Genetics-i Miscellaneous
Direction: The abdomen length (in millimeters) was measured in 15 male fruit flies, and the following data were obtained :
1.9, 2.4, 2.1, 2.0, 2.2, 2.4, 1.7, 1.8, 2.0, 2.0, 2.3, 2.1, 1.6, 2.3 and 2.2.
- The value of standard deviation (SD) will be
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We know, Standard deviation, S.D. = √(Variance) = √σ²
Now, Variance = 0.061 (from previous question)
Hence, Standard deviation = √(0.061) = 0.25 (approx.)Correct Option: B
We know, Standard deviation, S.D. = √(Variance) = √σ²
Now, Variance = 0.061 (from previous question)
Hence, Standard deviation = √(0.061) = 0.25 (approx.)
- In transgenics, alterations in the sequence of uncleotide in genes are due to
P. Substitution
Q. Deletion
R. Insertion
S. Rearrangement
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Transgenics is based on insertion of foreign genes from a different species, or deletion of existing nucleotides from the gene sequence in normal host cells. Also substitution of bases by transition( Pu by Pu/ Py by Py) or transversion( Pu replaced by Py of vice-versa). Usually, the process of random gene rearrangement is not included in transgenic experiments, because it is a natural process not yielding desired transgenic traits. Thus, in actual practice, insertion, deletion and/or substitution is used for yielding transgenics.
Correct Option: B
Transgenics is based on insertion of foreign genes from a different species, or deletion of existing nucleotides from the gene sequence in normal host cells. Also substitution of bases by transition( Pu by Pu/ Py by Py) or transversion( Pu replaced by Py of vice-versa). Usually, the process of random gene rearrangement is not included in transgenic experiments, because it is a natural process not yielding desired transgenic traits. Thus, in actual practice, insertion, deletion and/or substitution is used for yielding transgenics.
- True breeding Drosophila flies with curved wings and dark bodies were mated with true breeding short wings and tan body Drosophila. The F1 progeny was observed to be with curved wings and tan body. The F1 progeny was again allowed to breed and
produced flies of the following phenotype, 45 curved wings tan body, 15 short wings tan body, 16 curved wings dark body and, 6 short wings dark body.
The mode of inheritance is
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Let us denote the dominant curved wings allele by C, short wings by c, tan body by D, dark body by d. Assumption is made that curved wings and tan body are recessive traits and that they follow Mendelian genetics.
Now, Fsub>1 progeny CcDd (Since, Fsub>1 progeny was observed to be with curved wings and tan body)
Cross breed → CcDd X CcDdf , progency → C C D D / C c D d / C C D d / C c D D c c D D / ccD d C c d d / C C dd ccdd (45) (15) (16) (6) 9 : 3 : 3.3 : 1.2
which approximately becomes 9 : 3 : 3 : 1, which is the phenotypic ratio of F2 generation according to Mendelian genetics
Correct Option: A
Let us denote the dominant curved wings allele by C, short wings by c, tan body by D, dark body by d. Assumption is made that curved wings and tan body are recessive traits and that they follow Mendelian genetics.
Now, Fsub>1 progeny CcDd (Since, Fsub>1 progeny was observed to be with curved wings and tan body)
Cross breed → CcDd X CcDdf , progency → C C D D / C c D d / C C D d / C c D D c c D D / ccD d C c d d / C C dd ccdd (45) (15) (16) (6) 9 : 3 : 3.3 : 1.2
which approximately becomes 9 : 3 : 3 : 1, which is the phenotypic ratio of F2 generation according to Mendelian genetics
- Some of the genes from viruses introduced into plants in fully functional form often exhibit Mendelian inheritance because
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Mendelian inheritance is observed as the viral genes have been stably integrated and thus expresses itself.
Correct Option: A
Mendelian inheritance is observed as the viral genes have been stably integrated and thus expresses itself.
