Genetics and Dihybrid Flashcards
(15 cards)
What does it mean when a trait follows Mendelian genetics?
The trait is controlled by two alleles where one is dominant and the other is recessive
Mendelian genetics refers to the inheritance patterns established by Gregor Mendel, which involve dominant and recessive alleles.
Define Genes
A segment of DNA on a chromosome that codes for specific proteins and traits
Define Alleles
Different versions of a gene (A or a)
Alleles can be dominant or recessive, influencing the phenotype of an organism.
Define Homozygous
Two of the same alleles (AA or aa)
Homozygous individuals have identical alleles for a trait.
Define Heterozygous
Two different alleles (Aa)
Heterozygous individuals have one dominant and one recessive allele for a trait.
Define Dominant
The allele that shows up when 2 different or 2 dominant alleles are present
Dominant alleles mask the expression of recessive alleles in a heterozygous genotype.
Define Recessive
The allele that is only expressed if 2 copies are present
Recessive traits may not be visible in heterozygous individuals.
Define Genotype
The genetic makeup of a specific set of genes — combination of alleles
Genotype determines the potential traits an organism can express.
Define Phenotype
The physical trait that shows up from a genotype
Phenotype is influenced by both genotype and environmental factors.
What does the Punnett square represent?
Shows the possible genetic combinations of an offspring using the male and female gamete possibilities made during meiosis
It provides the probability of each genotype and phenotype in the offspring.
What is Mendel’s Law of Segregation?
When producing gametes, the two alleles for each trait separate during meiosis
This law explains how alleles are distributed to gametes, ensuring genetic diversity.
What is a dihybrid cross?
Shows the results of crossing two individuals with two traits
Dihybrid crosses examine the inheritance patterns of two different traits simultaneously.
What is Mendel’s Law of Independent Assortment?
Genes on separate chromosomes sort independently during meiosis
This law explains how different traits are inherited independently of each other.
How many letters should be in a complete parent genotype for a dihybrid cross?
4
Each parent contributes two alleles for each of the two traits being analyzed.
How do you complete the possible gamete combinations for AaBb?
AB, Ab, aB, ab
These combinations represent all possible gametes produced by the heterozygous parents.
