Bio Unit 7 - Pedigrees & Punnett Squares
UPDATED ACTUAL Exam Questions and
CORRECT Answers
The form of a gene that is always expressed if present is the ______ form - CORRECT
ANSWER - dominant
Two heterozygous purple-flowering pea plants are crossed. If purple is dominant over white,
what are the expected phenotypic results? - CORRECT ANSWER - 75% purple, 25%
white
What law BEST explains why an organism with 'Tt' will show only the dominant phenotype? -
CORRECT ANSWER - law of DOMINANCE
If an organism inherits one dominant allele and one recessive allele for eye color, their genotype
would be: - CORRECT ANSWER - heterozygous
Two parents have the genotype Gg for a genetic disorder caused by a dominant allele. What is
the chance that any of their children will inherit the disorder? - CORRECT ANSWER -
25%
Which Mendelian law of inheritance states that organisms inherit two copies of each gene and
donate one copy to each of their offspring? - CORRECT ANSWER - Law of
SEGREGATION
In pigs, the allele for a wavy, rough coat (R) is dominant to the allele for a soft, fine coat (r). A
rough coat boar and a soft coat sow mate. They produce several litters, 50% are rough coat and
50% are smooth coat. What were the genotypes of the parents? - CORRECT ANSWER -
Rr x rr
, Imagine two heterozygous parents. Each has a dominant allele (B) for brown eyes and a
recessive allele (b) for blue eyes. What would the genotypic ratio of the offspring be? -
CORRECT ANSWER - 25% BB, 50% Bb, 25% bb
Identify the following genotypes as homo or heterogyzous: TT, Tt, tt - CORRECT
ANSWER - Homo, hetero, homo
If square is dominant to round, determine the phenotype for the following genotypes: SS, Ss, ss -
CORRECT ANSWER - Square, Square, Round
For an XX female to express a recessive sex-linked trait, she must have _________ - CORRECT
ANSWER - two recessive aleles
Human height occurs in a continuous range because it is affected by the interaction of several
genes, making it a(n) - CORRECT ANSWER - polygenic trait
Red hair and freckles are commonly inherited together. Which of following patterns of
inheritance explains this? - CORRECT ANSWER - Linked Genes
Which pair of genes in the diagram to the right would most likely be inherited together? -
CORRECT ANSWER -A& B
In a newly discovered species of flower, it was discovered that the color of the flower is
determined by two different genes. Which of the following inheritance patterns is this? -
CORRECT ANSWER - Polygenic Inheritance
Mutations can be caused by all of these except______? - CORRECT ANSWER - Global
warming
In order for a mutation to be passed on from parent to offspring, the mutation must occur in
______? - CORRECT ANSWER - gametes
UPDATED ACTUAL Exam Questions and
CORRECT Answers
The form of a gene that is always expressed if present is the ______ form - CORRECT
ANSWER - dominant
Two heterozygous purple-flowering pea plants are crossed. If purple is dominant over white,
what are the expected phenotypic results? - CORRECT ANSWER - 75% purple, 25%
white
What law BEST explains why an organism with 'Tt' will show only the dominant phenotype? -
CORRECT ANSWER - law of DOMINANCE
If an organism inherits one dominant allele and one recessive allele for eye color, their genotype
would be: - CORRECT ANSWER - heterozygous
Two parents have the genotype Gg for a genetic disorder caused by a dominant allele. What is
the chance that any of their children will inherit the disorder? - CORRECT ANSWER -
25%
Which Mendelian law of inheritance states that organisms inherit two copies of each gene and
donate one copy to each of their offspring? - CORRECT ANSWER - Law of
SEGREGATION
In pigs, the allele for a wavy, rough coat (R) is dominant to the allele for a soft, fine coat (r). A
rough coat boar and a soft coat sow mate. They produce several litters, 50% are rough coat and
50% are smooth coat. What were the genotypes of the parents? - CORRECT ANSWER -
Rr x rr
, Imagine two heterozygous parents. Each has a dominant allele (B) for brown eyes and a
recessive allele (b) for blue eyes. What would the genotypic ratio of the offspring be? -
CORRECT ANSWER - 25% BB, 50% Bb, 25% bb
Identify the following genotypes as homo or heterogyzous: TT, Tt, tt - CORRECT
ANSWER - Homo, hetero, homo
If square is dominant to round, determine the phenotype for the following genotypes: SS, Ss, ss -
CORRECT ANSWER - Square, Square, Round
For an XX female to express a recessive sex-linked trait, she must have _________ - CORRECT
ANSWER - two recessive aleles
Human height occurs in a continuous range because it is affected by the interaction of several
genes, making it a(n) - CORRECT ANSWER - polygenic trait
Red hair and freckles are commonly inherited together. Which of following patterns of
inheritance explains this? - CORRECT ANSWER - Linked Genes
Which pair of genes in the diagram to the right would most likely be inherited together? -
CORRECT ANSWER -A& B
In a newly discovered species of flower, it was discovered that the color of the flower is
determined by two different genes. Which of the following inheritance patterns is this? -
CORRECT ANSWER - Polygenic Inheritance
Mutations can be caused by all of these except______? - CORRECT ANSWER - Global
warming
In order for a mutation to be passed on from parent to offspring, the mutation must occur in
______? - CORRECT ANSWER - gametes
