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question_answer1)
The evidence that crossing over occurs at four stranded stage and not at two stranded stage of the chromosomes, comes from [DPMT 1993]
A)
2 : 2 : 2 : 2 arrangement of ascospores in Neurospora done
clear
B)
4 : 4 arrangement of ascospores in Neurospora done
clear
C)
Studies of meiosis in maize done
clear
D)
Studies on linkage maps of chromosomes in Drosophila done
clear
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question_answer2)
Mendel did not recognize the linkage phenomenon in his experiments because [CMC Vellore 1993]
A)
There were many chromosomes to handle done
clear
B)
Characters he studied were located on different chromosomes done
clear
C)
He did not have powerful microscope done
clear
D)
He studied only pure plants done
clear
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question_answer3)
Coupling and repulsion are the two faces of [JIPMER 1994]
A)
Crossing over done
clear
B)
Linkage done
clear
C)
Chiasmata done
clear
D)
Mutation done
clear
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question_answer4)
The map distance between genes A and B is 3 units, between B and C 10 units and between C and A 7 units. The order of the genes in a linkage map constructed on the above data would perhaps be [CMC Vellore 1994]
A)
A, B, C done
clear
B)
A, C, B done
clear
C)
B, C, A done
clear
D)
B, A, C done
clear
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question_answer5)
Alleles of different genes that are on the same chromosome may occasionally be separated by a phenomenon known as [MP PMT 1993]
A)
Pleotropy done
clear
B)
Epistasis done
clear
C)
Continuous variation done
clear
D)
Crossing over done
clear
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question_answer6)
Which one of the following pairs is correctly matched [MP PMT 1993]
A)
Morgan Discovered the process of linkage done
clear
B)
Linus Pauling Isolated DNA for the first time done
clear
C)
Francis Crick Discovered the phenomenon of transformation done
clear
D)
H. Khorana Discovered that a sequence of 3 nucleotides codes for a single amino acid done
clear
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question_answer7)
The percentage of crossing over will be more if
A)
Linked genes are located far apart from each other done
clear
B)
Linked genes are located close to each other done
clear
C)
Genes are not linked done
clear
D)
Genes are located in a different cell done
clear
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question_answer8)
Drosophila has four pairs of chromosomes. How many linkage groups does it have
A)
Eight done
clear
B)
Four done
clear
C)
One less than the pairs of chromosomes done
clear
D)
One more than the pairs of chromosomes done
clear
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question_answer9)
Linkage in Drosophila was first discovered by
A)
Morgan done
clear
B)
Bateson and Punnet done
clear
C)
Sturtevant done
clear
D)
Bridges done
clear
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question_answer10)
Chiasmata firstly seen in [RPMT 1995; MP PMT 2003]
A)
Leptotene done
clear
B)
Zygotene done
clear
C)
Pechytene done
clear
D)
Diplotene done
clear
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question_answer11)
Crossing-over occurs in the [Bihar MDAT 1995; MP PMT 1995; JIPMER 2002]
A)
Leptotene stage done
clear
B)
Pachytene stage done
clear
C)
Anaphase stage done
clear
D)
Diakinesis stage done
clear
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question_answer12)
Mendel observed that some characters did not assort independently. Later researchers found it to be due to [MP PMT 1995, 98]
A)
Crossing-over done
clear
B)
Linkage done
clear
C)
Dominance of one trait over the other done
clear
D)
Amitosis done
clear
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question_answer13)
Exchange of genetic material between chromatids of homologous chromosomes during meiosis is called [CBSE PMT 1996]
A)
Synapsis done
clear
B)
Chiasmata done
clear
C)
Transformation done
clear
D)
Crossing over done
clear
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question_answer14)
The scientists who have given the theory of linkage are [MP PMT 2001]
A)
Morgan and Castle done
clear
B)
Beadle and Tatum done
clear
C)
Watson and Crick done
clear
D)
Bateson and Punnet done
clear
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question_answer15)
In maize chromosome number is 2n = 20. The number of linkage groups in it shall be
A)
20 done
clear
B)
40 done
clear
C)
10 done
clear
D)
5 done
clear
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question_answer16)
The word 'crossing over' is given by
A)
Bateson done
clear
B)
Darlington done
clear
C)
Morgan done
clear
D)
Muller done
clear
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question_answer17)
Linkage decreases the frequency of [CPMT 1998]
A)
Hybrid done
clear
B)
Dominant allele done
clear
C)
Recessive allele done
clear
D)
Both (a) and (b) done
clear
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question_answer18)
Crossing over in diploid organism is responsible for [CBSE PMT 1998]
A)
Dominance of genes done
clear
B)
Linkage between genes done
clear
C)
Segregation of alleles done
clear
D)
Recombination of linked allele done
clear
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question_answer19)
Distance between two linked genes upon a chromosome is measured in cross over units, is [AIIMS 1998]
A)
Ratio of crossing over between them done
clear
B)
Cross-over value done
clear
C)
Number of other genes between them done
clear
D)
None of these done
clear
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question_answer20)
Linkage was first observed in [AFMC 2000]
A)
Field pea done
clear
B)
Sweet pea done
clear
C)
Pea done
clear
D)
Grass pea done
clear
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question_answer21)
What is the unit of crossing over
A)
Cistron done
clear
B)
Muton done
clear
C)
Recon done
clear
D)
None of the above done
clear
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question_answer22)
Crossing over that results in genetic recombination in higher organisms occurs between [CBSE PMT 2004, DPMT 2004, BVP 2004]
A)
Two daughter nuclei done
clear
B)
Two different bivalents done
clear
C)
Sister chromatids of a bivalent done
clear
D)
Non-sister chromatids of a bivalent done
clear
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question_answer23)
When closely placed genes on the same chromosome are inherited together the phenomenon is known as [Kerala PMT 2004]
A)
Qualitative inheritance done
clear
B)
Crossing over done
clear
C)
Gene interaction done
clear
D)
Multiple allelism done
clear
E)
Linkage done
clear
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question_answer24)
In order to calculate map distance of genes on a chromosome, one must know the
A)
Number of mutant genes done
clear
B)
Recombination frequency of each gene locus done
clear
C)
Cross over percentage done
clear
D)
Non-cross over percentage done
clear
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question_answer25)
Number of linkage group in Pisum sativum is [BVP 2004]
A)
2 done
clear
B)
5 done
clear
C)
7 done
clear
D)
9 done
clear
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question_answer26)
Sexual reproduction leads to [CPMT 2002]
A)
Genetic recombination done
clear
B)
Polyploidy done
clear
C)
Aneuploidy done
clear
D)
Euploidy done
clear
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question_answer27)
In the diplotene stage [DPMT 1993]
A)
Chromosomes are thin and long done
clear
B)
Homologous chromosomes undergo crossing over and chiasmata are seen done
clear
C)
Bivalents become very short and chaismata move towards ends of chromosomes done
clear
D)
Chromosomes have reached poles done
clear
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question_answer28)
For the preparation of genetic maps, the recombination frequencies between genes are additive over short distances but not over long distances due to [BHU 1994]
A)
Multiple cross overs done
clear
B)
Lethal mutation done
clear
C)
Epistasis done
clear
D)
Synaptonemal complex done
clear
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question_answer29)
Genetic recombination occur through [CPMT 2002]
A)
Mitosis and fertilization done
clear
B)
Mitosis and meiosis done
clear
C)
Meiosis and fertilization done
clear
D)
None of the above done
clear
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question_answer30)
When synapsis is complete all along the chromosome, the cell is said to have entered a stage called [AIIMS 2005]
A)
Zygotene done
clear
B)
Pachytene done
clear
C)
Diplotene done
clear
D)
Diakinesis done
clear
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question_answer31)
What will be the number of linkage groups in maize if it has 10 pairs of chromosomes [MP PMT 1999; DPMT 1980]
A)
5 done
clear
B)
10 done
clear
C)
Zero done
clear
D)
20 done
clear
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question_answer32)
Linked gene are separated by [CPMT 1994]
A)
Crossing over done
clear
B)
Mutation done
clear
C)
(a) and (b) both done
clear
D)
None of these done
clear
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question_answer33)
Chiasma shows the sites of [MHCET 2003]
A)
Spindle formation done
clear
B)
Synapsis done
clear
C)
Crossing over done
clear
D)
None of these done
clear
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question_answer34)
The four daughter cells derived from a single meiosis differ from each other due to [BHU 1994]
A)
Difference in chromosome number done
clear
B)
Crossing over only done
clear
C)
Independent assortment of chromosomes only done
clear
D)
Crossing over as well as independent assortment of chromosomes done
clear
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question_answer35)
Crossing over causes [CBSE PMT 1991]
A)
Expression of recessive genes done
clear
B)
Synapsis between homologous chromosomes done
clear
C)
Recombination between linked genes done
clear
D)
Linkage between dominant genes done
clear
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