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Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYPrinciples of Inheritance and Variation4 Marks
Question
What is the cause of frameshift mutation?
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Answer

Deletions and insenions of base pairs of DNA cause frameshift mutation.

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Read the following and answer any four questions from $2(i)$ to $2(v)$ given below: Restriction endonuclease was isolated for the first ti me by W. Arb er in $1962$ in bacteria. Restriction endonucleases cut the DNA duplex at specific points therefore they are also called as molecular scissors or biological scissors. Three types of restriction endonucleases are Type I, Type II and Type III but only Type II restriction endonucleases are used in recombinant DNA technology. Restriction endonuclease EcoR I recognises the base sequence GAATTC in DNA duplex and cut strands between G and A.
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  1. ATP is not required for cleaving.
  2. It consists of three different subunits.
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  1. Restriction endonuclease was isolated for the first time in a:
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  2. Animal cell.
  3. Prokaryotic cell.
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  1. Restriction endonucleases are also called as molecular or biological scissors because,
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  3. $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \downarrow\\5'-\text{GAATTC}-3'\\3'-\text{CTTAAG}-5'\\\ \ \ \ \ \ \ \ \ \uparrow$
  4. $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \downarrow\\5'-\text{GAATTC}-3'\\3'-\text{CTTAAG}-5'\\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \uparrow$
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S. No
A
B
(a)
Cellular endosperm
Free- nuclear endosperm
(b)
Free-nuclear endosperm
Cellular endosperm
(c)
Helobial endosperm
Cellular endosperm
(d)
Free-nuclear endosperm
Helobial endosperm
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V
W
X
(a)
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Zona pellucida
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(b)
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Corona radiata
Zona pellucida
(c)
Cortical granules
Plasma membrane
Corona radiata
(d)
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Corona radiata
Zona pellucida
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