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Questions and Answers
What is the difference between a gene and an allele?
What is the difference between a gene and an allele?
A gene is a stretch of DNA or RNA that determines a certain trait, while an allele is one of the alternative forms of a gene.
What is the difference between phenotype and genotype?
What is the difference between phenotype and genotype?
Genotype is the genetic makeup of an organism, while phenotype is the physical characteristics.
What is the difference between a dominant and a recessive allele?
What is the difference between a dominant and a recessive allele?
A dominant allele masks the expression of an alternative gene and appears in the heterozygous condition, while a recessive allele is masked by the dominant allele and appears only in homozygous condition.
Who was Gregor Mendel and why is he famous?
Who was Gregor Mendel and why is he famous?
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What were Mendel's experiments and what data did he collect from them?
What were Mendel's experiments and what data did he collect from them?
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Why did Mendel select pea plants for his experiments?
Why did Mendel select pea plants for his experiments?
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What do the terms heterozygous and homozygous mean?
What do the terms heterozygous and homozygous mean?
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Why do we have to specify 'dominant' or 'recessive' with homozygous but not heterozygous?
Why do we have to specify 'dominant' or 'recessive' with homozygous but not heterozygous?
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What is a Punnett Square?
What is a Punnett Square?
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What is a monohybrid cross?
What is a monohybrid cross?
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What do we mean by 'complex' inheritance or 'non-Mendelian' inheritance?
What do we mean by 'complex' inheritance or 'non-Mendelian' inheritance?
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What is the law of independent assortment?
What is the law of independent assortment?
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What is the Law of Segregation?
What is the Law of Segregation?
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What is the rule of dominance?
What is the rule of dominance?
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What is the difference between codominant and incomplete dominant inheritance?
What is the difference between codominant and incomplete dominant inheritance?
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What is X-linked inheritance?
What is X-linked inheritance?
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A dominant allele/trait is one that always shows up more often in a population.
A dominant allele/trait is one that always shows up more often in a population.
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An allele is the same as a gene, but merely a different version of the gene.
An allele is the same as a gene, but merely a different version of the gene.
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A genotype is the physical expression of the DNA an organism shows.
A genotype is the physical expression of the DNA an organism shows.
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Genetics is the branch of biology that involves the study of how different traits are transmitted from one generation to the next.
Genetics is the branch of biology that involves the study of how different traits are transmitted from one generation to the next.
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For F = furry and f = non-furry; a homozygous dominant and a homozygous recessive parent will always have furry children.
For F = furry and f = non-furry; a homozygous dominant and a homozygous recessive parent will always have furry children.
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Punnett Squares show that it only takes having 4 offspring to come up with all possible combinations of alleles.
Punnett Squares show that it only takes having 4 offspring to come up with all possible combinations of alleles.
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The law of independent assortment states that ALL traits are inherited separately from one another.
The law of independent assortment states that ALL traits are inherited separately from one another.
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What is a stretch of DNA that determines a certain trait?
What is a stretch of DNA that determines a certain trait?
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The _________ is the physical expression of traits.
The _________ is the physical expression of traits.
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When an organism has two different alleles for the same gene, it is called:
When an organism has two different alleles for the same gene, it is called:
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Parents that breed and are the same except for one trait would create a:
Parents that breed and are the same except for one trait would create a:
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Which of the following is an example of a homozygous recessive individual?
Which of the following is an example of a homozygous recessive individual?
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Which of the following is an example of a heterozygous individual?
Which of the following is an example of a heterozygous individual?
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For cats, B = black fur and b = white fur. A heterozygous parent mates with a homozygous recessive parent. What are the odds that their kitten is a heterozygote?
For cats, B = black fur and b = white fur. A heterozygous parent mates with a homozygous recessive parent. What are the odds that their kitten is a heterozygote?
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For B = black fur and b = white fur: Cross BB with Bb; what is the accurate phenotype ratio?
For B = black fur and b = white fur: Cross BB with Bb; what is the accurate phenotype ratio?
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A blue fish mates with a red fish and creates a purple-colored offspring. In these fish, color is inherited in what way?
A blue fish mates with a red fish and creates a purple-colored offspring. In these fish, color is inherited in what way?
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What do the letters on the inside of a Punnett Square represent?
What do the letters on the inside of a Punnett Square represent?
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The specific location of a gene/DNA sequence is called a(n)?
The specific location of a gene/DNA sequence is called a(n)?
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The study of heredity is called:
The study of heredity is called:
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Who is the father of genetics?
Who is the father of genetics?
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Gregor Mendel concluded that traits are:
Gregor Mendel concluded that traits are:
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Hair color and eye color are examples of a person's:
Hair color and eye color are examples of a person's:
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The principles of probability can be used to:
The principles of probability can be used to:
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A couple has 2 children, both of whom are boys. What is the chance that the parent's next child will be a boy?
A couple has 2 children, both of whom are boys. What is the chance that the parent's next child will be a boy?
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Genes located on homologous chromosomes may have alternate forms that control different forms of a trait. These alternate forms of a gene are called:
Genes located on homologous chromosomes may have alternate forms that control different forms of a trait. These alternate forms of a gene are called:
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If an individual possesses two recessive alleles for the same trait, the individual is said to be:
If an individual possesses two recessive alleles for the same trait, the individual is said to be:
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If a pea plant were homozygous recessive for height, how would its alleles be represented?
If a pea plant were homozygous recessive for height, how would its alleles be represented?
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When an organism has two alleles for a particular trait that are different, the organism is called:
When an organism has two alleles for a particular trait that are different, the organism is called:
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A genetic trait that appears in every generation of offspring is called:
A genetic trait that appears in every generation of offspring is called:
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The term for a cross that involves just one trait, such as pod shape, is called:
The term for a cross that involves just one trait, such as pod shape, is called:
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When Gregor Mendel crossed homozygous purple-flowered plants with homozygous white-flowered plants, all the offspring were purple because:
When Gregor Mendel crossed homozygous purple-flowered plants with homozygous white-flowered plants, all the offspring were purple because:
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In Mendel's garden pea experiment, he allowed each variety of garden pea to self-pollinate for several generations to produce the original parents or:
In Mendel's garden pea experiment, he allowed each variety of garden pea to self-pollinate for several generations to produce the original parents or:
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When Gregor Mendel crossed a homozygous tall plant with a homozygous short plant, the F1 plants inherited:
When Gregor Mendel crossed a homozygous tall plant with a homozygous short plant, the F1 plants inherited:
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Mendel's law of segregation states that:
Mendel's law of segregation states that:
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The phenotype of an organism is:
The phenotype of an organism is:
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A dog's phenotype can be determined by:
A dog's phenotype can be determined by:
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Which of the following describes an organism that has the phenotype Bb?
Which of the following describes an organism that has the phenotype Bb?
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An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring. These offspring are likely to be:
An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring. These offspring are likely to be:
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Tallness (T) is dominant over shortness (t) in pea plants. Which of the following represents the genotype of a pea plant that is heterozygous for tallness?
Tallness (T) is dominant over shortness (t) in pea plants. Which of the following represents the genotype of a pea plant that is heterozygous for tallness?
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Mendel's finding that the inheritance of one trait had no effect on the inheritance of another became known as the:
Mendel's finding that the inheritance of one trait had no effect on the inheritance of another became known as the:
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A useful device for predicting the possible offspring of crosses between different genotypes is the:
A useful device for predicting the possible offspring of crosses between different genotypes is the:
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The _______ produced by each parent are shown along the sides of a Punnett square.
The _______ produced by each parent are shown along the sides of a Punnett square.
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What do the letters inside the grid of the Punnett square represent?
What do the letters inside the grid of the Punnett square represent?
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A female guinea pig homozygous dominant for black fur color is mated with a male homozygous for white fur color. In a litter of eight offspring, there would probably be:
A female guinea pig homozygous dominant for black fur color is mated with a male homozygous for white fur color. In a litter of eight offspring, there would probably be:
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In mink, brown fur color is dominant to silver-blue fur color. If a homozygous brown mink is mated with a silver-blue mink and 8 offspring are produced, how many would be expected to be silver-blue?
In mink, brown fur color is dominant to silver-blue fur color. If a homozygous brown mink is mated with a silver-blue mink and 8 offspring are produced, how many would be expected to be silver-blue?
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The unknown genotype of an individual with a dominant phenotype can be determined using:
The unknown genotype of an individual with a dominant phenotype can be determined using:
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If a characteristic is sex-linked, it occurs only in females or males.
If a characteristic is sex-linked, it occurs only in females or males.
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Since the allele for colorblindness is located on the X chromosome, colorblindness is sex-linked.
Since the allele for colorblindness is located on the X chromosome, colorblindness is sex-linked.
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Which of the following describes hemophilia?
Which of the following describes hemophilia?
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Study Notes
Genetics Terminology
- Gene: A segment of DNA or RNA that determines a specific trait; can have multiple forms known as alleles.
- Allele: Alternative forms of a gene; for instance, eye color has several alleles (e.g., blue or brown).
- Genotype: The genetic composition of an organism, while phenotype refers to its observable physical characteristics.
Dominance and Inheritance
- Dominant Allele: Masks the expression of a recessive allele; shows in both homozygous and heterozygous conditions.
- Recessive Allele: Only expressed in homozygous conditions; masked by dominant alleles.
- Heterozygous: An organism with two different alleles for the same gene.
- Homozygous: An organism with identical alleles for a specific gene.
Mendel’s Contributions
- Gregor Mendel: Conducted experiments with pea plants, establishing foundational principles of heredity, such as dominance and segregation.
- Mendel’s Laws: Include the Law of Segregation (two alleles for a trait separate during gamete formation) and the Law of Independent Assortment (genes segregate independently).
Punnett Squares and Genetic Crosses
- Punnett Square: A tool for predicting offspring traits based on parental genotypes, indicating possible combinations of alleles.
- Monohybrid Cross: Involves one trait; contrasts one characteristic between two organisms.
- Dihybrid Cross: Involves two traits; compares two characteristics simultaneously.
Patterns of Inheritance
- Codominance: Both alleles in a heterozygous individual contribute equally to the phenotype (e.g., a blue fish crossed with a red fish produces purple offspring).
- Incomplete Dominance: Neither allele is dominant, resulting in a blended phenotype.
X-linked Inheritance
- X-linked Traits: Traits controlled by genes located on the X chromosome; can manifest differently in males and females, crucial for identifying inheritance patterns.
Genetic Probability
- Probability: The principles of probability apply to predict the likelihood of traits in offspring based on their genotypes.
- Phenotypic Ratios: The expected proportion of different phenotypes in offspring based on genetic crosses.
Special Traits
- Sex-Linked Traits: Such as colorblindness and hemophilia, which occur due to alleles on the sex chromosomes and often show different patterns in males and females.
- Test Cross: A method used to determine the genotype of an organism with a dominant phenotype by crossing it with a homozygous recessive individual.
Key Genotypes and Phenotypes
- Homozygous Recessive Example: Represented as "aa."
- Heterozygous Example: Represented as "AB" or "Tt" for tallness.
- Genetic Outcome Example: A cross between a heterozygous parent and a homozygous recessive parent results in a variety of offspring phenotypes.
Importance of Genetics
- Genetics: The study of heredity and how traits are passed from parents to offspring, influencing biodiversity and inheritance patterns in populations.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge with these flashcards from Unit 8 of your science curriculum. This quiz covers essential genetic concepts such as genes, alleles, phenotypes, and genotypes. Perfect for reviewing before a test or reinforcing your understanding of genetics.
