anthers)
Why Mendel Was Successful
- Unbiased* Selected good model organism* Used pure breeds as parents* Large sample size* Quantitative analysis* Controlled experiments* Studied obvious traits
Mendel’s Conclusion: Genes do not __ together. Genes maintain their __ from generation to generation.
- blend - integrity
Mendel’s Conclusion: Peas have __, of each __.
- two alleles- gene
Mendel’s Conclusion: Each gamete contains __. Pairs of alleles segregate during the formation of __
- one allele of each gene- gametes
Mendel’s Conclusion: Males and females contribute __ to the __ of their offspring. When gametes fuse, offspring acquire a total of __—one from each parent
- equally - genotype - two alleles
Mendel’s Conclusion: Some alleles are dominant to others. When a dominant and recessive allele for the same gene is found in the same individual (heterozygous), that individual exhibits the __ phenotype.
- dominant
Alleles occur in pairs and that in the formation of gametes, these segregate so that only one member of a pair goes into a particular gamete. What law?
Law of Segregation
Each parent contributes __ to the progeny. What law?
- equally- Law of Segregation
The __ phenotypic ratio means that the F1 contains the __ alternative forms of the gene or is heterozygous.
- 3:1 - two
involves one (mono) character and different (hybrid) traits.
monohybrid cross
- Genetic problems can be easily solved using a tool – Tool for calculating genetic probabilities
Punnett square
- based on dihybrid crosses where two genes are considered simultaneously- alleles in different gene pairs separate cleanly from each other and randomly combine during gamete formation
Law of Independent Assortment
are made when phenotypes and genotypes composed of 2 independent alleles are analyzed.
Dihybrid crosses
- genes that are on the same chromosome are linked- do not undergo independent assortment
linked genes
Mendelian disorders in humans
- ptosis - achondroplasia- Progeria- polydactyly
known as the drooping of the upper eyelid, and the patient usually presents with the complaint of the defect in vision and cosmesis. It can be congenital or acquired, or it can be neurogenic, myogenic, aponeurotic, mechanical, or traumatic in origin.
ptosis
- a genetic condition affecting a protein in the body called the fibroblast growth factor receptor.- this protein begins to function abnormally, slowing down the growth of bone in the cartilage of the growth plate.
achondroplasia
also known as Hutchinson-Gilford progeria syndrome, is an extremely rare, progressive genetic disorder. It causes children to age rapidly, starting in their first two years of life.
progeria
- From Greek word Thalassa (sea) and haemia (blood)* caused by reduced or absent synthesis of the __ of __* Manifests during 2nd year; causes __, __, __* Requires life-long __
- β-Thallasemia- beta chains; hemoglobin- severe anemia- poor growth- skeletal abnormalities- blood transfusion
- Stabilizing selection against __* Heterozygote superiority* Similar to __/autosomal recessive* Highest prevalence among Greeks (10%); Fil in Canada ( 4%); Taiwan (0.9%)
- β-Thallasemia- malaria- sickle cell anemia
