simple genetics
what is Mendelian genetics also known as?
Gregor Mendel
-austrian monk -father of genetics
Characteristic or Trait
the physical features that are inherited. They can occur in different versions.
characteristic, trait, version, trait
Face color is _________ or _____. White or not white is the _______ of the ____.
hybrid
offspring from a cross of parents with different or contrasting traits
Generation
a group of offspring from a given group of parents
Genetics
the study of heredity
Genetic cross
mating or breeding of two individual organisms
Self pollinate
fertilize itself
Cross pollinate
pollen of one plant is carried to the flower of another plant
monohybrid cross
a cross studying one pair of contrasting forms of a trait
True-breeding
plants or organisms that always produce the same type of offspring. Also called Pure bred.
Mendel’s explanations for the patterns of heredity in garden pea plants.
Modern genetics is based on
People thought that traits were blends from parents.
Before Mendel what did people believe about how we inherited traits?
-They have seven traits with two contrasting forms for each trait -They usually self pollinate -Grow easily
Why did Mendel choose pea plants to study?
Mendel allowed true-breeding plants for each trait to self fertilize and called these true or pure bred plants the parental or P generation.
Mendel’s First Experiments step 1:
parental or p generation
the first set of parents crossed
He then crossed two true breeding plants of the same character but with different forms of the trait.
Mendel’s First Experiments step 2:
first filial or F1 generation
the generation of hybrids produced from a cross between the genetically different individuals called parents
He then allowed the F1 generation to self fertilize and produce new plants. He called the offspring from this cross the second filial or F2 generation.
Mendel’s First Experiments step 3:
alleles
different versions of genes
dominant
the expressed allele( what showed up in the F1
recessive
the hidden allele(didn’t show up in the F1)
genotype
a specific combination of alleles in an individual.(the actual genetic makeup)
phenotype
the detectable trait or traits that result from the genotype of an individual(the observable form of the trait
The simple pattern of inheritance. In these patterns, two of several versions of a gene combine and result in one of several possible traits.
what does Mendelian theory explain
Mendel called the version that showed up the ________ trait and the one that was hidden the _________ trait
Law of dominance
that the dominant allele is the one that showed up in the F1 generation
Law of independent assortment
during gamete formation the alleles of each gene segregate independently.
phenotype
The physical trait or the observable form of the trait
genotypes
are the genes that code for these traits
capital, lower case
We use a ______ letter to represent the dominant gene and a ________ letter to represent the recessive gene
pure bred
said to be Homozygous for the trait.
hybrid
said to be Heterozygous for the trait.
homozygous
an individual that carries two identical alleles of a gene
heterozygous
individual that carries two different alleles of a gene
gene
unit of heredity; part of the DNA that codes for a particular protein
Dihybrid crosses
When you cross two traits at a time
Incomplete Dominance
The heterozygote shows an inbetween or blend of the two homozygous phenotypes Red x white = pink Black x white= gray Long x short =medium
Co dominance
the heterozygote shows both homozygous phenotypes. Red x white= red/white
Phenotypes: Genotypes: Type A IA IA or IA iType B IB IB or IB i Type O ii Type AB IA IB
human blood type
type AB
blood is an example of codominance
multiple alleles
Human blood type shows
mutiple alleles
More than the normal two alleles for a trait
2
Each organism can only have _____ of the alleles for that trait to be expressed
polygenic traits
Traits that have more than one pair of genes involved in their expression -hair color -eye color -skin color
Studied by 59 People