Cell and Molecular Biology – Short Questions with Answers

Cell and Molecular Biology Short Questions Eduhyme

Every cell, prokaryotic or eukaryotic, is surrounded by a thin layer of outermost boundary called the plasma membrane or cell membrane or plasma – lemma. The plasma membrane is a discrete structure and is remarkably complex in its molecular organization.

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This article provides a quick review of short questions and answers used in the study of Cell and Molecular Biology.

Q1. What are prokaryotes? Give an example.
Answer – Organisms without an organized nucleus e.g., Bacteria

Q2. What are eukaryotes? Give few examples.
Answer – Organisms with an organized nucleus. Plants, yeast;

Q3. Cell is an open dynamic system. Is it correct?
Answer – Yes

Q4. Prokaryotic cells are haploid. Is it so?
Answer – Yes

Q5. What are cyanobacteria?
Answer – Blue green algae

Q6. Give three essential characteristics of cell?
Answer – Cell membrane, cytoplasm, nuclear material

Q7. Where is nucleolus found?
Answer – Nucleus

Q8. What are the power houses of the cell?
Answer – Mitochondria

Q9. Name the protein factories of prokaryotic and eukaryotic cells?
Answer – Ribosome

Q10. What is the control centre of a cell?
Answer – Nucleus

Q11. What is the thickness of plasma membrane?
Answer – 70 – 100Å.

Q12. Who proposed the fluid mosaic hypothesis for the molecular structure of cell membrane?
Answer – Singer and Nicolson.

Q13. What is the structure of plasma membrane?
Answer – It is formed of bilayer of lipids into which protein complexes are embedded in a kind of mosaic arrangement.

Q14. What are the main lipid components of the plasma membrane?
Answer – Phospholipids, cholesterol and galactolipids.

Q15. What are the two types of proteins of the plasma membrane on the basis of their association with the membrane and their solubility?
Answer – Integral or intrinsic proteins and peripheral or extrinsic proteins.

Q16. What are tunnel proteins?
Answer – Large integral protein molecules that lie throughout the phospholipid matrix and projects on both the surfaces.

Q17. Why Na+ -K+ ATPase enzyme is most important?
Answer – It helps in ion transfer across the plasma membrane. This enzyme is dependent on the presence of lipids and is inactivated when all lipids are extracted.

Q18. Who proposed that plasma membrane contained a lipid bilayer and protein adhering to both lipid aqueous interfaces?
Answer – Danielli and Davson in 1935.

Q19. Who gave the unit membrane model of plasma membrane?
Answer – Robertson, 1959.

Q20. Give the two alternative name of cell membrane.
Answer – Plasma membrane and plasmelemma.

Q21. Where are ETS enzymes located in mitochondria?
Answer – Inner membrane

Q22. Give the function of mitochondria.
Answer – ATP formation

Q23. What are cristae?
Answer – Infolds of inner mitochondrial membrane

Q24. What type of DNA do mitochondria have?
Answer – Circular, single molecule and double stranded

Q25. Mention three parts of oxysome.
Answer – Head piece, stalk and base piece (FO & F1)

Q26. Who named mitochondria?
Answer – Benda

Q27. What kind of enzymes is present in the mitochondria?
Answer – Respiratory enzymes

Q28. Name the enzymes oxysomes represent.
Answer – ATPase (ATP Synthetase)

Q29. Which is the most common energy carrier in cells?
Answer – ATP

Q30. Give alternative names of oxysomes.
Answer – Elementary particles, inner membrane subunits, F0-F1 Complex.

Q31. Who introduce the term Endoplasmic Reticulum?
Answer – Porter

Q32. Name two types of ER.
Answer – Rough or granular ER and Smooth or agranular ER

Q33. How does ER arise?
Answer – By out folding of nuclear envelope

Q34. Which type of cells possesses smooth ER?
Answer – Those cells which are engaged in lipid metabolism, such as adipose, brown Fat and adrenocortical cells

Q35. In which cells rough ER is well developed?
Answer – Those cells which are engaged in protein synthesis (enzymes) such as pancreatic cells

Q36. What are rib nucleoprotein particles?
Answer – Ribosomes

Q37. Name two types of ribosomes.
Answer – 70S and 80S

Q38. Where are 70S ribosome found in eukaryotic cells?
Answer – In mitochondria and plastids

Q39. Name the protein factories of the cell.
Answer – Ribosomes

Q40. Which ribosomes produce proteins for export from the cell?
Answer – That is attached to ER

Q41. Name the chemical components of a ribosome.
Answer – RRNA and proteins

Q42. Who discovered Golgi bodies?
Answer – Camillo Golgi

Q43. Golgi apparatus in plants and invertebrate cells consists of several separate units. What are these called?
Answer – Dictyosomes

Q44. Name three types of elements that form the Golgi apparatus.
Answer – Cisternae, tubules and vesicles

Q45. From where do the vesicles of Golgi apparatus arise?
Answer – From Golgi tubules

Q46. What is the origin of Golgi bodies?
Answer – Smooth ER

Q47. Name the organelle commonly referred to as the “traffic police” of the cell.
Answer – Golgi apparatus

Q48. What is glycosylation?
Answer – Linking sugars with proteins

Q49. Who gave the name lysosome?
Answer – De Duve in 1955 because they contain hydrolytic enzymes

Q50. How the cell is protected from the destructive effect of lysosomal enzymes?
Answer – Lysosomal enzymes does not allow the enzymes to go out of the lysosome

Q51. Name different types of lysosomes.
Answer – Primary lysosomes, secondary lysosomes, residual bodies and autophagic

Q52. Give the popular name for the lysosomes.
Answer – Suicide bags or disposal units

Q53. Name the protein of which microtubules in centriole, basal bodies, cilia and flagella are formed.
Answer – Tubulin

Q54. Who discovered the microtubules?
Answer – Robertis and Franchi

Q55. What are Kinetosomes?
Answer – Basal bodies

Q56. Give the main function of centrioles.
Answer – Help organize mitotic apparatus during cell division

Q57. Microtubules are hollow. Is it true?
Answer – Yes

Q58. What MTOC stands for?
Answer – Microtubule organizing centre

Q59. What the study of nucleus is called?
Answer – Karyolgy

Q60. Who discovered the nucleus?
Answer – Robert Brown in 1831

Q61. How many types of histones are found associated with DNA?
Answer – 5 types: H1, H2A, H2B, H3, H4

Q62. What is the composition of chromatin?
Answer – Chromatin is viscous, gelatinous substance and contains DNA, RNA, Histones (basic proteins) and non-histone proteins (acidic proteins)

Q63. What are nucleosomes?
Answer – Bead like enlargements of interphase chromatin fibers

Q64. What is an interphase nucleus?
Answer – Nucleus of non-dividing cell

Q65. Give the role of DNA present in nucleolus?
Answer – Transcription of r RNA

Q66. Which has more DNA and less RNA, euchromatin or heterochromatin?
Answer – Euchromatin

Q67. Where are nucleoli formed at the end of cell division?
Answer – At nucleolar organizing regions of nucleolar chromosomes

Q68. Name two types of chromatin.
Answer – Heterochromatin and Euchromatin

Q69. Who discovered the chromosomes?
Answer – W. Hofsmeister

Q70. Name the part of a chromosome separated by a secondary constriction?
Answer – Satellite

Q71. What is a SAT-Chromosome?
Answer – Chromosome with a satellite

Q72. What are nucleolar chromosomes?
Answer – Which form nucleoli on them

Q73. Name the four types of chromosomes with regard to the position of a centromere.
Answer – Metacentric, Submetacentric, Acrocentric and Telocentric

Q74. Give the terms used for a chromosome with numerous chromonemata.
Answer – Polytene chromosome

Q75. Which component of the chromosomes is responsible for heredity?
Answer – DNA

Q76. Explain heterochromatin.
Answer – Darkly stained regions of chromosomes are called heterochromosome

Q77. Define nucleolar organizing region?
Answer – Chromosomal regions that contains the genes for ribosomal RNAse and induces formation of nucleolus

Q78. Who discovered salivary gland chromosomes?
Answer – E. G. Balbiani in Chironomus.

Q79. In which period of interphase DNA duplicates?
Answer – S-phase (synthetic phase).

Q80. What is G1 period?
Answer – Period between end of mitosis and start of DNA synthesis.

Q81. In which cell mitosis occurs?
Answer – Somatic cells.

Q82. Who proposed the term mitosis?
Answer – W. Flemming in 1882.

Q83. What are different stages of mitosis?
Answer – Prophase, metaphase, anaphase, telophase.

Q84. Which stage of mitosis is of longest duration?
Answer – Prophase.

Q85. What is cytokinesis?
Answer – Division of cytoplasm.

Q86. At which stage centrioles replicate?
Answer – Interphase.

Q87. In which cell meiotic divisions occur?
Answer – Gonadian cells (spermatozoa and ovum).

Q88. What are the various sub stages of meiotic prophase?
Answer – Leptonema, Zygonema, Pachynema, Diploma and diakinesis.

Q89. Who gave the term meiosis?
Answer – J. B. Farmer and J. E. Moore in 1905.