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ASU BIO 182 EXAM 2 AND PRACTICE EXAM
NEWEST 2024-2025 ACTUAL EXAM COMPLETE
160 QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A+
What are some disadvantages to linkage maps? - CORRECT
ANSWER-- Describes only relationship between genes
considered
- Ignores other genes
- Does not tell actual physical length of the chromosome
What are some deviations from Mendel's standard crosses? -
CORRECT ANSWER-- Gene interactions
- Incomplete dominance
- Pleiotropism
- Epistasis
- Heterosis
- Incomplete penetrance and expressivity
- Quantitative trait loci
- Epigenetics

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Incomplete dominance - CORRECT ANSWER-- Neither
completely dominates the other
- Is NOT blending inheritance
- Genes remain distinct units
- Results in a mixture
- F2 generations have homozygotes
Polygenic/
Quantitative/
Multifactoral inheritance - CORRECT ANSWER-Additive
effect of 2+ genes on a single character
Also, environment (e.g., nutrition) will affect height
Polygenic/Quantitative/Multifactoral Inheritance Example
Skin Color
AbBbCc x AaBbCc - CORRECT ANSWER-= aabbcc, Aabbcc,
AaBbCc, AABbCc, AABBCc, AABBCC
- Assume 3 genes
• Each parent is heterozygous
• A child could be light, dark—but most likely to be
intermediate

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Pleiotropic effects - CORRECT ANSWER-Single allele can
have multiple phenotypic effects
Pleiotropic Example
Allele for coloration pattern in Siamese cats - CORRECT
ANSWER-The same allele results in crossed eyes—both result
from the same protein
Epistasis - CORRECT ANSWER-Phenotypic expression of one
gene is influenced by another gene
Epistasis example:
Coat color in Labrador retrievers
- Allele B (black) dominant to b (brown)
- Allele E (pigment deposition) dominant
To e (no pigment deposition— yellow) - CORRECT ANSWERBlack - BBEE, BbEE, BBEe, BbEe
Brown - bbEE, bbEe
Yellow- BBee, Bbee, bbee

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Heterosis - CORRECT ANSWER-Cross between two different
true-breeding homozygotes can result in offspring with stronger,
larger phenotypes "Hybrid vigor"
Hybrid vigor - CORRECT ANSWER-Other word for heterosis
SNP - CORRECT ANSWER-Single Nucleotide Polymorphism
Environment x Genotype - CORRECT ANSWER-- Enviro can
affect phenotype
- Light, temp., nutrition, etc. can affect expression of the
genotype
Effects of genes and environment on phenotype: - CORRECT
ANSWER-Penetrance: Proportion of individuals in a population
with a certain genotype that show the phenotype, e.g.,
Huntington's
Expressivity: Degree to which genotype is expressed in an
individual
Penetrance - CORRECT ANSWER-Proportion of individuals in
a population with a certain genotype that show the phenotype,
e.g., Huntington's