If a chiasma forms between the loci of genes A and B in 20% of the tetrads of an individual of genotype AB/ab, the percentage of gametes expected to be Ab is:

1. 40

2. 20

3. 10

4. 5

Subtopic:  Linkage |
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NEET 2023 - Target Batch - Aryan Raj Singh
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Phenotype of an organism is the result of:

1. mutations and linkages

2. cytoplasmic effects and nutrition

3. environmental changes and sexual dimorpgism

4. genotype and environment interactions

Subtopic:  Introduction to Genetics: 1 | Introduction to Genetics: 2 |
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AIPMT - 2006
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Both sickle cell anaemia and Huntington’s chorea are:

1. bacteria-related diseases.

2. congenital disorders

3. pollutant-induced disorders

4. virus-related diseases

Subtopic:  Mendelian Disorders: Sickle Cell Anemia | Mendelian Disorders |
 80%
AIPMT - 2006
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The dominant epistasis ratio is:

1. 9:3:3:1

2. 12:3:1

3. 9:3:4

4. 9:6:1

Subtopic:  Epistasis |
 56%
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Select the correct statement from the options given below with respect to the dihybrid cross.

1. Tightly linked genes on the same chromosome show higher recombination

2. Genes for apart on the same chromosomes show very few recombination

3. Genes that are loosely linked on the same chromosomes. Show similar recombination as lightly linked ones

4. Tightly linked genes on the same chromosomes show very few recombination

Subtopic:  Linkage Types | Recombination & Gene Mapping |
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Two genes R and y are located very close on the chromosome linkage map on maize plant. When RRYY and rryy genotypes are hybridized, then F2 segregation will show:

1. Higher number of the recombinant types

2. Segregation with expected 9:3:3:1 ratio

3. Segregation is 3:1 ratio

4. Higher number of parental types

Subtopic:  Linkage Types | Recombination & Gene Mapping |
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A woman with two genes (one on each X-chromosome) for haemophilia and one gene for colour blindness on the X-chromosome marries a normal man. How will the progeny be?
 

1. All sons and daughters are haemophilic and colour blind
2. Haemophilic and colour blind daughters
3. 50% haemophilic colour blind sons and 50% haemophilic sons
4. 50% haemophilic daughters and 50% colour blind daughters
Subtopic:  Mendelian Disorders |
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A hereditary disease which is never passed on from father to son is:

1. X-chromosomal linked disease

2. Autosomal linked disease

3. Y-chromosomal linked disease

4. None of the above

Subtopic:  Mendelian Disorders |
 66%
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A polygenic inheritance in human beings is:

1. skin colour

2. sickle cell anaemia

3. colour blindness

4. phenylketonuria

Subtopic:  Polygenic Inheritance & Pleiotropy |
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The year 1900 AD is highly significant for geneticists due to:

1. discovery of genes

2. Principle of linkage

3. Chromosome theory of heredity

4. Rediscovery of Mendelism

Subtopic:  Chromosomal Basis of Inheritance: Further Considerations |
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