Questions and Answers
What does the term 'true breeding' mean?
Why was Mendel successful at tracking patterns of inheritance whereas other scientists were not?
A recessive trait is one that is:
A dominant trait is one that:
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A monohybrid cross is one in which:
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A heritable factor that exists in two forms is also known as a(n):
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An organism that inherits two different alleles for a single trait, one from its mother and one from its father is known as a(n):
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An organism that inherits two identical alleles, one from its mother and one from its father is known as a(n):
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An organism's allelic constitution is also known as its:
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The physical appearance of an organism is known as its:
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In a monohybrid cross, if the P generation consists of plants that are true breeding (one is homozygous dominant, the other homozygous recessive) then the F2 generation will consist of organisms that exhibit what ratio of dominant phenotypes to recessive phenotypes?
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In a monohybrid cross, if the P generation consists of plants that are true breeding (one is homozygous dominant, the other homozygous recessive) then the F2 generation will consist of organisms that exhibit what ratio of homozygous dominant individuals to heterozygous individuals to homozygous recessive individuals?
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Which of the following is a principle that Mendel discovered using monohybrid crosses?
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The principle of dominance states that:
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The principle of segregation states that:
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A dihybrid cross is one in which:
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In a dihybrid cross, if the P generation consists of plants that are true breeding (one is homozygous dominant, the other homozygous recessive) then the F2 generation will consist of organisms that exhibit what phenotypic ratio?
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The principle of independent assortment states that:
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Which of the following is a principle that Mendel discovered using dihybrid crosses?
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In tigers, a recessive allele causes a white tiger. If two phenotypically normal tigers are mated and produce a white offspring, what percentage of their remaining offspring is expected to be white?
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A man was born with six fingers on each hand and six toes on each foot. His wife and their son have a normal number of digits. Having extra digits is a dominant trait. The couple's second child has extra digits. What is the probability that their next child will have extra digits, assuming that the trait exhibits complete penetrance?
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What is a genetic cross between one homozygous recessive individual and one of unknown genotype?
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Black fur in mice is dominant to brown fur. Short tails are dominant to long tails. What proportion of the offspring from a cross between an individual with the genotype BbTt and BBtt will have black fur and long tails?
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In a trihybrid cross, the expected proportion of offspring showing all three recessive traits is:
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In a cross AABBCC and aabbcc (P generation), what would be the phenotypic frequency of A_bbC_ in the F2 (produced by an F1 self cross), where ___= dominant or recessive allele?
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Which of the following is a method for analyzing a cross involving 2 genes?
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In the Chi-Square test a critical value is:
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The chi-square statistic is calculated as:
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The degrees of freedom associated with a Chi-Square test is equal to:
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You perform a dihybrid cross between two plants that have traits expressing a simple dominance relationship. Then, you self the F1 generation and analyze the progeny. How many degrees of freedom do you have for your chi-square test?
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Biologists tend to reject the conclusion that the deviation is due to chance if the probability is less than:
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Why has progress studying the genetic traits of human beings been slow?
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A diagram that is used to show the relationships between family members and is used to track genetic traits is known as a(n):
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In a pedigree analysis, which of the following would represent an affected male?
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If there are only two possible phenotypic classes, the probabilities associated with the various outcomes is referred to as:
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Study Notes
Genetics Key Concepts
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True Breeding: Organisms that exhibit little genetic variation across generations, ensuring consistency in obtained traits.
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Mendel's Success: Utilized the garden pea as a model organism, tracked one contrasting phenotypic characteristic at a time, and employed true breeding methods, leading to significant discoveries.
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Recessive Traits: Traits that are masked by dominant traits in the presence of both in the genotype.
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Dominant Traits: Traits that will always be expressed if present in the genotype, overshadowing recessive traits.
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Monohybrid Cross: Focuses on one trait at a time, allowing for the analysis of inheritance patterns.
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Alleles: Different forms of a gene; two alleles for a trait contribute to genetic diversity.
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Heterozygote vs. Homozygote: A heterozygote has two different alleles for a trait, while a homozygote has identical alleles.
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Genotype vs. Phenotype: Genotype refers to an organism's allelic constitution, while phenotype is the observable physical appearance.
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Monohybrid Cross Ratios: In a cross between homozygous dominant and homozygous recessive parents, the F2 generation typically exhibits a 3:1 ratio of dominant to recessive phenotypes and a 1:2:1 ratio of homozygous dominant to heterozygous to homozygous recessive individuals.
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Principle of Dominance: States that in a heterozygote, one allele can conceal the presence of another allele.
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Principle of Segregation: In heterozygotes, different alleles separate during gamete formation, ensuring genetic variability.
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Dihybrid Cross: Investigates two traits at the same time, showcasing interaction between multiple genes.
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Phenotypic Ratios in Dihybrid Crosses: In a classic dihybrid cross, the expected phenotypic ratio in the F2 generation is 9:3:3:1.
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Independent Assortment: Asserts that alleles for different genes segregate independently during gamete formation.
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Test Cross: A cross between an individual with an unknown genotype and a homozygous recessive individual used to determine the unknown genotype.
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Chi-Square Test: A statistical method used to determine whether observed and expected data significantly diverge; critical values reflect the likelihood that deviations are due to chance.
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Degrees of Freedom: Calculated as the number of categories minus one in chi-square tests, this affects the critical value thresholds for significance.
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Human Genetic Study Challenges: Compounded by difficulties in making controlled crosses, obtaining valid family records, and the small number of progeny.
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Pedigree Analysis: Visual tool used for tracking genetic traits through generations, representing affected individuals with colored squares for males and circles for females.
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Binomial Probabilities: Probabilities relating to outcomes in genetics involving two phenotypic classes.
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Test your knowledge with these flashcards based on Genetics Chapter 3. You'll explore key concepts such as true breeding and genetic variation. Perfect for students looking to reinforce their understanding of genetic principles.