Tag: biology

Questions Related to biology

Wild type Escherichia coli growing on medium having glucose is transferred to lactose containing medium. Which change occurs?

expression of gene inherited changes biology

  1. Lac operon is induced

  2. Lac operon is suppressed

  3. All operons are induced

  4. The bacterium stops dividing

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Correct Option: A

In repressible or negative operon

expression of gene inherited changes biology

  1. Corepressor binds with inducer

  2. Corepressor binds with aporepressor

  3. Corepressor does not bind with repressor

  4. cAMP has negative effect

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Correct Option: B

In lac-operon, repressor protein binds to

expression of gene inherited changes biology

  1. Regulator gene

  2. Operator gene

  3. Promoter gene

  4. Structural gene

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Correct Option: B

Operon contains

expression of gene inherited changes biology

  1. Operator and regulator genes

  2. Operator and structural genes

  3. Operator and regulator genes, and repressor

  4. Operator gene, regulator gene, repressor, structural genes and promoter gene

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Correct Option: D

Telomere of eucaryotic chromosome possesses short segments of

expression of gene inherited changes biology

  1. Guanine rich repeats

  2. Thymine rich repeats

  3. Cytosine rich repeats

  4. Adenine rich repeats

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Correct Option: A

Lac operon is

expression of gene inherited changes biology

  1. Arabinose operon

  2. Repressible operon

  3. Inducible operon

  4. Overlapping genes

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Correct Option: C

Eucaryotic genome differs from procaryotic genome in

expression of gene inherited changes biology

  1. DNA is circular arid single-stranded in procaryotes

  2. Intervening sequences are present in eucaryotic DNA

  3. DNA is coinplexed with histones in procaryotes

  4. DNA is organised into operons in eucaryotes

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Correct Option: B

Operon is

expression of gene inherited changes biology

  1. Sequence of three nitrogen bases determining a single amino acid

  2. A set of closely placed genes regulating a metabolic pathway in procaryotes

  3. Segment of DNA specifying a polypeptide

  4. Gene responsible for switching on and switching off of other genes

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Correct Option: B

In eukaryotes transcription occurs in

expression of gene inherited changes biology

  1. Cytoplasm

  2. Nucleus

  3. Cytosol

  4. Matrix

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Correct Option: B

In an inducible operon, the genes are

expression of gene inherited changes biology

  1. Usually expressed unless a signal turns them "off

  2. Never expressed

  3. Always expressed

  4. Usually not expressed unless a signal turns them on

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Correct Option: D