Mendelian Genetics Flashcards
Difference between character and trait
Character - observable or specific inheritable features of an organism
Trait - variations of character influenced by genetic and environmental factors
It is an alternative form of a gene
Allele
It contains like gene for any character
Homozygous
It contains two kinds of genes for an allelelic pair
Heterozygous
- appearance or assemblage of characters that are expressed
- may change because of interactions with environment and other genes
Phenotype
Phenotype formula
P = G + E + (G x E)
It is genetic constitution of an individual; constant
Genotype
Trait that is express in the heterozygous
Dominant
Hidden in the heterozygous
Recessive
Father of Genetics
Gregor Mendel
Gregore Mendel developed the _____ ___ of ____
Fundamental Laws of Heredity
What plant did Mendel chose as his subjects?
Graden peas (Pisum sativum)
Garden peas are easily ___ and their ____ is easily ______
- grown
- pollination
- controlled
He controlled pollination by ____ ____ ____ between plants
manually moving pollen
Mendel developed _______ plants by _________
- True-breeding
- self-pollination
It is a form of pollination in which pollen from the same plant arrives at the stigma of a flower or at the ovule
Self-pollination
It receives pollen
Stigma
It produces pollen grains, which contain male gametes
Anthers
It produces female gametes, which contains egg cells
Ovules
Male and Female parts
Anthers and Pistil
This happen when one female gamete unites with two male gametes
Double Fertilization
It is the proccess of applying pollen from one flower to the pistils of another flower
Cross-pollination
Cross-pollination
- Remove anthers from one plant
- Collect pollen from a different plant
- Transfer pollen to stigma of the 1st plant (plant without anthers)
It is a kind of crossing strategy, which means to make crosses between a pair of parents (A and B) by using them in turn as female parent and male parent to obtain two reciprocal crosses of A×B and B×A
Reciprocal cross
Pollen from round-seeded parent to stigma of wrinkled-seeded parent
First Half of Reciprocal Cross
Pollen from wrinkled-seeded parent to stigma of round-seeded parent
Second Half of Reciprocal Cross
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 Conclusions
- Genes do not blend together
- Peas have two versions, or alleles, of each gene
- Each gamete contains one allele of each gene
- Males and females contribute equally to the genotype of their offspring
- Some alleles are dominant to others
Alleles segregate into separate gametes
Law of Segregation
Each parent contributes equally to the ____ and the ___ phenotypic ratio means that the F1 contains the ___ alternative forms of the gene (alleles) or is heterozygous
- progeny
- 3:1
- two
It involves one (mono) character and different (hybrid) traits
Monohybrid cross
It is a 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
It is made when phenotypes and genotypes composed of 2 independent alleles are analyzed
Dihybrid crosses
Mendelian Disorders in Humans
- Ptosis
- Progeria
- Achondroplasia
- Polydactyly
- Albinism
- the drooping of the upper eyelid
- can be congenital or acquired, or it can be neurogenic, myogenic, aponeurotic, mechanical, or traumatic in origin
Ptosis
- also known as Hutchinson-Gilford progeria syndrome
- an extremely rare, progressive genetic disorder
- it causes children to age rapidly, starting in their first two years of life
Progeria
- a genetic condition affecting a protein in the body called the fibroblast growth factor receptor
- protein begins to function abnormally, slowing down the growth of bone in the cartilage of the growth plate
Achondroplasia
- a condition in which a baby is born with one or more extra fingers
- a common condition that often runs in families
- the extra fingers are usually small and abnormally developed
Polydactyly
- an inherited condition that leads to someone having very light skin, hair, and eyes
- it happens because they have less melanin than usual in their body
Albinism
