IGNOU LSE-01 - Cell Biology

1. State one important function of each of the following: i) F1 particles ii) cytochrome b iii) Plasmodesmata iv) Myelin sheath v) Thrombocytes 2. Differentiate between the following pairs: i) Ion exchange and Affinity chromatography ii) m-RNA and t-RNA iii) Microtubules and Microfilaments iv) Phagocytosis and Pinocytosis 3. Write short notes on any of the following: i) Autoradiography ii) Structure of plasma membrane iii) Meiosis I iv) cAMP as second messenger in cell 4. Draw neat and well labelled diagrams of the following: i) A motor neuron ii) Watson and Crick model of DNA 5. Name the major macromolecules present in the cell. Describe any two methods of separating macromolecules on the basis of differences in their molecular weight. 6. a) Describe the components of fluid connective tissue in animals. b) What is meristem? Discuss its role in plants. 7. a) Explain enzyme kinetics b) Discuss the genetic control of enzyme activity with the help of operon model. 8. a) Describe the structure and function of nuclear envelope b) How is polypeptide chain synthesis initiated in prokaryotes? 9. Describe the formation of proton gradient caused by electron transfer in mitochondira, chloroplasts and bacteria. 10. Describe how glycolysis and TCA cycle are linked to each other.

1. Write short notes on the following: (i) Autoradiography (ii) Gluconeogenesis (iii) Cytokinesis (iv) Phagocytosis  2. (a) Describe the structure of Golgi apparatus with the help of a well labelled diagram. List some of its important functions. (b) Explain how protein synthesis in prokaryotes different from that in eukaryotes.  3. Differentiate between following pair of terms: (i) Endocytosis and Exocytosis (ii) Microtubules and microfilaments (iii) DNA and RNA iv) Cilia and Flagella   4. (a) Describe the technique of column chromatography. (b) Explain the structure of nerve cell with the help of a well labelled diagram.  5. Explain in detail the tricarboxylic acid (TCA) cycle with the help of a well labelled diagram.  6. (a) Describe various phases of cell cycle. (b) Protein synthesis is regulated at various levels. Justify the statement giving a suitable explanation. 7. (a) Describe the molecular organization of cell membrane. (b) Explain in brief the chemiosmotic theory.  8. (a) Describe the structure and function of tRNA. (b) Describe double helix model of DNA.  9. Explain various stages of mitotic division with the help of suitable diagrams. 10. (a) What are allosteric enzymes? Describe their mechanism of action. (b) Describe bacterial chemotaxis.