USI Bio 141 Exam 3 2026 Questions and
Answers
Mendel developed a hypothesis to explain the ______ inheritance pattern he
observed in ____ offspring - Correct answer-3:1, F2
Alternative versions of genes account for..... - Correct answer-Variations in
inherited genes
Alternative versions of a gene are called ________ - Correct answer-Alleles
Each gene resides at a specific _______ on a specific chromosome - Correct
answer-Locus
An organism inherits ____ alleles, _____ from each parent - Correct answer-2, 1
T or F: the two alleles at a particular locus may be identical. - Correct answer-True,
an example is in the true breeding plants of Mendel's P generation
T or F: In the F1 hybrids, the locus may differ - Correct answer-True
The __________ determines the organisms appearance - Correct answer-Dominant
allele
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,When referring to alleles, the __________ has no noticeable affect on appearance.
- Correct answer-Recessive allele
two alleles for a heritable character separating during gamete formation and ending
up in different gametes is known as ______ - Correct answer-The Law of
Segregation
Because of the Law of Segregation, an egg or sperm gets ________ - Correct
answer-one of the two alleles that are present in the organism.
The segregation of alleles corresponds to the distribution of..... - Correct answer-
homologous chromosomes to different gametes in meiosis
In the P Generation, for purple flowers to white flowers, what is the cross? -
Correct answer-PPxpp
An organism with two identical alleles for a character is ______ for the gene
controlling the character - Correct answer-homozygous
An organism that has two different alleles for a gene is ________ for the gene
controlling that character - Correct answer-heterozygous
Unlike homozygotes, heterozygotes are not _________ - Correct answer-True
Breeding
Phenotype = - Correct answer-Physical appearance
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, Genotype = - Correct answer-Genetic Makeup
a testcross determines: - Correct answer-if an individual is Homozygous dominant,
or Heterozygous
A testcross works by: - Correct answer-Breeding the individual with a homozygous
recessive individual. If any offspring show a recessive phenotype, the parent must
be heterozygous.
Probability of AABB on a dihybrid cross of AaBb x AaBb - Correct answer-1/16
Probability of AaBB on a dihybrid cross of AaBb x AaBb - Correct answer-
(1/2)(1/4)= 1/8
Probability of AaBb on a dihybrid cross of AaBb x AaBb - Correct answer-
(1/2)(1/2)= 1/4
_________ occurs when phenotypes of the heterozygote and dominant
homozygote are identical - Correct answer-Complete Dominance
________ is when the phenotype of F1 hybrids is somewhere between the
phenotypes of the two parental varieties - Correct answer-Incomplete Dominance
________ is when two dominant alleles affect the phenotype in separate,
distinguishable ways - Correct answer-Codominance
Genotypes for a type A Blood group - Correct answer-I^AI^A or I^Ai
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
Answers
Mendel developed a hypothesis to explain the ______ inheritance pattern he
observed in ____ offspring - Correct answer-3:1, F2
Alternative versions of genes account for..... - Correct answer-Variations in
inherited genes
Alternative versions of a gene are called ________ - Correct answer-Alleles
Each gene resides at a specific _______ on a specific chromosome - Correct
answer-Locus
An organism inherits ____ alleles, _____ from each parent - Correct answer-2, 1
T or F: the two alleles at a particular locus may be identical. - Correct answer-True,
an example is in the true breeding plants of Mendel's P generation
T or F: In the F1 hybrids, the locus may differ - Correct answer-True
The __________ determines the organisms appearance - Correct answer-Dominant
allele
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,When referring to alleles, the __________ has no noticeable affect on appearance.
- Correct answer-Recessive allele
two alleles for a heritable character separating during gamete formation and ending
up in different gametes is known as ______ - Correct answer-The Law of
Segregation
Because of the Law of Segregation, an egg or sperm gets ________ - Correct
answer-one of the two alleles that are present in the organism.
The segregation of alleles corresponds to the distribution of..... - Correct answer-
homologous chromosomes to different gametes in meiosis
In the P Generation, for purple flowers to white flowers, what is the cross? -
Correct answer-PPxpp
An organism with two identical alleles for a character is ______ for the gene
controlling the character - Correct answer-homozygous
An organism that has two different alleles for a gene is ________ for the gene
controlling that character - Correct answer-heterozygous
Unlike homozygotes, heterozygotes are not _________ - Correct answer-True
Breeding
Phenotype = - Correct answer-Physical appearance
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, Genotype = - Correct answer-Genetic Makeup
a testcross determines: - Correct answer-if an individual is Homozygous dominant,
or Heterozygous
A testcross works by: - Correct answer-Breeding the individual with a homozygous
recessive individual. If any offspring show a recessive phenotype, the parent must
be heterozygous.
Probability of AABB on a dihybrid cross of AaBb x AaBb - Correct answer-1/16
Probability of AaBB on a dihybrid cross of AaBb x AaBb - Correct answer-
(1/2)(1/4)= 1/8
Probability of AaBb on a dihybrid cross of AaBb x AaBb - Correct answer-
(1/2)(1/2)= 1/4
_________ occurs when phenotypes of the heterozygote and dominant
homozygote are identical - Correct answer-Complete Dominance
________ is when the phenotype of F1 hybrids is somewhere between the
phenotypes of the two parental varieties - Correct answer-Incomplete Dominance
________ is when two dominant alleles affect the phenotype in separate,
distinguishable ways - Correct answer-Codominance
Genotypes for a type A Blood group - Correct answer-I^AI^A or I^Ai
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
