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4.Principles of Inheritance and Variation
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Polytene chromosomes in salivary glands of Drosophila are formed as a result of
A
Endoduplication
B
Duplication without separation
C
Replication of $DNA$ without cell division
D
All the above
Solution
(d)The chromosome is formed by somatic pairs between homologous chromosomes and repeated replication or endomitosis of chromonemata.
Standard 12
Biology
Similar Questions
In Drosophila, the allele for a normal grey body colour $G$ is dominant to ebony body $g.$ The following table summarises the results of several crosses
| S.No | Cross | Result |
| $I.$ | Strain $1 \times$ gg | All wild type |
| $II.$ | Strain $2 \times$ gg |
$1$ wild type $:\;1$ ebony |
| $III.$ | Strain $3 \times$ gg | All ebony |
| $IV.$ | Strain $4 \times$ Gg |
$3$ wild type $:\,1$ ebony |
Which strains both have the genotype Gg?
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