Genetics-And-Evolution-Principles-Of-Inheritance-And-Variation-3
Dihybrid Cross
1. Two Traits Studied: Involves inheritance of two different traits.
2. Alleles: Each trait has two alleles (dominant and recessive).
3. Independent Assortment: Traits inherited independently of each other.
4. Parental Genotypes: Identify genotypes of two parental organisms.
5. Gametes: Determine possible gametes for each trait.
6. Punnett Square: Use a 4x4 Punnett square to predict offspring genotypes.
7. Genotypic/Phenotypic Ratios: Analyze the Punnett square for these ratios.
8. Results Interpretation: Understand the inheritance patterns of traits.
Parents in Genetics
1. Genetic Material Transfer: Each parent contributes half of the genetic material.
2. Alleles: Parents can be homozygous or heterozygous.
3. Phenotype Influence: Parents’ genotypes determine phenotypes.
4. Dominant/Recessive Traits: Influence offspring’s traits.
5. Mendelian Genetics: Principles apply in trait inheritance.
Gametes
1. Haploid Cells: Carry half the chromosome number.
2. Types: Sperm and egg.
3. Meiosis: Process for gamete formation.
4. Genetic Diversity: Ensured through genetic recombination.
5. Fertilization: Combines genetic material from both parents.
Phenotypic Ratio
1. Trait Observation: Ratio of different observable traits in offspring.
2. Mendelian Inheritance: Often follows specific patterns like 3:1 or 9:3:3:1.
3. Varies by Dominance: Different in complete dominance, incomplete dominance, and codominance.
Dihybrid Test Cross
1. Determines Unknown Genotypes: Crosses an unknown genotype with a homozygous recessive.
2. Offspring Phenotypes: Analyzed to infer the unknown genotype.
3. Phenotypic Ratios: Indicate the likelihood of certain genotypes.
Dihybrid Back Cross
1. Examines Two Traits: Crosses a dihybrid organism with a homozygous recessive.
2. Offspring Analysis: Helps understand how traits are inherited and assorted.