Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesised from it (DNA or RNA), list the types of nucleic acid polymerases.
Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesised from it (DNA or RNA), list the types of nucleic acid polymerases.
Solution and Explanation
There are two different types of nucleic acid polymerases.
(1) DNA-dependent DNA polymerases
(2) DNA-dependent RNApolymerases
The DNA-dependent RNA polymerases use a DNA template for synthesizing a new strand of DNA whereas DNA-dependent RNA polymerases use a DNA template strand for synthesizing RNA.
Top Questions on Molecular Basis of Inheritance
- The RNA triplet UAG acts as a stop codon which terminates the synthesis of a polypeptide. Below is given a strand of DNA which codes for four amino acids.
In which position will an insertion of a thymine nucleotide result in the termination of translation?
DNA strand:
3′ T C C A C C C G A T G C 5′- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
Construct and label a transcription unit from which the RNA segment given below has been transcribed. Write the complete name of the enzyme that transcribed this RNA.
- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
- The base sequence in one of the strands of DNA is: ‘TAGCATGAT’
- Give the base sequence of its complementary strand.
- How are these base pairs held together in DNA molecule?
- Explain the base complementarity rule. Name the scientist who framed this rule.
- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
Student to attempt either option-(A) or (B):
(A) Write the features a molecule should have to act as a genetic material. In the light of the above features, evaluate and justify the suitability of the molecule that is preferred as an ideal genetic material.
OR
(B) Differentiate between the following:- [(i)] Polygenic Inheritance and Pleiotropy
- [(ii)] Dominance, Codominance and Incomplete dominance
- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
- A segment of DNA, ‘TTG AGG GGG ATG’ was translated into an oligopeptide with the amino acids, Lysine - Serine - Proline - Tyrosine.
- [(a)] Write the codons in correct sequence for the four amino acids.
- [(b)] If first adenine in DNA is substituted by guanine, what will be the sequence of amino acids in the new oligopeptide?
- [(c)] Write the anticodons for these amino acids.
- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
Questions Asked in CBSE CLASS XII exam
Read the given passage carefully and answer the questions that follow :
In agriculturally important countries, agro products are exchanged for manufactured goods, whereas industrialised nations export machinery and finished products and import food grains and other raw materials. Foreign investment can boost trade in developing countries which lack in capital required for the development of mining, oil drilling, heavy engineering, lumbering and plantation agriculture. By developing such capital intensive industries in developing countries, the industrial nations ensure import of food stuffs, minerals and create markets for their finished products. This entire cycle steps up the volume of trade between nations.
- CBSE CLASS XII - 2025
- International Trade
Study the following graph carefully and answer the following questions
- CBSE CLASS XII - 2025
- Population Geography
Study the map of the Rhine waterway and answer the questions that follow :
- CBSE CLASS XII - 2025
- Transport and Communication
Study the following table carefully and answer the questions that follow :
India – Trends of Urbanisation
Year Number of Towns/UAs Urban Population (in Thousands) % of Total Population Decennial Growth (%) 1931 2,072 33,456.0 11.99 19.12 1941 2,250 44,153.3 13.86 31.97 1951 2,843 62,443.7 17.29 41.42 1961 2,365 78,936.6 17.97 26.41 1971 2,590 1,09,114 19.91 38.23 1981 3,378 1,59,463 23.34 46.14 1991 4,689 2,17,611 25.71 36.47 2001 5,161 2,85,355 27.78 31.13 - CBSE CLASS XII - 2025
- Population Geography
- “In India, water resources are getting polluted with industrial effluents, domestic waste, and insecticides used in agriculture.” Evaluate the statement.
- CBSE CLASS XII - 2025
- Water Resources
Concepts Used:
DNA Replication
The process by which the genome’s DNA is copied in cells is called DNA Replication. It must first copy (or replicate) its entire genome before cell division so that each resulting daughter cell ends up with its own complete genome.
It is the natural cycle of creating two indistinguishable imitations of DNA from one unique DNA molecule. DNA replication happens to take all things together living creatures going about as the most core part for organic legacy. This is important for cell division during the development and fixation of harmed tissues, while it likewise guarantees that every one of the new cells gets its duplicate of the DNA. The phone has the unmistakable property of division, which makes replication of DNA fundamental.
The parental DNA stays together, and the recently shaped daughter strands are together in conservative replication. The semi-conservative strategy recommends that every one of the two parental DNA strands goes about as a format for new DNA to be integrated; after that each two-fold abandoned DNA incorporates one "old" strand (parental) and one "new" strand.