ASU BIO 182 EXAM 2 AND PRACTICE EXAM

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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 2 / 4

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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 ANSWER - Black - 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

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