NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement
The NCERT Exemplar Solutions for Class 11 Biology Chapter 20, Locomotion and Movement, focus on how organisms move and the systems that enable locomotion in humans. This chapter introduces the types of movements, muscle contraction, skeletal structure, joints, and locomotor disorders. The NCERT Exemplar problems are designed to strengthen conceptual understanding, improve problem-solving ability, and prepare students for both board exams and competitive exams like NEET.
The chapter begins with types of movement in living organisms. These include amoeboid movement (as in macrophages), ciliary movement (as in respiratory tract cells), and muscular movement, which is the most common in higher animals. Exemplar questions often test the ability to differentiate among these types with examples. The focus then shifts to muscles and their types—skeletal, smooth, and cardiac muscles. Skeletal muscles are voluntary and help in locomotion, smooth muscles are involuntary and found in visceral organs, while cardiac muscles are specialized for continuous rhythmic contraction. Exemplar questions frequently involve comparing their structure and functions. A major highlight of the chapter is the mechanism of muscle contraction. It is explained using the sliding filament theory, where actin and myosin filaments slide past each other to shorten the muscle. The role of calcium ions and ATP in contraction is also emphasized. Exemplar questions may ask students to analyze diagrams of sarcomeres, explain cross-bridge formation, or identify the significance of calcium in contraction.
The chapter also explains the skeletal system, which provides structural support, protection, and aids in movement. The human skeleton is divided into the axial skeleton (skull, vertebral column, ribs, sternum) and appendicular skeleton (limbs and girdles). Exemplar problems often include labeling exercises or reasoning-based questions about skeletal functions. Joints are another important topic, classified into fibrous, cartilaginous, and synovial joints. Synovial joints such as hinge, ball-and-socket, pivot, and gliding joints are studied in detail. Exemplar questions usually test the application of these concepts, like identifying the joint involved in specific body movements. The chapter also addresses disorders related to locomotion, such as arthritis, osteoporosis, and muscular dystrophy. Exemplar questions may ask students to explain causes, symptoms, and preventive measures, helping them connect theoretical knowledge with real-life health issues. For exam preparation, students are encouraged to review diagrams of the human skeleton, muscles, and joints carefully. Exemplar questions from this chapter often involve both diagram-based and application-oriented problem-solving, ensuring that learners build both conceptual and analytical skills. In conclusion, NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement provide a thorough understanding of the muscular and skeletal systems that support human movement. By solving Exemplar questions, students can enhance clarity, develop reasoning skills, and prepare confidently for board exams and medical entrance tests.