Define the following terms: gene, allele, mutation, locus, trait, character, heredity, true breeding. Define and explain the difference between the following terms: dominant/recess... Define the following terms: gene, allele, mutation, locus, trait, character, heredity, true breeding. Define and explain the difference between the following terms: dominant/recessive; heterozygous/homozygous; genotype/phenotype. Explain how meiosis and random fertilization in sexual reproduction account for the ability of each parent to donate one allele per gene to their offspring. Use a Punnett square to predict the results of a cross (mating) and to state the expected phenotypic and genotypic ratios of the offspring. Explain how independent assortment during meiosis accounts for the independent inheritance of traits specified by genes on different chromosomes. Define and explain how phenotypes in heterozygotes differ with complete dominance, incomplete dominance, and codominance. Define and give examples of pleiotropy and polygenic traits. Define and explain sex-linked traits and how they affect transmission of traits from parents to children. Explain the importance of DNA repair enzymes in protecting cells from UV light. Explain how DNA damage is possible even with properly functioning repair enzymes. Explain how UV exposure can lead to skin problems and cancers. Evaluate the protective effects of sunscreen components to protect yeast cells from UV-induced damage. Write scientifically testable hypotheses and predictions. Analyze and interpret qualitative and quantitative scientific data in graphic and/or numeric form. Determine if results support conclusions based on error bar overlap.
Understand the Problem
The question is asking for comprehensive definitions and explanations of multiple genetic and biological concepts, as well as requests for examples and analyses related to DNA repair, DNA damage, UV exposure, and the use of sunscreen. It requires detailed scientific knowledge and understanding of various biological principles and genetics.
Answer
Basic genetics terms: Gene is a DNA segment, allele is a gene variant. Traits are inherited characteristics. Dominant vs. recessive alleles affect traits. Meiosis, random fertilization ensure genetic diversity.
- Gene: A segment of DNA that encodes a functional product, usually a protein.
- Allele: A variant form of a gene.
- Mutation: A permanent change in the DNA sequence.
- Locus: Specific, fixed position on a chromosome where a particular gene or genetic marker is located.
- Trait: A specific characteristic, such as eye color.
- Character: Heritable feature that varies among individuals, such as flower color.
- Heredity: The passing of traits from parents to offspring.
- True breeding: Organisms that produce offspring of the same variety when they self-pollinate.
- Dominant/Recessive: Dominant alleles mask the effect of recessive alleles in heterozygotes.
- Heterozygous/Homozygous: Heterozygous individuals have two different alleles for a trait while homozygous individuals have identical alleles.
- Genotype/Phenotype: Genotype refers to the genetic makeup, while phenotype refers to observable traits.
- Meiosis and Random Fertilization: During meiosis, homologous chromosomes separate so each gamete receives one allele for each gene. Random fertilization further contributes to genetic variation.
- Independent Assortment: Independent assortment during meiosis results in the independent inheritance of alleles of different genes.
- Complete Dominance, Incomplete Dominance, and Codominance: In complete dominance, the dominant allele completely masks the recessive; in incomplete dominance, the heterozygote phenotype is intermediate; in codominance, both alleles are fully expressed.
- Pleiotropy and Polygenic Traits: Pleiotropy occurs when one gene affects multiple traits; polygenic traits are controlled by two or more genes.
- Sex-linked Traits: Traits that are associated with genes located on sex chromosomes, affecting their inheritance pattern.
- DNA Repair Enzymes and UV Protection: These enzymes fix UV-induced DNA damage, but some damage can still occur. Sunscreen protects against UV-induced damage by blocking or absorbing UV rays.
- Testable Hypotheses and Scientific Data Analysis: Formulate testable scientific hypotheses and analyze scientific data to interpret results.
Punnett squares can predict the phenotypic and genotypic ratios of offspring in genetic crosses, showing patterns like 3:1 in monohybrid crosses for dominant/recessive traits.
Answer for screen readers
- Gene: A segment of DNA that encodes a functional product, usually a protein.
- Allele: A variant form of a gene.
- Mutation: A permanent change in the DNA sequence.
- Locus: Specific, fixed position on a chromosome where a particular gene or genetic marker is located.
- Trait: A specific characteristic, such as eye color.
- Character: Heritable feature that varies among individuals, such as flower color.
- Heredity: The passing of traits from parents to offspring.
- True breeding: Organisms that produce offspring of the same variety when they self-pollinate.
- Dominant/Recessive: Dominant alleles mask the effect of recessive alleles in heterozygotes.
- Heterozygous/Homozygous: Heterozygous individuals have two different alleles for a trait while homozygous individuals have identical alleles.
- Genotype/Phenotype: Genotype refers to the genetic makeup, while phenotype refers to observable traits.
- Meiosis and Random Fertilization: During meiosis, homologous chromosomes separate so each gamete receives one allele for each gene. Random fertilization further contributes to genetic variation.
- Independent Assortment: Independent assortment during meiosis results in the independent inheritance of alleles of different genes.
- Complete Dominance, Incomplete Dominance, and Codominance: In complete dominance, the dominant allele completely masks the recessive; in incomplete dominance, the heterozygote phenotype is intermediate; in codominance, both alleles are fully expressed.
- Pleiotropy and Polygenic Traits: Pleiotropy occurs when one gene affects multiple traits; polygenic traits are controlled by two or more genes.
- Sex-linked Traits: Traits that are associated with genes located on sex chromosomes, affecting their inheritance pattern.
- DNA Repair Enzymes and UV Protection: These enzymes fix UV-induced DNA damage, but some damage can still occur. Sunscreen protects against UV-induced damage by blocking or absorbing UV rays.
- Testable Hypotheses and Scientific Data Analysis: Formulate testable scientific hypotheses and analyze scientific data to interpret results.
Punnett squares can predict the phenotypic and genotypic ratios of offspring in genetic crosses, showing patterns like 3:1 in monohybrid crosses for dominant/recessive traits.
More Information
Meiosis and random fertilization create unique genetic combinations in offspring, contributing to genetic diversity. Punnett squares are tools used to visualize genetic crosses and predict offspring ratios.
Tips
Common mistake: Confusing genotype with phenotype. Genotype is the genetic makeup, while phenotype is the observable characteristic.
Sources
- Genes and genetics explained - Better Health Channel - betterhealth.vic.gov.au
- 8.2 Laws of Inheritance – Concepts of Biology - opentextbc.ca
- Define the following terms: gene, allele, dominant, recessive ... - Vaia - vaia.com
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