Molecular Basis of Inheritance · Question 87

Satellite DNA is important because it :

1. Shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children.
2. does not code for proteins and is same in all members of the population.
3. codes for enzymes needed for DNA replication.
4. codes for proteins needed in cell cycle.

Gene regulation governing lactose operon of E. coli that involves the lac I gene product is

1. negative and inducible because repressor protein prevents transcription.
2. positive and inducible because it can be induced by lactose
3. negative and repressible because repressor protein prevents transcription
4. feedback inhibition because excess of -galactosidase can switch off transcription

In sea urchin DNA, which is double stranded, 17% of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are

1. G 17%, A 16.5%, T 32.5%
2. G 17%, A 33%, T 33%
3. G 8.5%, A 50%, T 24.5%
4. G 34%, A 24.5%, T 24.5%

Which one of the following is wrongly matched?

1. Transcription – Writing information from DNA to t-RNA
2. Operon – Structural genes, operator and promoter
3. Repressor protein – Binds to operator to stop enzyme synthesis
4. Translation – Using information in m-RNA to make protein.

Transformation was discovered by :

1. Griffith
2. Watson and Crick
3. Hershey and Chase
4. Meselson and Stahl

Select the correct option ;

1. Direction of RNA synthesis 3'–5', Direction of reading of the template DNA strand 5'–3'
2. Direction of RNA synthesis 5'–3', Direction of reading of the template DNA strand 5'–3'
3. Direction of RNA synthesis 5'–3', Direction of reading of the template DNA strand 3'–5'
4. Direction of RNA synthesis 3'–5', Direction of reading of the template DNA strand 3'–5'

An analysis of chromosomal DNA using the Southern hybridization technique does not use:

1. Blotting
2. PCR
3. Electrophoresis
4. Autoradiography

Commonly used vectors for human genome sequencing are :

1. BAC and YAC
2. T/A Cloning Vectors
3. T-DNA
4. Expression Vectors

The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C. [figure]

1. A-translation B-extension C-Rosalind Franklin
2. A-translation B-transcription C-Erwin Chargaff
3. A-transcription B-translation C-Francis Crick
4. A-transcription B-replication C-James Watson

Which enzyme will be produced in a cell in which there is a non-sense mutation in the lac Y gene ?

1. Transacetylase
2. Lactose permease and transacetylase
3. Lactose permease
4. -galactosidase