Karnataka 1st PUC Biology Chapter 12 Respiration in Plants Important Questions

Respiration in Plants is an important chapter in Karnataka 1st PUC Biology. It introduces students to the process through which plants break down food to release energy for various life activities.

Understanding the different stages of respiration is essential for learning how energy is produced in plant cells. Karnataka 1st PUC Biology Chapter 12 Important Questions cover major topics such as glycolysis, fermentation, the Krebs cycle, and the electron transport system. 

Practising these questions can help students revise key concepts, understand important processes, and prepare clear answers for the 2026–27 examination. Before starting revision, refer to the Karnataka Class 11 Biology syllabus to review the prescribed topics. The questions below cover important concepts from Respiration in Plants.

Important Questions on Karnataka 1st PUC Biology Chapter 12 Respiration in Plants

Practise the following questions to revise the key concepts of Chapter 12.

1. Select the wrong statement with respect to glycolysis.

(A) It occurs outside mitochondria.
(B) It is an anaerobic phase.
(C) Glucose undergoes partial oxidation to form two molecules of pyruvic acid.
(D) Glucose is phosphorylated to glucose-6-phosphate by the isomerase enzyme.

2. Which of the following steps during glycolysis is associated with the utilisation of ATP?

(A) Glucose → Glucose-6-phosphate
(B) Fructose-6-phosphate → Fructose-1,6-bisphosphate
(C) PEP → Pyruvic acid
(D) Both (A) and (B)

3. Which of the following conversions involve ATP synthesis during glycolysis?

(A) Glucose → Glucose-6-phosphate
(B) Fructose-6-phosphate → Fructose-1, 6-biphosphate
(C) 1, 3-bisphosphoglyceric acid (BPGA) → 3-phosphoglyceric acid (PGA))
(D) All of these

4. Fate of pyruvic acid during aerobic respiration is

(A) Lactic acid fermentation
(B) Alcoholic acid fermentation
(C) Oxidative decarboxylation
(D) Oxidative phosphorylation

These Respiration in Plants 1st PUC Biology Important Questions cover major concepts from the chapter. While preparing, understand the sequence of respiratory processes, revise the differences between aerobic and anaerobic respiration, and practise diagrams of the major metabolic pathways.

Karnataka 1st PUC Biology Chapter 12 Important Questions PDF

Students can refer to the official 2026–27 Biology chapter Respiration in Plants during revision. The chapter PDF can help students review the prescribed content and understand the topics covered.

You can also practise with the Karnataka 1st PUC Biology model question paper to become familiar with the question format.

How to Prepare for Karnataka 1st PUC Biology Chapter 12

To prepare effectively for Respiration in Plants, focus on understanding the stages of respiration and revising important definitions, differences, and diagrams. Follow these steps during your preparation:

• Understand the overall process of respiration and its importance in plants.

• Revise glycolysis, fermentation, the Krebs cycle, and the electron transport system.

• Practise drawing and explaining the major stages of cellular respiration.

• Understand the respiratory quotient and its significance for different respiratory substrates.

• Refer to the Karnataka PUC 1 syllabus to review syllabus-related information.

• Solve the Karnataka 1st PUC mid-term question papers with answer keys for additional practice.

• Check the Karnataka 1st PUC exam pattern to understand the examination structure.

Practising Karnataka 1st PUC Biology Chapter 12 Important Questions helps students understand glycolysis, fermentation, the Krebs cycle, and aerobic respiration. 

Revise important reactions, enzymes, and energy-producing steps to strengthen your concepts. Practise MCQs and descriptive questions regularly, refer to the official chapter PDF, and solve model question papers for effective preparation for the 2026–27 examination.