Karnataka 2nd PUC Biology Chapter 5 Important Questions 2027: Molecular Basis of Inheritance

The Karnataka 2nd PUC Biology Chapter 5 Important Questions 2027 are useful for students preparing the Biology board examination. Chapter 5, Molecular Basis of Inheritance, covers important concepts related to genetic material and the molecular processes involved in inheritance. 

Practising 2nd PUC Biology Chapter 5 Important Questions can help students revise important concepts, improve answer-writing skills, and identify topics that require additional attention. 

2nd PUC Biology Chapter 5 Important Questions 2027

Molecular Basis of Inheritance is Chapter 5 of Karnataka 2nd PUC Biology. Students should study the chapter thoroughly and focus on understanding the concepts before attempting important questions.

Some important areas to revise while preparing this chapter include:

• Molecular basis of inheritance

• Genetic material and its characteristics

• DNA and its organisation

• Molecular processes involved in inheritance

• Important biological terms and concepts related to the chapter

• Diagrams and processes that require step-by-step explanation

Students should refer to their prescribed textbook while preparing answers and ensure that important biological terms are used accurately.

2nd PUC Biology Chapter 5 1 Mark Questions

1. What is a nucleosome?

Answer: A nucleosome is the basic structural unit of chromatin in which DNA is wrapped around a core of histone proteins.

2. What is the role of DNA polymerase?

Answer: DNA polymerase catalyses the synthesis of a new DNA strand by adding nucleotides to the growing strand.

3. What is a codon?

Answer: A codon is a sequence of three nucleotides on mRNA that specifies an amino acid or a stop signal during protein synthesis.

2nd PUC Biology Chapter 5 2 Mark Questions

1. What are the functions of mRNA and tRNA?

Answer:

• mRNA: Carries genetic information from DNA to the ribosome for protein synthesis.

• tRNA: Carries specific amino acids to the ribosome and recognises the corresponding codons on mRNA.

2. What is semiconservative replication?

Answer: Semiconservative replication is the process in which each newly formed DNA molecule contains one parental strand and one newly synthesised strand. This mode of replication was demonstrated by Meselson and Stahl.

2nd PUC Biology Chapter 5 3 Mark Questions

1. Explain the complementary base pairing in DNA.

Answer:

1. DNA has two polynucleotide strands that are held together by hydrogen bonds between nitrogenous bases.

2. Adenine (A) pairs with Thymine (T) through two hydrogen bonds.

3. Guanine (G) pairs with Cytosine (C) through three hydrogen bonds.

2. Explain the three important steps of transcription.

Answer:

1. Initiation: RNA polymerase binds to the promoter region of DNA and initiates RNA synthesis.

2. Elongation: RNA polymerase uses one DNA strand as a template and adds complementary ribonucleotides.

3. Termination: The RNA polymerase reaches the termination region, and the newly formed RNA is released.

3. What are the salient features of the genetic code?

Answer:

1. The genetic code is triplet, meaning three nucleotides form one codon.

2. It is degenerate, as more than one codon can specify the same amino acid.

3. AUG acts as the initiation codon and also codes for methionine.

2nd PUC Biology Chapter 5 5 Mark Questions

1. Explain the structure of DNA according to the Watson and Crick model.

Answer:

1. DNA consists of two polynucleotide chains arranged in a double helix.

2. The two strands are antiparallel, with one strand running 5′→3′ and the other 3′→5′.

3. Each nucleotide consists of a deoxyribose sugar, phosphate group and nitrogenous base.

4. The nitrogenous bases of the two strands show complementary base pairing. Adenine pairs with thymine through two hydrogen bonds, while guanine pairs with cytosine through three hydrogen bonds.

5. The two strands are held together by hydrogen bonds, while nucleotides within each strand are joined by phosphodiester bonds.

2. Explain DNA replication.

Answer:

1. DNA replication begins with the unwinding and separation of the two DNA strands.

2. Each parental strand acts as a template for the synthesis of a new complementary strand.

3. DNA polymerase adds complementary nucleotides to the newly forming DNA strand.

4. The nucleotides are joined through phosphodiester bonds to form the sugar-phosphate backbone.

5. Two daughter DNA molecules are produced, each containing one parental strand and one newly synthesised strand. Hence, DNA replication is called semiconservative replication.

3. Explain the process of translation.

Answer:

1. Initiation: The ribosome binds to mRNA, and the initiator tRNA recognises the start codon, AUG.

2. Elongation: tRNAs bring specific amino acids according to the codon sequence on mRNA. Peptide bonds are formed between adjacent amino acids.

3. The ribosome moves along the mRNA, allowing successive amino acids to be added to the growing polypeptide chain.

4. Termination: When a stop codon is reached, translation stops and the completed polypeptide is released.

5. Thus, translation converts the genetic information present in mRNA into a specific sequence of amino acids.

How to Prepare for Karnataka 2nd PUC Biology Chapter 5?

Students should focus on understanding Molecular Basis of Inheritance, revising key terms, practising questions, and improving accuracy through regular revision and self-assessment.

• Read the chapter carefully and understand its key concepts.

• Prepare concise notes on definitions, processes, and important terms.

• Practise PYQs regularly to strengthen understanding.

• Revise diagrams, model papers and important biological processes.

• Analyse mistakes and improve accuracy after each practice session.

PW provides Karnataka 2nd PUC exam content, including Karnataka Board Exam Blogs, sample papers, mock tests, guidance sessions, and more. Also, enroll today in Karnataka 2nd PUC Online Coaching to prepare. 

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