NEET CH-8 CELL: THE UNIT OF LIFE

NCERT QUESTION

TRUE OR FALSE (T or F)

1.The cytoplasm is the main arena of cellular activities in both the plant and animal cells.

2. In both prokaryotic and eukaryotic cells, a semi fluid matrix called cytoplasm and nucleus occupies the volume of the cell.

3. Anything less than a complete structure of a cell does not ensure independent living.

4. Schleiden, a German botanist examined a large number of plants and observed that all plants are composed of different kinds of cells which form the tissues of the plant.

5. The cells of human cheek has a distinct cell wall as its outer boundary and just within it is the cell membrane.

6. Schwann, a british zoologist concluded, based on his studies on plant tissues that the presence of cell wall is a unique character of the plant cells.

7. Glycocalyx provides sticky character to the bacterial cell.

8. The concept of ‘Omnis cellula-e-cellula’ regarding cell division was first proposed by Rudolf Virchow.

9. Plasmid DNA is genomic DNA as they are small and circular.

10. Various chemical reactions occur in the cells to keep it in the living state.

11. Within the prokaryotic cell, ribosomes are found not only in the cytoplasm but within some cell organelles.

12. Ribosomes are membrane bound organelles found in both eukaryotic as well as prokaryotic cells.

13. Mycoplasmas, the smallest cells are only 0.3 um in length.

14. A specialised differentiated form of cell membrane called mesosome is the characteristic of prokaryotes.

15. Endomembrane system includes cell organelles like endoplasmic reticulum, golgi complex, lysosomes and vacuoles because their functions are coordinated.

16. The cell wall of a young plant cell, the primary wall is capable of growth, which gradually diminishes as the cell matures and the secondary wall is formed on the inner side of the cell.

17. Cholesterol is not a constituent of cell membrane.

18. The cell wall and middle lamella may be traversed by plasmodesmata which connect the cytoplasm of neighbouring cells.

19. In human beings, the membrane of the erythrocyte has approximately 52 percent protein and 49 par cent lipids.

20. Pili and fimbriae donot help in motility of bacterial cells but help to attach to the rocks.

21. Inclusion bodies in prokaryotic cells are not bound by any membrane system and lie free in the cytoplasm.

22. Lipids are arranged in a bilayer with polar heads towards the inner side in the cell membrane.

23. Gas vacuoles are found in blue green and purple and green photosynthetic bacteria.

24. Plant cells are different from animal cells as they lack non membrane bound organelle called centrioles.

25. The plasma membrane consists mainly of phospholipids embedded in a protein bilayer.

26. Lysosome is involved in digesting biomolecules.

27. Golgi apparatus is important site of formation of glycoproteins and glycolipids in prokaryotic cells.

28. The concentration of icons is significantly higher in the vacuole than in the cytoplasm.

29. In some prokaryotes like cyanobacteria, ther are other membranous extensions into the cytoplasm called chromatophores which contain pigments.

30 Typically mitochondria is sausage shaped or cylindrical having a diameter of 0.2 to 1 um and length 1.0- 4.1 um.

31. Lysosomes are formed by the process of packaging in the endoplasmic reticulum.

32. The golgi complex is present in higest number in secretory cells.

33. Outer membrane of mitochondria forms the discontinuous boundary of the organelle.

34. Amyloplasts store carbohydrates, elaioplasts store oils and fats whereas the aleuroplasts store proteins.

35. Mitochondria are semi-autonomous organelles and they divide by fission.

36. In the chromoplast fat soluble carotenoid pigments like carotene, xanthophylls and others are present.

37. Nucleus is double membrane bound structure but nucleolus is single membrane bound.

38. The perinuclear space is a space in cytoplasm around the nucleus.

39. Non membranous nucleoplasmic structures in nucleus are the site for active synthesis of rRNA.

40. The shorter and longer arms are present only inmetacentric and acrocentric chromosomes.

41. Nuclear envelope is a derivative of SER.

42. Ribosomes are structures which can be seen within an organelle.

43. The ribosomes of the chloroplasts are smaller (70S) than the cytoplasmic ribosomes (80S).

44. Both cilia and flagella emerge from centriole like structure called basalbodies in prokaryotes.

45. The prokaryotic bacteria also possess flagella but these are structurally different from that of the eukaryotic flagella.

46. The centrioles form the basal body of cilia and flagella, and spindle fibres that give rise tospindle apparatus during cell division in animal cells.

47. Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as polysome.

48. An elaborate network of filamentous proteinaceous structures consisting of microtubules, microfilaments and intermediate filaments present in the cytoplasm is collectively referred to as the cytoskeleton.

49. The core of the ciliumand flagellum is called the axoneme which contains nine doublets of radially arranged peripheral microtubules.

50. Microtubules are the constituents of centrioles, spindle fibres and chromatin.

ANSWER

1.T, 2.F, 3.T, 4.T, 5.F, 6.T, 7.T, 8.T, 9.F, 10.T,

11.F, 12.F, 13.T, 14.T, 15.T, 16.T, 17.F, 18.T, 19.T, 20.F,

21.T, 22.F, 23.T, 24.T, 25.F, 26.T, 27.F, 28.T, 29.T, 30.T,

31.F, 32.T, 33.F, 34.T, 35.T, 36.T, 37.F, 38.F, 39.T, 40.F,

, 41.F, 42.T, 43.T, 44.F, 45.T, 46.T, 47.T, 48.T, 49.T, 50.F

QUOTE:- “SUCCESS IS NOT FINAL ; FAILURE IS NOT FATAL;
IT IS THE COURAGE TO CONTINUE THAT COUNTS”.