Mendelian Genetics Flashcards
What is common ancestry?
The concept that all living organisms share a common genetic heritage.
What do DNA and RNA carry?
Genetic information.
Who studied inheritance and created two laws applicable to genetics?
Gregor Mendel.
Why did Mendel choose pea plants for his experiments?
Many varieties, controlled mating, relatively short generation time.
What are the two distinct forms of traits tracked by Mendel?
Examples include color (purple or white) and seed shape (round or wrinkled).
What are true breeding plants?
Organisms that produce offspring of the same variety over many generations of self-pollination.
What does the P generation refer to?
The true-breeding parental generation.
What does the F1 generation represent?
The first filial hybrid offspring of the P generation.
What is a Punnett square?
A diagram used to predict the allele combinations of offspring from a known genetic cross.
In genetics, what do capital letters denote?
Dominant traits.
In genetics, what do lower case letters denote?
Recessive traits.
Define homozygous.
An organism that has a pair of identical alleles for a character.
What is the difference between homozygous dominant and homozygous recessive?
Homozygous dominant: AA; Homozygous recessive: aa.
Define heterozygous.
An organism that has two different alleles for a gene.
What is a genotype?
The genetic makeup (alleles) of an organism.
What is a phenotype?
An organism’s appearance, determined by the genotype.
What is a testcross used for?
To determine if a dominant trait is homozygous dominant or heterozygous.
What are the two fundamental principles of heredity discovered by Mendel?
The law of segregation and the law of independent assortment.
What happens when a purple and white true breeding pea plant are crossed?
Only purple F1 offspring are produced.
Did the white flower characteristic disappear in Mendel’s experiments?
No, it reappeared in the F2 generation.
What is the dominant trait in Mendel’s flower color experiments?
Purple flower color.
What was the observed phenotypic ratio in the F2 generation?
A 3:1 ratio.
What are alleles?
Alternative versions of genes that account for variations in inherited characteristics.
What does the law of segregation state?
The two alleles for the same trait separate during gamete formation.
What are somatic cells?
Diploid cells containing two copies of each chromosome.
What is a monohybrid cross?
A cross between two individuals that differ in one trait.
What is a dihybrid cross?
A cross between individuals that differ in two traits.
What is the law of independent assortment?
Genes for one trait are not inherited with genes for another trait.
What is the phenotypic ratio produced from a dihybrid cross?
A 9:3:3:1 ratio.
What is the multiplication rule in genetics?
The probability that two or more independent events will occur together in a specific combination.
What is the addition rule in genetics?
The probability that two or more mutually exclusive events will occur.
What are pedigrees?
Family trees that visually represent inheritance patterns of particular traits.
In reading pedigrees, what does a horizontal line represent?
A connection between parents.
In reading pedigrees, what does a vertical line represent?
A connection to children.
If a trait is dominant, what can be inferred about the parents?
At least one parent must have the trait.
True or False: Dominant traits can skip generations.
False.
What is the probability of having 3 girls in a row if the chance of having a girl is 1/2?
1/8.
What is the probability of the offspring being AaBbcc in the cross AABBCc x AaBbCc?
1/16.
