Inheritance and Punnett Squares Flashcards
What is the basic unit of heredity?
Gene
True or False: Alleles are different forms of a gene.
True
What does the term ‘homozygous’ mean?
Having two identical alleles for a particular gene.
What does the term ‘heterozygous’ mean?
Having two different alleles for a particular gene.
Fill in the blank: The physical expression of a trait is known as its _____.
Phenotype
What is the genetic makeup of an organism referred to as?
Genotype
In a Punnett square, what does each box represent?
A possible genotype of the offspring.
If a plant has a genotype of Aa, what are the possible gametes it can produce?
A and a
What is the ratio of offspring phenotypes in a monohybrid cross of two heterozygous parents (Aa x Aa)?
3:1
True or False: The dominant allele is always expressed in the phenotype.
True
What does a Punnett square illustrate?
The possible genetic combinations from a cross.
If a homozygous dominant plant (AA) is crossed with a homozygous recessive plant (aa), what will the genotype of the offspring be?
All Aa
What is the expected phenotypic ratio of a dihybrid cross (AaBb x AaBb)?
9:3:3:1
Fill in the blank: A trait that is expressed only when two recessive alleles are present is called a _____ trait.
Recessive
What does the term ‘test cross’ refer to?
Crossing an unknown genotype with a homozygous recessive.
What is the purpose of using a Punnett square?
To predict the probability of genotypes and phenotypes in offspring.
In a cross between two pea plants (one yellow pod, one green pod), if yellow is dominant, what symbol can represent the yellow allele?
Y
True or False: Incomplete dominance results in a blend of traits in the offspring.
True
What type of inheritance pattern involves multiple genes affecting a trait?
Polygenic inheritance
What is the expected genotype ratio from a monohybrid cross of Aa x Aa?
1 AA : 2 Aa : 1 aa
Fill in the blank: The observable characteristics of an organism are referred to as its _____.
Phenotype
When two traits are examined at once, what type of Punnett square is used?
Dihybrid Punnett square
What does the term ‘carrier’ refer to in genetics?
An individual who has one copy of a recessive allele but does not express the trait.
If a red flower (RR) is crossed with a white flower (rr) and the offspring are all pink (Rr), what type of inheritance is this?
Codominance
What is the purpose of a pedigree chart?
To track inheritance patterns of traits across generations.
True or False: Sex-linked traits are only found on the X chromosome.
False
