Unit 1: Introduction; Callus and Suspension Culture - Practice Quiz

1 Who is regarded as the father of plant tissue culture for proposing the concept of cellular totipotency?

2 The ability of a single plant cell to develop into a complete plant is called:

3 Growing plant cells, tissues, or organs on a nutrient medium under sterile conditions is known as:

4 A small piece of tissue excised from a plant and used to start a culture is called an:

5 Which is the most widely used nutrient medium in plant tissue culture?

6 Which substance is commonly used as a solidifying (gelling) agent in tissue culture media?

7 Which carbon source is most commonly added to plant tissue culture media?

8 The optimum pH range generally maintained in plant tissue culture media is:

9 Culturing isolated plant organs such as roots or shoots on a nutrient medium is called:

10 A plant cell that has had its cell wall removed enzymatically is called a:

11 The formation of organs such as shoots and roots from cultured cells or tissues is known as:

12 A high cytokinin to auxin ratio in the medium generally promotes the formation of:

13 Which chemical is commonly used as a surface sterilant for plant explants?

14 Sterilization of nutrient media is most commonly done using an:

15 Aseptic transfer of explants is usually carried out in a:

16 An unorganized, actively dividing mass of undifferentiated cells formed on a medium is called:

17 The transfer of callus to fresh medium at regular intervals to keep it healthy is called:

18 A suspension culture consists of cells and cell aggregates growing dispersed in:

19 Suspension cultures are usually kept in constant motion using a:

20 A callus that is soft, watery, and breaks apart easily is described as:

21 The concept of totipotency, which forms the theoretical basis of plant tissue culture, was first proposed by which scientist?

22 F.C. Steward's classic experiment demonstrating totipotency used explants derived from which plant tissue?

23 A researcher regenerates an entire plant from a single differentiated somatic cell. This ability of a cell to develop into a complete organism is termed:

24 When a mature, differentiated cell reverts to a meristematic state to form callus, the process is called:

25 The Murashige and Skoog (MS) medium is most notable for its high concentration of which component compared to earlier media?

26 Which carbon source is most commonly added to plant tissue culture media as an energy source?

27 The optimum pH of most plant tissue culture media before autoclaving is generally adjusted to approximately:

28 A high ratio of auxin to cytokinin in the culture medium generally promotes which developmental outcome?

29 Culturing an isolated shoot apical meristem to obtain virus-free plants is an example of:

30 Anther culture is primarily used to produce which type of plants?

31 In tissue culture, the formation of shoots and roots directly from an explant without an intervening callus phase is called:

32 Which of the following best distinguishes somatic embryogenesis from organogenesis?

33 Which chemical is most commonly used as a surface sterilant for plant explants at concentrations of 0.1–1%?

34 Culture media and glassware are most commonly sterilized by autoclaving at which standard conditions?

35 Heat-labile compounds such as certain growth regulators and antibiotics are best sterilized by:

36 During callus subculture, tissue must be transferred to fresh medium periodically mainly to:

37 A callus culture that has been maintained for many subcultures shows changes in chromosome number and morphogenic potential. This phenomenon is known as:

38 A callus that is soft, watery, and easily breaks apart into cells is described as:

39 For establishing a good cell suspension culture, which type of callus is most suitable as the starting material?

40 Cell suspension cultures are maintained under constant agitation on a rotary shaker primarily to:

41 Gottlieb Haberlandt is credited with proposing the concept of cellular totipotency in 1902, yet his own experiments failed to demonstrate it. What was the primary reason his cultured cells did not divide?

42 The first successful demonstration of totipotency, producing a whole plant from a single somatic cell, is attributed to which milestone?

43 A researcher observes that a genetically uniform explant population produces regenerants with variable ploidy and phenotype after prolonged callus phase. This phenomenon and its most likely cause are best described as:

44 MS medium is characterized by a very high total ionic salt concentration compared to earlier media. Which pair of nutrient features is most distinctive of MS relative to White's medium?

45 During autoclaving, sucrose in culture medium can partially hydrolyze and caramelize, and certain compounds degrade. Which practice correctly addresses a heat-labile component?

46 A medium is prepared at pH 5.8 before autoclaving with 0.8% agar. After autoclaving the gel fails to solidify properly. What is the most probable cause?

47 In establishing a meristem-tip culture for virus elimination, why is the excised explant kept extremely small (0.1–0.5 mm, apical dome plus one leaf primordium)?

48 According to the Skoog-Miller model, an explant on medium with a high auxin-to-cytokinin ratio, an intermediate ratio, and a low ratio will respectively favour:

49 Which statement most accurately distinguishes indirect organogenesis from direct somatic embryogenesis?

50 An explant sterilized with 0.1% HgCl for 10 minutes shows near-total tissue browning and death, while 2 minutes gives heavy contamination. The optimal strategy is to:

51 Phenolic browning of freshly cut explants is a common problem. Which combination of measures most directly targets the underlying oxidation mechanism?

52 When maintaining callus by serial subculture, why must the inoculum size and subculture interval be carefully controlled?

53 A callus culture initiated from a dicot stem segment shows vigorous growth only at the cut ends, not along the intact epidermis. This localized proliferation is best explained by:

54 Two callus lines from the same species differ markedly: one is friable, pale, and crumbly; the other is hard, compact, and green with nodular regions. Which interpretation is most accurate?

55 In distinguishing embryogenic from non-embryogenic callus, which set of cytological features characterizes embryogenic callus?

56 To initiate a good single-cell suspension, which starting material and condition combination is most suitable?

57 A batch suspension culture is monitored over time. The characteristic growth pattern of packed cell volume follows which curve, and at which phase should cells be subcultured for best viability?

58 A continuous 'chemostat' type suspension system differs fundamentally from a 'turbidostat' in that:

59 The 'cell viability' of a suspension is often assessed. Which method combination correctly pairs a viability stain with its indication of living cells?

60 A protoplast-derived single cell is cultured to test totipotency but repeatedly fails to divide at low density, though it divides readily at high density. The most rational explanation and remedy is: