Alleles And Inheritance Flashcards
What did the experiments on pea plants determine about traits?
Traits are determined by alleles for any given characteristic.
What does the combination of alleles in an organism represent?
Genotype.
What is the expressed trait of an organism called?
Phenotype.
What is the genotype of a yellow hybrid in pea plants?
Heterozygous (Yy).
Fill in the blank: The parental generation in genetics is referred to as the _______.
P generation.
What does homozygous mean?
Having two identical alleles for a given trait.
What is the significance of the genotype in determining phenotype?
The genotype determines the expressed trait (phenotype).
What does the Law of Segregation state?
During meiosis, the alleles of a gene separate randomly into individual gametes.
What is the definition of genotype?
The genetic constitution of an organism, represented by alleles.
What is the definition of phenotype?
The observable characteristics or traits of an organism.
What is a Punnett Square?
A grid used to show the probability of offspring’s genotype and phenotype.
What is the gamete genotype for a dominant yellow allele in pea plants?
Y
What is the gamete genotype for a recessive green allele in pea plants?
y
What is the phenotype ratio when two heterozygous pea plants are crossed?
75% yellow : 25% green (3:1)
What is the genotype ratio for offspring from a cross of two heterozygous pea plants?
1 YY : 2 Yy : 1 yy (1:2:1)
Fill in the blank: The dominant allele for color in pea plants is represented by _______.
Y
Fill in the blank: The recessive allele for color in pea plants is represented by _______.
y
What percentage of offspring will be homozygous dominant when crossing two heterozygous pea plants?
25%
What percentage of offspring will be homozygous recessive when crossing two heterozygous pea plants?
25%
What is a test cross?
To determine the presence of a recessive allele within an individual with dominant phenotype, by crossing them with a homozygous recessive individual
This helps identify if the dominant phenotype individual is homozygous or heterozygous.
What are the genotypes and phenotypes of the offspring from a cross between BB and bb?
Genotype: 100% Bb, Phenotype: 100% brown
This scenario demonstrates a cross between homozygous dominant and homozygous recessive.
What are the genotypes and phenotypes of the offspring from a cross between Bb and bb?
Genotype: 50% Bb, 50% bb; Phenotype: 50% brown, 50% blue
This scenario illustrates a cross between a heterozygous and a homozygous recessive individual.
If an individual produces only offspring with a dominant phenotype, what can be concluded about that individual’s genotype?
The individual is homozygous dominant
This means they carry two dominant alleles.
If an individual with a dominant trait produces even one offspring with a recessive phenotype, what can be concluded about that individual’s genotype?
The individual is heterozygous dominant
This means they carry one dominant allele and one recessive allele.