Chapter 14 - Mendelian Genetics Flashcards
Who is Gregor Mendel?
Gregor Mendel discovered heredity in garden peas. He entered into a monastery and started breeding garden peas to study inheritance.
What did Gregor Mendel do?
He bred garden peas and found different inherited traits in the offspring of the plants.
What is true breeding?
True breeding are generations of plants that are self pollinated and have the same traits (parent plants)
What is hybridization?
The crossing of two true-breeding (parent) varieties.
What is the P Generation?
Parental generation
What is the F1 generation?
1st filial generation (filial comes from the latin word for son)
What is the F2 generation?
2nd filial generation (filial comes from the latin word for son)
what is a phenotype?
the observable traits, What you can see on the appearance
What is a genotype?
the genetic make up
What is the 1st part of the Mendel’s Model?
Alternate versions of genes account for variations in inherited characters. These alternate versions are called alleles.
What is the 2nd part of Mendel’s Model?
For each character, an organism inherits two copies of a gene, one from each parent
What is the 3rd part of Mendel’s Model?
If the two alleles at a locus differ, then one, the dominant allele, will determime the organism’s appearance; the other, the recessive allele, has no noticeable effect on the organism’s appearance.
What is the 4th part of Mendel’s Model?
Is The law of segregation which states two alleles for a heritable character segregate during gamete formation and end up in different gametes.
What is Mendel’s Model?
It is a model that Mendel developed to explain the 3:1 inheritance pattern that he consistently observed among the F2 offspring in his pea experiments.
What is a Homozygous gene?
A pair of identical alleles for a gene (PP, pp, etc.)
What is a heterozygous gene?
A pair of two different alleles for a gene (Pp, etc.)
What is an allele?
alternative versions of a gene; ex. Pp a Capital P and a lower case p are two different alleles.
What does testcross mean?
It is the breeding of an organism of unknown genotype with a recessive homozygote to figure out the unknown genotype.
What is a monohybrid?
They are heterozygous for one characteristic being followed through the cross
What is a dihybrid?
Heterozygous for two characteristics being followed through the cross.
What is the Law of Independent Assortment?
- Each pair of alleles segregate independently of each other pair of alleles during gamete formation.
- The law only applies to genes (allele pairs) located on different chromosomes
- Mendel test using Dihybrid crosses
Laws of probability is…?
You have a 50% chance of getting one of the alleles from one of the gametes. Its like flipping a coin.
What is the multiplication rule?
Ex. When you try to determine the probability that two or more independent events will occur together in some specific combination, you will multiply the probability of one event happening by the probability of the other event. Then you can find the probability of events happening at the same time.
When do you use the addition rule?
If you are looking for the probability of more than one outcome.
What is Incomplete dominance?
Neither allele is completely dominant heterozygous offspring will be somewhere in between the parent alleles. (A mixture of colors: Red and white flowers breed and make pink offspring)
What is Codominance?
Two alleles each will affect the phenotype in separate, distinguishable ways.. (They both show up)
What is Multiple Alleles?
Even though pea plants have two alleles, most genes have more than two alleles. (Ex. Blood types: I^A, I^B, i; A, AB, B or O)
What is Pleiotropy?
A gene affects more than one trait.
What is Epistasis?
The phenotypic expression of a gene at one locus alters that of a gene at a second locus. (Ex. Labrador retrievers; Black Labs will breed and will create offspring with brown, black and golden fur.)
What is Polygenic Inheritance?
Its the additive effect of two or more genes on a single phenotypic character. Like shades of skin color.
What is Quantitative Characters?
Characteristics that vary in a population in gradations along a continuum
- Usually due to genetic input from two or more genes
- Examples - skin color, height, eye color
Can Nature effect phenotypes?
Hydrangea flowers range in color due to acidity and aluminum content of the soil.
What is a Pedigree?
A pedigree analysis can trace where certain traits come from
- diseases can be traced back through a family.
