Question 1

Which of the following is TRUE of blending inheritance?

Accepted Answer

A) Blending inheritance explains the disappearance of a trait several generations after it appeared. 
B) Blending inheritance leads to an increase in variation over time. 
C) Blending inheritance allows for rare variants of traits to increase in frequency. 
D) None of the answer options is correct. 
A) Blending inheritance explains the disappearance of a trait several generations after it appeared. 
B) Blending inheritance leads to an increase in variation over time. 
C) Blending inheritance allows for rare variants of traits to increase in frequency. 
D) None of the answer options is correct. D

Question 2

Genetic testing will:

Accepted Answer

A) identify every allele of every gene you carry. 
B) tell you whether or not you will contract breast cancer or Type II diabetes. 
C) identify some alleles of some of your genes. 
D) identify every risk factor you have for the most common types of cancer as well as for cardiovascular disease. 
E) None of the answer options is correct. 
A) identify every allele of every gene you carry. 
B) tell you whether or not you will contract breast cancer or Type II diabetes. 
C) identify some alleles of some of your genes. 
D) identify every risk factor you have for the most common types of cancer as well as for cardiovascular disease. 
E) None of the answer options is correct. C

Question 3

The term "dominant allele" is shorthand for an allele:

Accepted Answer

A) that always produces a functional product. 
B) that produces a functional product under certain conditions. 
C) whose presence results in a dominant trait. 
D) with epistasis that alters the expected F2 ratio of 9:3:3:1. 
A) that always produces a functional product. 
B) that produces a functional product under certain conditions. 
C) whose presence results in a dominant trait. 
D) with epistasis that alters the expected F2 ratio of 9:3:3:1. C

Question 4

A Punnett square can be used to interpret the results of a testcross.

Accepted Answer

A) True 
 B)False

Question 5

Why was the theory of blending inheritance eventually disproven?

Accepted Answer

A) Although the theory of blending inheritance accounted for a great deal of variation in a population, the theory of natural selection yielded explanations for every phenotype observed in a population. 
B) The theory of blending inheritance suggested that inheritance is a diversifying force, but it is actually a homogenizing force. 
C) It suggested that traits such as blue eyes were recessive, but such traits are in fact actually the result of rare dominant mutations arising in populations. 
D) It was based on the fact that the phenotypes of progeny of a given cross typically resemble either parentF1F1F1S1F1F1F10and never present "intermediate" phenotypes (i.e., such as grey fur). 
E) It was eventually disproven by demonstrating segregation of alleles for the inheritance of many traits in diverse types of organisms. 
A) Although the theory of blending inheritance accounted for a great deal of variation in a population, the theory of natural selection yielded explanations for every phenotype observed in a population. 
B) The theory of blending inheritance suggested that inheritance is a diversifying force, but it is actually a homogenizing force. 
C) It suggested that traits such as blue eyes were recessive, but such traits are in fact actually the result of rare dominant mutations arising in populations. 
D) It was based on the fact that the phenotypes of progeny of a given cross typically resemble either parentF1F1F1S1F1F1F10and never present "intermediate" phenotypes (i.e., such as grey fur). 
E) It was eventually disproven by demonstrating segregation of alleles for the inheritance of many traits in diverse types of organisms.

Question 6

Consider a gene with four alleles A1, A2, A3, and A4. If the cross A1A2 × A2A2 yields two offspring, what is the probability that they have the same genotype as each other?

Accepted Answer

A) 1/8 
B) 1/4 
C) 1/3 
D) 1/2 
E) 3/4 
A) 1/8 
B) 1/4 
C) 1/3 
D) 1/2 
E) 3/4

Question 7

You are given two true-breeding groups of gerbils. The gerbils in the first group have black coat color and curly tails; the gerbils in the second group have yellow coat color and straight tails. When you produce an F1 generation, you see only gerbils with black coat color and curly tails. When you produce an F2 generation, you see some gerbils with black coat color (75%) and some gerbils with yellow coat color (25%). You also see that some of the gerbils have straight tails (25%) and others (75%) have curly tails. If the single alleles responsible for coat color and tail appearance sort independently, how many of the black gerbils in this generation are expected to have straight tails?

Accepted Answer

A) 100% 
B) 75% 
C) 25% 
D) 0% 
A) 100% 
B) 75% 
C) 25% 
D) 0%

Question 8

Environmental factors are unlikely to affect variable expressivity in individuals.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following statements is TRUE regarding Charles Darwin?

Accepted Answer

A) Darwin subscribed to the idea of blending inheritance, which posed problems to certain aspects of his work. 
B) He believed that inheritance could be considered a homogenizing force. 
C) He established the theory of natural selection. 
D) He could not successfully synthesize the theory of blending inheritance with his theory of natural selection. 
E) All of these choices are correct. 
A) Darwin subscribed to the idea of blending inheritance, which posed problems to certain aspects of his work. 
B) He believed that inheritance could be considered a homogenizing force. 
C) He established the theory of natural selection. 
D) He could not successfully synthesize the theory of blending inheritance with his theory of natural selection. 
E) All of these choices are correct.

Question 10

You are examining a human pedigree for a trait. You notice that the trait appears in every generation; is equally likely to occur in males and females; and, when one parent is affected, about half of his or her offspring are affected. The trait is MOST likely:

Accepted Answer

A) dominant. 
B) recessive. 
C) epistatic. 
D) produced by multiple alleles. 
E) one that shows incomplete penetrance. 
A) dominant. 
B) recessive. 
C) epistatic. 
D) produced by multiple alleles. 
E) one that shows incomplete penetrance.

Question 11

In meiosis, allele separation at _____ is the chromosomal basis of segregation.

Accepted Answer

A) prophase 
B) metaphase 
C) anaphase 
D) telophase 
A) prophase 
B) metaphase 
C) anaphase 
D) telophase

Question 12

Mendel's principle of segregation corresponds to what part of meiosis?

Accepted Answer

A) condensation of chromosomes in prophase I 
B) alignment of homologs in metaphase I 
C) separation of homologs in anaphase I 
D) alignment of chromosomes in metaphase II 
E) separation of daughter chromatids in anaphase II 
A) condensation of chromosomes in prophase I 
B) alignment of homologs in metaphase I 
C) separation of homologs in anaphase I 
D) alignment of chromosomes in metaphase II 
E) separation of daughter chromatids in anaphase II

Question 13

When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were phenotypically:

Accepted Answer

A) yellow-seed plants. 
B) green-seed plants. 
C) a mixture of yellow and green seeds. 
D) made up of a combination of yellow and green alleles. 
A) yellow-seed plants. 
B) green-seed plants. 
C) a mixture of yellow and green seeds. 
D) made up of a combination of yellow and green alleles.

Question 14

According to the principle of segregation, a heterozygous plant with alleles Aa will produce:

Accepted Answer

A) gametes with only the A allele. 
B) gametes with only the a allele. 
C) gametes in the ratio of 1 A allele:1 a allele. 
D) gametes in the ratio of 3 A alleles:1 a allele. 
E) some gametes with the A allele and some with the a allele, but in no predictable ratio. 
A) gametes with only the A allele. 
B) gametes with only the a allele. 
C) gametes in the ratio of 1 A allele:1 a allele. 
D) gametes in the ratio of 3 A alleles:1 a allele. 
E) some gametes with the A allele and some with the a allele, but in no predictable ratio.

Question 15

Which of the following are benefits of genetic testing?

Accepted Answer

A) Newborns can be screened for treatable diseases. 
B) Individuals can find out whether or not they carry harmful recessive alleles. 
C) Adults can find out whether or not they have specific risk factors for some diseases. 
D) Physicians can use the results of genetic testing to engineer drugs specific for an individual's genotype. 
E) None of the answer options is correct. 
A) Newborns can be screened for treatable diseases. 
B) Individuals can find out whether or not they carry harmful recessive alleles. 
C) Adults can find out whether or not they have specific risk factors for some diseases. 
D) Physicians can use the results of genetic testing to engineer drugs specific for an individual's genotype. 
E) None of the answer options is correct.

Question 16

When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were genotypically:

Accepted Answer

A) yellow seed. 
B) green seed. 
C) a mixture of yellow and green seed. 
D) made up of a combination of yellow and green alleles. 
A) yellow seed. 
B) green seed. 
C) a mixture of yellow and green seed. 
D) made up of a combination of yellow and green alleles.

Question 17

A trait with incomplete penetrance is one that:

Accepted Answer

A) is only expressed in homozygous recessive individuals. 
B) is only expressed in homozygous dominant individuals. 
C) is only expressed in some of the individuals that have the genotype for that trait. 
D) is expressed in only some offspring of affected individuals. 
E) can be expressed differently in different individuals that have the genotype for that trait. 
A) is only expressed in homozygous recessive individuals. 
B) is only expressed in homozygous dominant individuals. 
C) is only expressed in some of the individuals that have the genotype for that trait. 
D) is expressed in only some offspring of affected individuals. 
E) can be expressed differently in different individuals that have the genotype for that trait.

Question 18

Consider a gene with four alleles A1, A2, A3, and A4. How many distinct genotypes are possible, taking into account both homozygous and heterozygous genotypes?

Accepted Answer

A) 6 
B) 7 
C) 8 
D) 9 
E) 10 
A) 6 
B) 7 
C) 8 
D) 9 
E) 10

Question 19

While doing a pedigree analysis of a European royal family, you notice a disease in a female child of two healthy parents. There are also some cousins with the same genetic disease. If this disease is controlled by a single gene, then the MOST likely explanation for these observations is that the disease is:

Accepted Answer

A) a spontaneous mutation. 
B) recessive and only seen in homozygous recessive individuals such as the daughter. 
C) dominant and only seen in homozygous dominant individuals such as the daughter. 
D) only seen in heterozygous individuals such as the daughter. 
E) dominant and is seen in homozygous dominant or heterozygous individuals. 
A) a spontaneous mutation. 
B) recessive and only seen in homozygous recessive individuals such as the daughter. 
C) dominant and only seen in homozygous dominant individuals such as the daughter. 
D) only seen in heterozygous individuals such as the daughter. 
E) dominant and is seen in homozygous dominant or heterozygous individuals.

Question 20

In the F2 generation of Mendel's monohybrid crosses, the 1:2:1 ratio refers to:

Accepted Answer

A) single-nucleotide polymorphisms (SNPs). 
B) copy-number variations (CNVs). 
C) variable number of tandem repeats (VNTRs). 
D) genotypes. 
E) phenotypes. 
A) single-nucleotide polymorphisms (SNPs). 
B) copy-number variations (CNVs). 
C) variable number of tandem repeats (VNTRs). 
D) genotypes. 
E) phenotypes.

Exam 16: Mendelian Inheritance

Which of the following is TRUE of blending inheritance?

Genetic testing will:

The term "dominant allele" is shorthand for an allele:

A Punnett square can be used to interpret the results of a testcross.

Why was the theory of blending inheritance eventually disproven?

Consider a gene with four alleles A1, A2, A3, and A4. If the cross A1A2 × A2A2 yields two offspring, what is the probability that they have the same genotype as each other?

Environmental factors are unlikely to affect variable expressivity in individuals.

Which of the following statements is TRUE regarding Charles Darwin?

You are examining a human pedigree for a trait. You notice that the trait appears in every generation; is equally likely to occur in males and females; and, when one parent is affected, about half of his or her offspring are affected. The trait is MOST likely:

In meiosis, allele separation at _____ is the chromosomal basis of segregation.

Mendel's principle of segregation corresponds to what part of meiosis?

When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were phenotypically:

According to the principle of segregation, a heterozygous plant with alleles Aa will produce:

Which of the following are benefits of genetic testing?

When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were genotypically:

A trait with incomplete penetrance is one that:

Consider a gene with four alleles A1, A2, A3, and A4. How many distinct genotypes are possible, taking into account both homozygous and heterozygous genotypes?

In the F2 generation of Mendel's monohybrid crosses, the 1:2:1 ratio refers to:

Life: Chemical, Cellular, and Evolutionary Foundations

The Molecules of Life

Nucleic Acids and Transcription

Translation and Protein Structure

Organizing Principles: Lipids, Membranes, and Cell Compartments

Making Life Work: Capturing and Using Energy

Cellular Respiration: Harvesting Energy From Carbohydrates and Other Fuel Molecules

Photosynthesis: Using Sunlight to Build Carbohydrates

Cell Signaling

Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Cell Division: Variations, Regulation, and Cancer

Dna Replication and Manipulation

Genomes

Mutation and Dna Repair

Genetic Variation

Inheritance of Sex Chromosomes, Linked Genes, and Organelles

The Genetic and Environmental Basis of Complex Traits

Genetic and Epigenetic Regulation

Genes and Development

Evolution: How Genotypes and Phenotypes Change Over Time

Species and Speciation

Evolutionary Patterns: Phylogeny and Fossils

Human Origins and Evolution

Cycling Carbon

Bacteria and Archaea

Eukaryotic Cells: Origins and Diversity

Being Multicellular

Plant Structure and Function: Moving Photosynthesis Onto Land

Plant Reproduction: Finding Mates and Dispersing Young

Plant Growth and Development

Plant Defense: Keeping the World Green

Plant Diversity

Fungi: Structure, Function, and Diversity

Animal Nervous Systems

Animal Sensory Systems and Brain Function

Animal Movement: Muscles and Skeletons

Animal Endocrine Systems

Animal Cardiovascular and Respiratory Systems

Animal Metabolism, Nutrition, and Digestion

Animal Renal Systems: Water and Waste

Animal Reproduction and Development

Animal Immune Systems

Animal Diversity

Animal Behavior

Population Ecology

Species Interactions, Communities, and Ecosystems

Biomes and Global Ecology

The Anthropocene: Humans As a Planetary Force

Filters

Consider a gene with four alleles A₁, A₂, A₃, and A₄. If the cross A₁A₂ × A₂A₂ yields two offspring, what is the probability that they have the same genotype as each other?

Consider a gene with four alleles A₁, A₂, A₃, and A₄. How many distinct genotypes are possible, taking into account both homozygous and heterozygous genotypes?

In the F₂ generation of Mendel's monohybrid crosses, the 1:2:1 ratio refers to: