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
- Both the strands of DNA will be radio active
- One strand radio active
- Each strand half radio active
- None is radio active
The Correct Option is B
Solution and Explanation
When E. coli is exposed to radioactive thymidine for a short period (5 minutes in this case), only one strand of the DNA will become radioactive. This is because DNA replication is a semi-conservative process. So, the correct observation is (B): One strand radioactive
Top Questions on Molecular Basis of Inheritance
Study the given below single strand of deoxyribonucleic acid depicted in the form of a “stick” diagram with 5′ – 3′ end directionality, sugars as vertical lines and bases as single letter abbreviations and answer the questions that follow.
Name the covalent bonds depicted as (a) and (b) in the form of slanting lines in the diagram.
How many purines are present in the given “stick” diagram?
Draw the chemical structure of the given polynucleotide chain of DNA.- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow.
(a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain?
(b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix.
(c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?- CBSE CLASS XII - 2025
- Biology
- Molecular Basis of Inheritance
Use the given information to select the amino acid attached to the 3′ end of tRNA during the process of translation, if the coding strand of the structural gene being transcribed has the nucleotide sequence TAC.
- 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
- Distance between two consecutive base pairs of DNA is \rule{2cm}{0.1mm}
- CBSE Compartment XII - 2025
- Biology
- Molecular Basis of Inheritance
Questions Asked in NEET exam
- In some appropriate units, time (t) and position (x) relation of a moving particle is given by \(t = \alpha x^2 + \beta x\). The acceleration of the particle is :
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The output (Y) of the given logic implementation is similar to the output of an/a …………. gate.
- NEET (UG) - 2025
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- Two identical point masses P and Q, suspended from two separate massless springs of spring constants \(k_1\) and \(k_2\), respectively, oscillate vertically. If their maximum velocities are the same, the ratio of the amplitude of P to the amplitude of Q is :
- NEET (UG) - 2025
- Waves and Oscillations
- A particle of mass \(m\) is moving around the origin with a constant speed \(v\) along a circular path of radius \(R\). When the particle is at \( (0, R) \), its velocity is \( \mathbf{v} = -v \hat{\mathbf{i}} \). The angular momentum of the particle with respect to the origin is :
- NEET (UG) - 2025
- The Angular Momentum
- The radius of Martian orbit around the Sun is about 1.5 times the radius of the orbit of Mercury. The Martian year is 687 Earth days. Then which of the following is the length of 1 year on Mercury?
- NEET (UG) - 2025
- Kepler’s laws
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.