नमस्कार विद्यार्थी मित्रांनो To study wing shape and eye colour in Drosophila हे प्रॅक्टिकल Experiments to be performed - PART A मधील आहे. याचाच अर्थ तुम्हाला हे प्रॅक्टिकल Exam मध्ये Examiner ला Performe करून दाखवायचे आहे. म्हणूनच प्रॅक्टिकल Exam च्या दृष्टीने हे Experiment अतिशय महत्त्वाचे आहे. या ब्लॉग मध्ये आपण Practical Book मधील या Experiment Number - 11 ची उत्तरे पाहणारं आहोत. ही उत्तरे काळजीपूर्वक वाचून आपल्या Practical Book मध्ये लिहा किंवा तुमच्या कॉलेजमधील संबंधित विषय शिक्षकांची मदत घ्या.
11. To study wing shape and eye colour in Drosophila.
Aim :- To study the genetic variation of traits in Drosophila melanogaster.
Requirements :- Glass jar, petri dish, banana pieces, Muslin cloth, bell jar, slide, cover slips, graded series of alcohol, xylene, DPX, etc.
Figure :-
I. Preparation of culture beds:
1. Peel the ripe banana fruit. Discard the skin and mash the fruit into a soupy pulp.
2. Take a clean sterilized glass jar or petridish and place the banana pulp in it.
3. Add a few grains of yeast.
4. Keep a small blotting paper to absorb excess moisture from the pulp and also to provide substratum for pupation of the larvae.
5. Many culture beds can be prepared by the above method for the different varieties of fruit fly.
II. The culturing of Drosophila:
6. The pulp in the culture beds attracts the Drosophila. Cover the culture beds with a bell jar after the Drosophila have reached the pulp. They complete their life cycle within 48 hours.
7. Capture the Drosophila and fix it into 70% alcohol.
8. Process the Drosophila flies through 70%, 90% and 100% graded series of ethyl alcohol for 10 minutes each.
9. Place Drosophila in Xylene for 5 min. and clear it properly.
10. Mount it on a glass slide with DPX and observe under the microscope.
Observation and Result :-
| Eye Color | Pattern of Wing | No. of segments in a leg | |
|---|---|---|---|
| Culture 1 | Red(wild) | Normal | Nine number of segments |
| Culture 2 | Black(mutant) | Vestigial | Less number |
Questions
1. Why T.H. Morgan used Drosophila melanogaster in his genetic experiments?
Ans :- Morgan used Drosophila melanogaster in his genetic experiments because fruit flies have a short life cycle, allowing researchers to study genetic traits across multiple generations in a brief period. They also reproduce rapidly and produce numerous offspring, making it easier to observe inheritance patterns and genetic variations.
2. What are the difference between male and female Drosophila?
Ans :- The difference between male and female Drosophila is that females have a pointed abdomen with a spike on the dorsal surface at the rear, and fewer visible structures. Males, on the other hand, have a rounded abdomen with more complex structures visible on the ventral surface.
3. What is linkage?
Ans :- Linkage refers to the physical association of genes that are inherited together rather than independently.
4. What kind of eye colour and pattern of wing is present in wild fruit fly?
Ans :- In wild fruit flies, the typical eye color is dull red, and their wings are flat and wide.
5. Is the inheritance of wing type/eye colour in drosophila-multigenic or multiallelic.
Ans :- The inheritance of wing type and eye color in Drosophila is multigenic.
Multiple Choice Questions
1. The mechanism of sex determination in Drosophila is...
a. XX - XO type
b. XX - XY type
c. ZZ - ZW type
d. XX - ZZ type
Ans :- b. XX - XY type
2. How many different alleles are seen in the wing series of Drosophila?
a. 3
b. 6
c. 5
d. 4
Ans :- c. 5
3. How many pairs of chromosomes are present in somatic cell of Drosophila?
a. 7
b. 8
c. 12
d. 4
Ans :- d. 4
4. The wing shape in Drosophila is an example of...
a. Co - dominance
b. Multiple alleles
c. Pleiotropy
d. incomplete dominance
Ans :- b. Multiple alleles
5. How many linkage groups do occur in female Drosophila?
a. 4
b. 8
c. 2
d. 7
Ans :- a. 4
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