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#Question id: 1900


Which of the following statements is TRUE of the human major histocompatibility complex (MHC)?

#Unit 4. Cell Communication and Cell Signaling
  1. MHC provokes the most intense allograft reactions

  2. MHC is termed H-2

  3. MHC contains only class I and class II genes

  4. MHC is not expressed as codominant antigens on the cell surface

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TLS Online TPP Program

#Question id: 4896

#Unit 8. Inheritance Biology

A cross between individuals with genotypes AaBbX aabb produces the following progeny:

AaBb -  21, aaBb- 83, Aabb-   77,  aa bb -19

Which of the following statements is true?

a) Map unit between gene A and B

b) Configuration

c) parents genotype of AaBb

TLS Online TPP Program

#Question id: 4897

#Unit 8. Inheritance Biology

When two independent pure lines AAbb and aaBB of pea with white flowers are crossed, the F1 progeny has purple flowers. Gene A and B link at 20 map unit. The following conclusions were made

A. When an heterozygous individual of the genotype AaBb is test crossed, progenies with purple and white in a ratio of 1:3

B. When an heterozygous individual of the genotype AaBb is test crossed, progenies with purple and white in a ratio of 1:9

C. This is an example of complementary gene action

D. The F2 progeny obtained on selfing shows both pruple and white flower in a ratio of 9:7                                            

Which of the following conclusions are correct?

TLS Online TPP Program

#Question id: 4898

#Unit 8. Inheritance Biology

A three point test cross was carried out in Drosophila melanogaster involving three adjacent genes A, B and C. arranged in the same order. The distance between A to B is 15 map unit (mu) and that between B to C is 30 map. The coefficient of coincidence = 0.67. What is the percentage of double recombinants in the progeny obtained from the testcross?

TLS Online TPP Program

#Question id: 4899

#Unit 8. Inheritance Biology

In Neurospora a cross between the genotypes 'A' and 'a' results in an ascus with ascospores of genotypes as shown below: 

Ascus Class

Ascospore

I

A

A

A

A

a

a

a

a

II

A

A

a

a

a

a

A

A

                   

 Statements A to D are events that could have occurred during meiosis.

A) Class I is results of no crossing over between the centromere and gene.

B) Class II is results of single crossing over between the centromere and gene

C) Class I shows segregation of alleles 'A' and 'a' in meiosis II

D) Class II shows segregation of alleles 'A' and 'a' in meiosis II

TLS Online TPP Program

#Question id: 4900

#Unit 8. Inheritance Biology

The chlorophyll-deficient types occur in a particular plant species due to a mutation in the DNA of the chloroplast itself, Female cytoplasm chlorophyll-deficient organisms crossed with male normal chlorophyll will produce progeny

TLS Online TPP Program

#Question id: 4900

#Unit 8. Inheritance Biology

The chlorophyll-deficient types occur in a particular plant species due to a mutation in the DNA of the chloroplast itself, Female cytoplasm chlorophyll-deficient organisms crossed with male normal chlorophyll will produce progeny