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Questions and Answers
What did Gregor Mendel primarily study in his experiments?
What did Gregor Mendel primarily study in his experiments?
Mendel's work was widely recognized and celebrated during his lifetime.
Mendel's work was widely recognized and celebrated during his lifetime.
False
What are the two types of alleles related to a particular characteristic?
What are the two types of alleles related to a particular characteristic?
Homozygous and Heterozygous
A _______ is a fixed location on a strand of DNA where a gene or one of its alleles is located.
A _______ is a fixed location on a strand of DNA where a gene or one of its alleles is located.
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Match the following genetic terms with their definitions:
Match the following genetic terms with their definitions:
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Which process is described as new combinations of genes in sexual reproduction?
Which process is described as new combinations of genes in sexual reproduction?
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Homologous chromosomes contain unique genes that do not pair with each other.
Homologous chromosomes contain unique genes that do not pair with each other.
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What was the name of Mendel's published work?
What was the name of Mendel's published work?
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What is the principle of independent assortment?
What is the principle of independent assortment?
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Incomplete dominance results in a phenotype that is either dominant or recessive.
Incomplete dominance results in a phenotype that is either dominant or recessive.
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What phenotypic ratio is observed in the F2 generation when pink snapdragons are self-pollinated?
What phenotypic ratio is observed in the F2 generation when pink snapdragons are self-pollinated?
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The principle of _____ states that genes become separated during gamete formation.
The principle of _____ states that genes become separated during gamete formation.
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Match the following concepts with their definitions:
Match the following concepts with their definitions:
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What is the term for the allele that masks the expression of an alternate allele?
What is the term for the allele that masks the expression of an alternate allele?
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A recessive allele appears in the phenotype when in a heterozygous condition.
A recessive allele appears in the phenotype when in a heterozygous condition.
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What does the term 'phenotype' refer to?
What does the term 'phenotype' refer to?
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In a monohybrid cross, parents differ by a single ______.
In a monohybrid cross, parents differ by a single ______.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What would the genotype of a homozygous tall plant be?
What would the genotype of a homozygous tall plant be?
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All offspring from the cross PP × pp will be heterozygous.
All offspring from the cross PP × pp will be heterozygous.
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Using a Punnett square allows you to predict the ______ and ______ of the offspring.
Using a Punnett square allows you to predict the ______ and ______ of the offspring.
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Study Notes
Introduction to Genetics
- Genetics is the branch of biology studying heredity and variation in organisms.
- Chromosomes contain hereditary information in the form of genes.
- Genes are sequences of DNA that encode proteins.
- Chromosomes (and genes) exist in pairs.
- New combinations of genes occur during sexual reproduction through fertilization from two parents.
Gregor Mendel
- Gregor Mendel, an Austrian monk, studied heredity using pea plants.
- Mendel's work involved controlled crosses of pea plants to study inheritance patterns.
- Mendel showed that heredity is not a "blending" process but follows specific patterns.
- He experimented with seven traits of pea plants.
- In 1866, Mendel published his findings.
- His work was initially overlooked, but later rediscovered and recognized as seminal work in genetics.
Mendel's Principles
- Principle of Dominance: One allele can mask the expression of another.
- Principle of Segregation: During gamete formation, the paired hereditary factors (genes) separate, ensuring each sex cell receives only one gene.
- Principle of Independent Assortment: Members of one gene pair separate independently from other pairs during gamete formation. This leads to various combinations of traits in offspring.
Monohybrid and Dihybrid Crosses
- Monohybrid crosses investigate the inheritance of a single trait.
- Dihybrid crosses explore the inheritance of two separate traits.
- These crosses support the principles of segregation and independent assortment.
- Monohybrid crosses often involve parental generations (P generation) and first, or filial generation (F1 generation).
Punnett Square
- A Punnett square is a tool to predict genotypes and phenotypes of offspring.
- It visually represents the possible combinations of alleles in offspring resulting from a genetic cross.
Beyond Mendelian Genetics – Incomplete Dominance
- Incomplete dominance occurs when the heterozygous phenotype is intermediate between the two homozygous phenotypes.
- For example, in snapdragons, a cross between a red flower and a white flower produces pink flowers. This shows incomplete dominance.
- The F1 generation consists of offspring exhibiting an intermediate phenotype (e.g., pink flowers).
- When the F1 generation is self-pollinated, the F2 generation displays a 1:2:1 ratio of red, pink, and white flowers.
Genetic Terms
- Gene: A unit of heredity, a section of DNA encoding a single protein.
- Genome: The complete set of genes in an organism.
- Alleles: Different versions of a gene.
- Homozygous: Having identical alleles for a particular gene.
- Heterozygous: Having different alleles for a particular gene.
- Dominant: An allele that masks the expression of another.
- Recessive: An allele whose expression is masked by another.
- Genotype: The genetic makeup of an organism, describing the specific alleles present.
- Phenotype: The physical appearance of an organism, resulting from the interaction between genotype and environment.
- Locus: The specific fixed location of a gene or allele on a chromosome.
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Description
This quiz covers the foundational concepts of genetics, focusing on heredity and variation in organisms. You'll explore Gregor Mendel's groundbreaking work with pea plants and understand his principles of inheritance. Test your knowledge on essential genetic terms and Mendel's contributions to the field.
