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#Question id: 15287


Following are postulates of mechanism of differentiation. Which of the following is incorrect?

#Unit 5. Developmental Biology
  1. Every somatic cell nucleus of an organism contains the complete genome established in the fertilized egg, it means the DNAs of all differentiated cells are identical.
  2. The unused genes in differentiated cells are neither destroyed nor mutated; they retain the potential for being expressed.
  3. Only used genes have the potential for being expressed while unused genes  are either destroyed or mutated.
  4. Only a small percentage of the genome is expressed in each cell, and a portion of the RNA synthesized in each cell is specific for that cell type
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TLS Online TPP Program

#Question id: 5756

#Unit 8. Inheritance Biology

Type of mutation caused by an addition or deletion of a base in a polypeptide-encoding part of a gene

TLS Online TPP Program

#Question id: 5757

#Unit 8. Inheritance Biology

A new E. coli mutant was tested for auxotrophy. The mutant grows on:

minimal medium (M) + arginine (A) + proline (P)

M + P + histidine (H)

M + A + H + P

but not on M or on M + A + H. The mutant requires

TLS Online TPP Program

#Question id: 5758

#Unit 8. Inheritance Biology

Consider a species with a diploid (2n) number of 28 chromosomes. How many chromosomes would be found in a monoploid body cell?

TLS Online TPP Program

#Question id: 5760

#Unit 8. Inheritance Biology

The fluctuation test of Luria and Delbruck (studying resistance to bacteriophge T1 infection) established that

TLS Online TPP Program

#Question id: 5761

#Unit 8. Inheritance Biology

E. coli cells were spread on an agar plate, producing 1000 colonies.  The colonies are replica plated on two agar plates containing the antibiotic kanamycin and one agar plate without antibiotics.  All of the colonies are able to grow on the agar plate without antibiotic but only 4 colonies are able to grow on each of the agar plates containing kanamycin.  You notice that the four colonies that grew on each of the kanamycin containing plates are in the exact same position.  This demonstrates

TLS Online TPP Program

#Question id: 5762

#Unit 8. Inheritance Biology

An individual cell homozygous for a mutant allele of the gene for a human enzyme contains no detectable activity for that enzyme. The mutation is best described as