Based on the Experiment in Which Drosophila Flies Were Raised

question 130

Multiple Choice

Based on the experiment in which Drosophila flies were raised at a higher than normal oxygen concentration, which of the following statements is most likely true?

• A) Fly body size is constrained because there are not enough alleles that increase body size.
• B) Fly body size is constrained because alleles that increase body size are selected against at normal oxygen levels.
• C) At normal oxygen concentration levels, fly body size is under strong directional selection.
• D) Fly body size would likely increase if flies were raised at lower than normal oxygen concentrations.
• E) Increased oxygen levels appear to have little effect on fly body size, even after many generations.

---

Definitions:

Anaphase I

A stage in the first division of meiosis where homologous chromosomes are separated and move to opposite ends of the cell.

Somatic Cell

Body cell; excludes cells that undergo meiosis and become sperm or eggs.

Chromosomes

Threadlike structures composed of DNA and proteins, containing the genetic information necessary for cell growth, division, and function.

Meiosis

A specialized type of cell division that reduces the chromosome number by half, leading to the production of haploid gametes in sexually reproducing organisms.