questions in pictures Transcribed Image Text: Sex the flies and note the colour of eyes in all F2 flies. Record the observations in the table

questions in pictures Transcribed Image Text: Sex the flies and note the colour of eyes in all F2 flies.
Record the observations in the table
4. Observations
No. of Flies (Parents for mating)
No. of
Males
Generation
Date of
No. of
Mating
Females
Males
Females
Red
While
Red
While
Eye
Eye
Eye
Eye
Parents
10
10
10
00
00
10
Results after mating
F1
Date of
Date of
Date of
No. of Flies (F1 generation)
separating hatching hatching
for
Adult
for
1st F1
2nd F1
Males
Females
рarent
flies
Batch
Batch
Red
While
Red
While
Eye
Eye
Eye
Eye
Generation
Date of
No. of
No. of
No. of Flies (Parents for mating)
Mating
Males
Females
Males
Females
Red
While
Red
While
Eye
Eye
Eye
Eye
F1
10
10
00
10
10
00
Results after selfing of F1 flies
Date of
F2
Date of
Date of
No. of Flies (F2 generation)
18
separating hatching hatching
for
Adult F1
for
flies
1st F2
2nd F2
Males
Females
Batch
Batch
Red
While
Red
While
Eye
Eye
Eye
Eye
5. Results
F1 Generation
Red eyed female White eyed female
Red eyed male
White eyed male
No. of Flies
Ratio
F2 Generation
Red eyed female White eyed female
Red eyed male
White eyed male
No. of Flies
Ratio
19 Transcribed Image Text: LAB 3. To demonstrate sex-linked inheritance of eye-colour in Drosophila melanogaster.
1. Introduction
If a trait is located on “X” chromosome, the trait would get expressed in alternate sex from one
generation to the other. The inheritance pattern depends on which parent carries the gene on the X
chromosome. The trait or character can be transmitted from father to daughter because X-chromosome
of father is always received by daughter. The trait can be transmitted from mother to son or mother to
daughter because X- chromosome of mother is distributed between both daughter and son. This is called
Cris-Cross inheritance. The recessive trait normally gets expressed in male only since the female carries
a double dose of X chromosome, and therefore she remains a carrier.
2. Requirements:
Drosophila melanogaster cultures (including wild and eye colour mutants), Ether, Binocular
microscope, Food culture bottle, fly etherizer, soft hairbrush, glassware etc.
3. Procedure
3.1. Collecting Virgin Female flies:
Remove all flies from the culture vessel a day before the pupae become ready to hatch (Flies
normally emerge on 11th or 12th day after eggs are laid).
• Check the surface of food for any remaining flies.
• Collect newly emerged adult virgin flies early in the morning, 7:00 am – 8:00 am (flies emerge
in early morning after sunrise and mate within 8 hours).
Anesthetize the flies and drop them on a filter paper.
• Identify the male flies (darker abdomen) and female flies (lighter abdomen) and isolate the
female flies. (Virgin flies are with soft bodies and should be handled with soft hair brush)
• Identify and separate virgin female flies as follows;
a. Virgin female flies have much larger abdomens.
b. Virgin females have a dot on the side of the
c. Females with folded wings and wet must have just emerged and will be virgin.
abdomen.
17
3.2. Crossing mutant flies
Collect 10 white eyed (mutant) virgin females and 10 red eyed (wild type) males.
• Keep them together in a fly culture bottle with food for 7 days.
On eight day, remove all adult flies.
• Check for eggs laid and keep the culture bottle for aside for hatching of
As the flies emerge (12th day after eggs are laid) collect the flies early morning as virgin flies.
This is F1 generation.
Sex the flies and note the colour of eyes in all F1 flies.
In F1 generation, all male flies will be white eyed while all female flies will be red eyed.
Isolate ten males and ten female flies and transfer them into one fly culture bottle with food.
Leave them undisturbed for seven days.
On eight day, remove all adult F1 flies.
Check for eggs laid and keep the culture bottle aside for hatching of eggs.
As the flies emerge (12th day after eggs are laid), collect the flies early morning as virgin flies.
This is F2 generation.
eggs.
18