R Flashcards
What is a recessive allele?
An allele that only expresses its trait when two copies are present.
True or False: A recessive trait can be expressed in an individual with one dominant allele.
False
Fill in the blank: An individual with two recessive alleles for a trait is said to be _____ for that trait.
homozygous
What is the genotype of an individual who is heterozygous for a recessive trait?
One dominant allele and one recessive allele.
Multiple choice: Which of the following is an example of a recessive genetic disorder?
Cystic fibrosis
Define ‘carriers’ in the context of recessive traits.
Individuals who have one recessive allele and one dominant allele but do not express the recessive trait.
True or False: Recessive traits can skip generations.
True
What is the phenotypic ratio expected in a monohybrid cross involving one recessive trait?
3:1
Fill in the blank: In a pedigree chart, recessive traits are often represented by _____ symbols.
colored
What is the likelihood of two heterozygous parents producing an offspring with a recessive trait?
25%
Multiple choice: Which of the following genotypes represents a recessive phenotype?
aa
What term describes the observable characteristics of an organism?
Phenotype
True or False: A recessive trait will always appear in every generation.
False
What is the relationship between dominant and recessive alleles?
Dominant alleles mask the expression of recessive alleles.
Fill in the blank: If a trait is recessive, it will only show in the phenotype if the genotype is _____ or _____ for that trait.
homozygous recessive
Multiple choice: Which of the following is NOT a characteristic of recessive traits?
They are always expressed in the phenotype.
What does it mean if an individual is homozygous recessive for a trait?
They have two identical recessive alleles.
True or False: In a genetic cross, a recessive trait can be expressed if it is paired with another recessive allele.
True
What is the expected phenotypic ratio of a dihybrid cross involving two recessive traits?
9:3:3:1
Fill in the blank: The location of a gene on a chromosome is called its _____ .
locus
Define ‘homozygous dominant’ in relation to recessive traits.
An individual with two dominant alleles for a trait.
Multiple choice: Which of the following genetic crosses would most likely result in recessive offspring?
Crossing two homozygous recessive parents.
What happens when a recessive allele is paired with a dominant allele?
The dominant allele’s trait is expressed.
True or False: Recessive traits are always less common in a population compared to dominant traits.
False
