Bio 123 Chapter 9
Gregor Mendel solved the puzzle of heredity when?
1865
What is a Dihybrid cross?
A cross between individuals that have different alleles for the same gene
What is a Monohybrid cross?
A cross between individuals that involves one pair of contrasting traits
What is a punnet square?
A diagram that predicts the outcome of a genetic cross by considering all possible combinations of gametes in the cross.
What is the law of segregation?
Allele pairs separate from each other during the production of gametes so that a sperm or egg carries only one allele for each gene
What is an alternative version of genes?
Alleles
What is the Pleiotropic effect?
An allele that has more than one effect on the phenotype
Polygenic is what?
Continuous variation characters can show a range of small differences when multiple genes act jointly to influence a character
What were the four advantages of using pea plants?
Controlled matting, Self-fertilization or Cross-fertilization, Observable characteristic with two distinct forms, and True-breeding strains
Hetrozygous have ______ allele on each homologue
Different
What is the law of independent assortment?
Each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random
Mendel discovered the principle of genetics in experiments with what?
Garden Peas
Why does one trait seem to disappear in the F1 generation?
It disappears because one trait is recessive and the other is dominant
What is a Homozygous genotype?
It has identical alleles
What is a Hetrozygous genotype?
It has two different alleles
What are Environmental effects?
It is the degree to which many alleles are expressed depends on their environment
What is a genotype?
It is the listing of alleles an individual carries for a specific gene
What is the F1 generation?
It is the offspring of the P generation
What is the P generation?(may need more detail)
It is the parental generation
What is a Test cross?
It is way to determine the genotype of unknown individuals in the F2 generation
What is the F2 generation?(may need more detail)
It is when F1 self-fertilizes produce two different traits
Why does the recessive trait reappear in one quarter of the F2 offspring?(may need more detail)
It reappears because the offspring will have two non dominant genes
Pleiotropic is defined as?
One gene that affects many characters
Homozygous individuals have the ____ allele on both homologues
Same
What allele determines an organism's appearance?
The Dominant
What allele has no noticeable effect?
The Recessive
A pedigree shows what?
The inheritance of a trait in a family through multiple generations(demonstrating dominant or recessive inheritance)
What is co-dominance?
There is no dominant allele, but both alleles are expressed
Mendel and T.A Knights experiments established what?
True-breeding varieties by allowing plants to self-fertilize for several generations, to contain specific traits
What is incomplete dominance?
not all alternative alleles are either fully dominant or fully recessive in heterozygoes
