11 NCERT BIOLOGY MOST IMPORTANT QUESTIONS

Q1. ATPase enzyme needed for muscle contraction is located in   1) Troponin   2) Actinin   3) Actin   4) Myosin   Solution During muscle contraction, hydrolysis of ATP into ADP and inorganic phosphate occurs. The energy released during the process raises the meromyosin head to a high-energy state. The enzyme myosin ATPase catalyses the reaction in the presence of Ca 2+ and Mg 2+ .       Q2. Draw a well-labelled diagram of the rib and rib cage.   Solution Rib and rib cage:         Q3. The membranous areas between the cranial bones of the foetal skull are called   1) Foramina   2) Fontanelle   ...

Q1. Sickle cell anaemia is due to 1) Change of amino acid in the β-chain of haemoglobin 2) Change of amino acid in the α-chain of haemoglobin 3) Change of amino acid in either α or β-chain of haemoglobin 4) Change of amino acid in both α and β chains of haemoglobin Solution The sixth amino acid from the amino terminal end of the β-chain of normal haemoglobin is glutamic acid, while it is valine in sickle cell haemoglobin. This replacement results in a change in confirmation of the haemoglobin molecule and RBC becomes sickle-shaped.  Q2. For the blood to flow from the right ventricle to the left ventricle in the mammalian heart, it must flow through   1) Right ventricle, Pulmonary veins, Lungs, Pulmonary arteries, Left atrium   ...

Q1. Which of the following is the cofactor of carbonic anhydrase?    1) Fe   2) Cu   3) Zn   4) Mg   Solution Carbonic anhydrase is a zinc-activated enzyme, so its cofactor is zinc.   Q2. Haemoglobin is a 1) Fat 2) Reproductive pigment 3) Carbohydrate 4) Respiratory pigment Solution Haemoglobin is a respiratory pigment which binds with oxygen to form oxyhaemoglobin and is then transported to various body cells for respiration. Q3. The vital capacity of the lungs includes    1) IRV + TV + ERV   ...