Daily Static MCQs for UPSC & State PSC Exams - Science and Technology (30 June 2023)

Daily Static MCQs Quiz for UPSC, IAS, UPPSC/UPPCS, MPPSC. BPSC, RPSC & All State PSC Exams

Subject : Science and Technology

1. Consider the following statements regarding Distributed ledger technology (DLT):

1. Distributed ledger technology (DLT) is a digital system for recording the transaction of assets in which the details are recorded in multiple places at the same time.
2. Unlike traditional databases, distributed ledgers have a central data store or administration functionality.
3. Blockchain technology is a specific kind of Distributed ledger technology.

How many of the above statements is/are correct?

(a) Only one
(b) Only two
(c) All three
(d) None

Answer: (B)

Explanation:

  • Distributed ledger technology (DLT) is a digital system for recording the transaction of assets in which the transactions and their details are recorded in multiple places at the same time. Hence, statement 1 is correct.
    Unlike traditional databases, distributed ledgers have no central data store or administration functionality. Hence, statement 2 is incorrect.
  • Blockchain technology is a specific kind of DLT that came to prominence after Bitcoin, a cryptocurrency that used it, became popular. Cryptocurrencies such as Bitcoin use codes to encrypt transactions and stack them up in blocks, creating Blockchains. It is the use of codes that differentiates cryptocurrencies from other virtual currencies. Hence, statement 3 is correct.

2. Consider the following statements regarding Bio-enzymes:

1. Bio-enzymes are organic solutions produced through fermentation of organic waste like fruits, vegetable peels and flowers by mixing in sugar, jaggery/molasses and water.
2. Yeast can be used to slow down the process of fermentation.

Which of the above statements is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer: (A)

Explanation: Bio-enzymes are organic solutions produced through fermentation of organic waste including various fruits, vegetable peels and flowers, by mixing in sugar, jaggery/molasses and water. It takes 60-100 days to ferment organic waste. To fasten the fermentation, yeast can be used as culture to prepare it in 45-50 days. Hence, statement 2 is incorrect.

3. Which of the following are the applications of CRISPR technology?

1. Genetic sequences of disease-causing organisms can be altered to make them ineffective.
2. Diseases and disorders including some forms of cancer caused by an undesired genetic mutation can be fixed.
3. Genes of plants can be edited to make them withstand pests.

Select the correct answer using the code given below:

(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

Answer: (D)

Explanation: The CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology works in a simple way — it locates the specific area in the genetic sequence which has been diagnosed to be the cause of the problem, cuts it out, and replaces it with a new and correct sequence that no longer causes the problem. The technology replicates a natural defense mechanism in some bacteria that uses a similar method to protect itself from virus attacks. Because the entire process is programmable, it has a remarkable efficiency, and has already brought almost miraculous results. There are a whole lot of diseases and disorders, including some forms of cancer that are caused by an undesired genetic mutation. These can all be fixed with this technology. There are vast applications elsewhere as well. Genetic sequences of disease-causing organisms can be altered to make them ineffective. Genes of plants can be edited to make them withstand pests, or improve their tolerance to drought or temperature. Hence, all statements are correct.

4. Why are Bacteriophages seen as a possible therapy against multi-drug-resistant strains of many bacteria?

1. These are ubiquitous viruses found wherever bacteria exist and can kill bacteria.
2. They do not contain any RNA or DNA and thus cannot be infected by bacteria.

Which of the above statements is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer: (A)

Explanation: A bacteriophage is a type of virus that infects bacteria. In fact, the word “bacteriophage” literally means “bacteria eater,” because bacteriophages destroy their host cells. All bacteriophages are composed of a nucleic acid molecule that is surrounded by a protein structure. In other words, they are comprised of a protein capsule around an RNA or DNA genome. Hence, statement 2 is incorrect.

5. Normal cells show a property called “contact inhibition”. This property is helpful in regulating:

(a) Uncontrolled growth of cells
(b) Storage of fat component for emergency situations
(c) Amount of energy entering and leaving the cells
(d) All of the above

Answer: (A)

Explanation: In our body, cell growth and differentiation is highly controlled and regulated. Normal cells show a property called contact inhibition by virtue of which contact with other cells inhibits their uncontrolled growth. Contact inhibition is a process of arresting cell growth when cells come in contact with each other. Contact inhibition is a powerful anticancer mechanism. Hence, option (a) is correct.