Inheritance Flashcards
What is Mendel’s First Law of Segregation?
The law states that during gamete formation, the two alleles for a trait segregate from each other.
What does Mendel’s Second Law of Independent Assortment state?
The law states that the alleles for different traits are distributed to gametes independently of one another.
In a monohybrid cross, how many traits are being studied?
One trait.
What is a Punnett square used for?
To predict the genotypic and phenotypic ratios of offspring from a genetic cross.
True or False: A dihybrid cross involves two traits.
True.
What is the phenotypic ratio typically expected from a monohybrid cross between two heterozygous individuals (Aa x Aa)?
3:1.
What is the genotypic ratio expected from a dihybrid cross (AaBb x AaBb)?
1:2:1:2:4:2:1:2:1.
Fill in the blank: In a Punnett square, the letters on the top represent the __________.
gametes of one parent.
What is the expected phenotypic ratio for a dihybrid cross of two heterozygous parents?
9:3:3:1.
What is a sex-linked trait?
A trait that is associated with a gene located on a sex chromosome.
True or False: Males are more likely to express sex-linked recessive traits than females.
True.
What does it mean for an allele to be dominant?
It means that the allele will express its trait even when only one copy is present.
In a monohybrid cross, what would the genotype of a homozygous recessive individual be represented as?
aa.
What is the purpose of using a test cross?
To determine the genotype of an individual exhibiting a dominant phenotype.
How many squares are in a standard Punnett square for a monohybrid cross?
Four squares.
If a trait is located on the X chromosome, what is it called?
X-linked.
What is the significance of the F1 generation in Mendelian genetics?
The F1 generation is the first filial generation resulting from a cross of the parental generation.
What does the term ‘homozygous’ mean?
An organism that has two identical alleles for a particular gene.
What does the term ‘heterozygous’ mean?
An organism that has two different alleles for a particular gene.
In a dihybrid cross, if one parent is homozygous dominant for both traits (AABB) and the other is homozygous recessive (aabb), what will be the genotype of the F1 generation?
All AaBb.
What is the expected phenotypic ratio from a cross between a homozygous dominant and a homozygous recessive individual?
All offspring will express the dominant phenotype.
Fill in the blank: The physical expression of a trait is called its __________.
phenotype.
What is the term for a cross involving two traits?
Dihybrid cross.
True or False: The allele for brown eyes (B) is dominant over the allele for blue eyes (b).
True.
