Question

Drosophila melanogaster is related to
Linkage
Chromosomal map
Discovery of X-body
Both (1) and (2)

Answer 1

Answer:

693 male progeny, which, when plugged into the equation, produced a result of 37.6. How, then, did Sturtevant explain the deviation?

In short, Sturtevant realized that double recombination events could occur if genes were far apart. Moreover, not only did Sturtevant's data suggest that double-crossing over occurred, but it also suggested that an initial crossover event could inhibit subsequent events by way of a phenomenon Sturtevant referred to as interference.

To understand how Sturtevant arrived at this conclusion, take a look at the data shown in Figure 6 (Sturtevant, 1913). As you can see, Sturtevant examined recombination events between B (body color), CO (two eye color genes that were closely linked), and R (rudimentary wings), and compared the frequencies of crossover events. When B and CO did not separate, Sturtevant noticed that the "gametic ratio," or presence, of CO/R recombinants was approximately 1:2 (3,454:6,972). However, when a crossover between B/CO (N = 60) occurred, there was a much lower likelihood (approximately 1:6.5) of a crossover between CO/R (N = 9). This finding is indicative of interference.

Developing the Chromosome Theory

Genetic Recombination

Gregor Mendel and the Principles of Inheritance

Mendelian Genetics: Patterns of Inheritance and Single-Gene Disorders

Mitosis, Meiosis, and Inheritance

Multifactorial Inheritance and Genetic Disease

Non-nuclear Genes and Their Inheritance

Polygenic Inheritance and Gene Mapping

Sex Chromosomes and Sex Determination

Sex Determination in Honeybees

Test Crosses

METHODS FOR STUDYING INHERITANCE PATTERNS

C. elegans: Model Organism in the Discovery of PKD

Biological Complexity and Integrative Levels of Organization

Genetics of Dog Breeding

Human Evolutionary Tree

Mapping Genes to Chromosomes: Linkage and Genetic Screens

Mendelian Ratios and Lethal Genes

Paternity Testing: Blood Types and DNA

VARIATION IN GENE EXPRESSION

Environmental Influences on Gene Expression

Epistasis: Gene Interaction and Phenotype Effects

Genetic Dominance: Genotype-Phenotype Relationships

Phenotype Variability: Penetrance and Expressivity

Phenotypic Range of Gene Expression: Environmental Influence

Pleiotropy: One Gene Can Affect Multiple Traits