Biology - Mock Test 124

Question 1231

E. Coli about to replicate was placed in a medium containing radio active thymidine for five minutes. Then it was made to replicate in a normal medium. Which of the following observation shall be correct?

A) Both the strands of DNA will be radio active B) One strand radio active C) Each strand half radio active D) None is radio active

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Question 1232

Ribosomal RNA is actively synthesized in?

A) Nucleoplasm B) Ribosomes C) Lysosomes D) Nucleolus

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Question 1233

What is true about ribosomes?

A) These are found only in eukaryotic cells B) These are self-splicing introns of some RNAs. C) The prokaryotic ribosomes are 80S, where "S" stands for sedimentation coefficient D) These are composed of ribonucleic acid and proteins

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Question 1234

Select the correct statement from the following regarding cell membrane ?

A) Lipids are arranged in a bilayer with polar heads towards the inner part. B) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson. C) Na+ and K+ ions move across cell membrane by passive transport. D) Proteins make up 60 to 70% of the cell membrane

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Question 1235

Which one of the following does not differ in E.coli and Chlamydomonas?

A) Cell wall B) Cell membrane C) Ribosomes D) Chromosomal organization

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Question 1236

Comparing small and large cells, which statement is correct?

A) Small cells have a small surface area per volume ratio B) Exchange rate of nutrients is fast with large cells C) Small cells have a large surface area per volume ratio D) Exchange rate of nutrients is slow with small cells

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Question 1237

The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?

A) Through elimination of repetitive DNA B) Deletion of non-essential genes C) Super-coiling in nucleosomes D) DNAse digestion

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Question 1238

Keeping in view the ‘fluid mosaic model’ for the structure of cell membrane, which one of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip-flop movement)?

A) Neither lipids, nor proteins can flip-flop B) Both lipids and proteins can flip-flop C) While lipids can rarely flip-flop, proteins can not D) While proteins can flip-flop, lipids can not

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Question 1239

Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it?

A) Adenine, Thymine – Purines B) Thymine, Uracil – Pyrimidines C) Uracil, Cytosine – Pyrimidines D) Guanine, Adenine – Purines

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Question 1240

Plasmodesmata are ?

A) Connections between adjacent cells B) Lignified cemented layers between cells C) Locomotary structures D) Membranes connecting the nucleus with plasmalemma

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