Tiêu đề 8.CELL THE UNIT OF LIFE.pdf ✅

14. According to widely accepted "fluid mosaic model" cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect? NCERT Page-132 / N-94 (a) Proteins in cell membranes can travel within the lipid bilayer. (b) Proteins can also undergo flip-flop movements in the lipid bilayer. (c) Proteins can remain confined within certain domains of the membrane. (d) Many proteins remain completely embedded within the lipid bilayer. 15. Diagram given below represent a filuid mosaic model of plasma membrane. Match the components marked as A, B, C,D and E in the diagram below from the list (i) to (vii). NCERT Page-132 / N-93 (i) Sugar (ii) Protein (iii) Lipid bilayer (v) Cytoplasm (iv) Integral protein (vii) External protein (vi) Cell wall (a) A - (i), B - (ii), C - (iii), D - (iv), E - (v) (b) A - (ii), B - (i), C - (iii), D - (iv), E - (v) (c) A - (i), B - (ii), C - (iii), D - (iv), E - (vi) (d) A - (i), B - (ii), C - (iii), D - (vii), E - (v) 16. Active transport across bio membrane involves NCERT Page-132 / N-94 (a) production of ATP (b) requirement of energy (c) production of toxin (d) release of energy 17. Integral proteins of cell membrane occur on/in NCERT Page-131 / N-93 (a) inner surfaces (c) phospholipid matrix (b) outer surfaces (d) inner and outer surfaces 18. The fluidity of membranes in a plant in cold weather may be maintained by (a) increasing the number of phospholipids with unsaturated hydrocarbon tails. (b) increasing the proportion of integral proteins. (c) increasing concentration of cholesterol in membrane. (d) increasing the number of phospholipids with saturated hydrocarbon tail. 19. In which method of transport, plasma membrane does not require carrier molecule? NCERT-132 / N-94 (a) Active transport (b) Facilitated diffusion (c) Simple diffusion (d) Na+ − K +pump
20. The lipid component of the membrane mainly consists of NCERT Page-132 / N-93 (a) polysaccharides (b) phosphoglyceride (c) monosaccharaides (d) both (a) and (c) 21. Which of the following statements are correct? NCERT Page-132, 133 / N-94 (a) Na+/K +pump is an example of active transport. (b) In plant cells lipid like steroidal hormones are synthesized in SER. (c) In plant cells, the vacuoles can occupy up to 10% of the volume of the cell. (d) Chlorophyll and leucoplast are responsible for trapping light energy essential for photosynthesis. 22. Membrane of the erythrocytes has approximately % of proteins and % lipids. NCERT Page-131/N-93 (a) 42,50 (c) 50,50 (b) 52,40 (d) 60,40 23. The best material for study of structure of cell membrane is NCERT Page-131/N-93 (a) RBC of human (b) RBC of frog (c) cheek cell of human (d) liver cell of rat 24. Which one of the following structures between two adjacent cells is an effective transport pathway? (a) Plasmodesmata NCERT Page-132 / N-94 (b) Plastoquinones (c) Endoplasmic reticulum (d) Plasmalemma 25. Which of the following will determine the shape of the cells and provides a strong structural support to prevent the bacterium from bursting or collapsing? NCERT Page-132 / N-94 (a) Plasmids (c) Mesosome (b) Cell wall (d) Cell membrane 26. Which one of the following is not considered as part of the endomembrane system? (a) Golgi complex NCERT Page-133/N-94, 95 (b) Peroxisome (c) Vacuole (d) Lysosome 27. Which of the following cell organelles were discovered after the introduction of electron microscope? (a) Mitochondria (c) Ribosomes (b) Endoplasmic reticulum (d) Both (b) and (c) 28. _____is the important site of formation of glycoproteins and golycolipids. (a) SER (c) Golgi apparatus