Fruit Fly

Fruit Fly Questions Name: __Datoya Brown____________

Date: __02/06/2013_________ 

Please print these sheets and then answer all questions prior to the laboratory period. This will help prepare you for the laboratory. Information necessary for answering the questions can be found on Vade Mecum3 and in the Laboratory Manual that is included on the Web application. 1. How can you distinguish an adult male from an adult female Drosophila?  You can distinguish distinguish an adult male form an adult adult female by the fact fact that the males males have have a sex comb, which is a fringe of black bristles on the forelegs. The female’s tip of the abdomen is elongated and pointed and rounded in the males. The females have a seven segmented abdomen whiled the males have five.

2. What are the behaviors an adult male Drosophila exhibits while courting an adult female Drosophila? The male Drosophila will court anything that produces the right taste or smell so while courting a female Drosophila he may sometimes move toward the female head. He will tap her with his forelegs, tasting her is a way to make sure she is the right species. He will then pursue her when she moves extending and vibrating one wing producing the courtship sign.

3. Which is longer, a Drosophila sperm or a Drosophila egg? The Drosophila sperm is longer than the Drosophila egg.

4. What is unusual about the pattern of cleavage in the fruit fly egg compared to that of eggs from organisms such as sea urchin?

The unusual thing about the pattern of cleavage in the fruit fly eggs compared to the other eggs is that it is difficult to see what is going on inside because of the chlorian, the nuclear division occurs multiple before the cytoplasm cleaves.

5. What is the first stage of gastrulation in the fruit fly? The first stage of gastrulation is the infolding of a midventral band of cells.

Name: __Datoya Brown___________

Fruit Fly  – 2

6. How does the fruit fly larva increase its size? The fruit fly larva increases in size by eating everything around the cuticle until it gets full and stops eating. Then it becomes motionless, the mouth hooks and it then begins biting through the old cuticle. With active muscle contractions the larva ruptures and leaves its old cuticle discarding mouthparts that are replaced by new structures of the next larval stage.

7. What structures do the imaginal discs form, and at what point in the life cycle do they differentiate into these structures? The imaginal discs from the epidermal structures such as the legs, eyes, wings, mouthparts and genital ducts. It is during the pupae stage that they differentiate into their adult structures.

8. Can you sex fruit fly larvae, and if so, how? The fruit fly larvae can be sexed based on the gonad size.

9. How does a fruit fly eclose from its pupal case?

A fruit fly ecloses from it pupal case by cracking open the puparium anteriorly and laterally at its seams and emerges from the pupal case.

10. Why are third instar larval salivary glands organs of choice for making chromosome squashes? The third instar larval salivary glands are organs of choice for making chromosome because the discs will be the largest at this stage.