Textbook Question
Compare and contrast the following terms:
Genotype and Phenotype
1
views
Ch. 2 - Transmission Genetics
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - The Molecular Basis of Heredity, Variation, and Evolution64
- Ch. 2 - Transmission Genetics144
- Ch. 3 - Cell Division and Chromosome Heredity81
- Ch. 4 - Gene Interaction87
- Ch. 5 - Genetic Linkage and Mapping in Eukaryotes103
- Ch. 6 - Genetic Analysis and Mapping in Bacteria and Bacteriophages73
- Ch. 7 - DNA Structure and Replication71
- Ch. 8 - Molecular Biology of Transcription and RNA Processing79
- Ch. 9 - The Molecular Biology of Translation110
- Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization100
- Ch. 11 - Gene Mutation, DNA Repair, and Homologous Recombination86
- Ch. 12 - Regulation of Gene Expression in Bacteria and Bacteriophage90
- Ch. 13 - Regulation of Gene Expression in Eukaryotes38
- Ch. 14 - Analysis of Gene Function via Forward Genetics and Reverse Genetics72
- Ch. 15 - Recombinant DNA Technology and Its Applications69
- Ch. 16 - Genomics: Genetics from a Whole-Genome Perspective49
- Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes27
- Ch. 18 - Developmental Genetics43
- Ch. 19 - Genetic Analysis of Quantitative Traits66
- Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels105
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
Chapter 2, Problem 1a
Compare and contrast the following terms:
Dominant and Recessive
Verified step by step guidance1
Understand the definitions: A dominant allele is one that expresses its trait in the phenotype even when only one copy is present (heterozygous condition). A recessive allele, on the other hand, only expresses its trait in the phenotype when two copies are present (homozygous condition).
Consider the genetic notation: Dominant alleles are typically represented by uppercase letters (e.g., 'A'), while recessive alleles are represented by lowercase letters (e.g., 'a').
Examine inheritance patterns: In a heterozygous individual (e.g., genotype 'Aa'), the dominant allele will mask the expression of the recessive allele, resulting in the dominant phenotype.
Relate to real-world examples: For instance, in pea plants, the allele for tall height (T) is dominant, while the allele for short height (t) is recessive. A plant with the genotype 'Tt' will be tall because the dominant allele (T) is expressed.
Summarize the key difference: Dominant alleles require only one copy to influence the phenotype, while recessive alleles require two copies to be expressed in the phenotype.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Dominant Alleles
Dominant alleles are variants of a gene that express their traits even when only one copy is present in the genotype. This means that if an individual has at least one dominant allele for a trait, that trait will be observed in the phenotype. For example, in pea plants, the allele for tall stems (T) is dominant over the allele for short stems (t), so a plant with either TT or Tt will be tall.
Recommended video:
Guided course
04:37
Variations on Dominance
Recessive Alleles
Recessive alleles are gene variants that only express their traits when two copies are present in the genotype. If an individual has only one recessive allele, the dominant allele will mask its effect, and the recessive trait will not be observed in the phenotype. Using the same pea plant example, a plant must have the genotype tt to exhibit the short stem trait, as the presence of a dominant T allele would prevent this.
Recommended video:
Guided course
03:03New Alleles and Migration
Mendelian Inheritance
Mendelian inheritance refers to the patterns of inheritance first described by Gregor Mendel, which include the principles of dominance and recessiveness. According to these principles, traits are determined by alleles that segregate during gamete formation, leading to predictable ratios of dominant and recessive traits in offspring. This foundational concept in genetics helps explain how traits are passed from parents to offspring and is crucial for understanding genetic variation.
Recommended video:
Guided course
05:13Organelle Inheritance