Download App

Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance1 Mark
MCQ
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
 Assertion: The concept of one gene$-$one enzyme was changed to one gene$-$one polypeptide.
Reason: Each enzyme may consist of two or more different polypeptides.
  • ✓
    Both assertion and reason are true, and reason is the correct explanation of assertion.
  • B
    Both assertion and reason are true, but reason is not the correct explanation of assertion.
  • C
    Assertion is true, but reason is false.
  • D
    Both assertion and reason are false.
✓

Answer

Correct option: A.
Both assertion and reason are true, and reason is the correct explanation of assertion.
In $1948,$ Beadle and Tatum proposed that a gene controls the synthesis of one enzyme. But, many enzymes, as well as the haemoglobins were shown to consist of two or more different polypeptide chains and each polypeptide was found to be the product of a separate gene. Tryptophan synthetase of $E$. coli, for example, contains an $\alpha$ polypeptide, the product of the trp $A$ gene and $\beta$ polypeptide, the product of the $\beta$ gene It was necessary, therefore, to change the concept of one gene$-$one enzyme to one gene$-$one polypeptide.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Molecular Basis of Inheritance→Molecular Basis of Inheritance — all question types→BIOLOGY STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Directions: In the following questions, the Assertions $(A)$ and Reason$(s) (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Recognition site should be preferably single and responsive to commonly used restriction enzyme.
Reason: In $\text{pBR} 322$ alien $\text{DNA}$ is ligated generally in the area of Bam $- \text{HI}$ site of tetracycline resistance gene.
→
The purpose of biopiracy is :
→
For two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: $\text{PCR, ELISA, DNA}$ hybridisation are confirmatory tests for sexually transmitted diseases.
Reason: Incidence of $\text{STDs}$ are very high in persons above the age of $30.$
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Dendritic cells originate in the bone marrow.
Reason: Dendritic cells are found in neuron.
→
Silencing of a gene could be achieved through the use of :
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Tranquillizers are used to treat schizophrenia.
Reason: Tranquillizers are antipsychosis drugs.
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Synthesis of tryptophan is self regulatory.
Reason: Tryptophan works both as co$-$repressor and through feedback inhibition.
→
For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $\text{(a), (b), (c)}$ and $(d)$ as given below.
Assertion: Complementary genes are non-allelic genes.
Reason: Complementary genes interact to produce a completely new trait.
→
Human insulin is being commercially produced from transgenic species of $...........$
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : $\text{SCID}$ is the first genetic disorder to be combated with gene therapy.
Reason : $\text{SCID}$ is a type of allergy.
→