Unit 7: Anther culture (Androgenesis) - Practice Quiz

BTY559 — Biotechnology Laboratory-Ii 60 Questions
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1 What is androgenesis in plant tissue culture?

to isolate and inoculate anthers for haploid production Easy
A. Development of haploid plants from the male gametophyte (pollen/anther)
B. Development of plants from unfertilized ovules
C. Formation of roots from leaf tissue
D. Multiplication of diploid somatic cells

2 Anther culture is primarily used to produce plants with which chromosome number?

to isolate and inoculate anthers for haploid production Easy
A. Diploid
B. Haploid
C. Triploid
D. Tetraploid

3 The male reproductive part of a flower that is excised for anther culture is the:

to isolate and inoculate anthers for haploid production Easy
A. Anther
B. Ovary
C. Sepal
D. Stigma

4 Which cells inside the anther give rise to haploid plants during androgenesis?

to isolate and inoculate anthers for haploid production Easy
A. Tapetal cells
B. Vascular cells
C. Epidermal cells
D. Microspores (immature pollen)

5 The most suitable stage of pollen development for successful anther culture is generally the:

to isolate and inoculate anthers for haploid production Easy
A. Uninucleate (mid to late) microspore stage
B. Meiotic tetrad stage
C. Fully germinated pollen tube stage
D. Mature bicellular pollen stage

6 Before inoculation, anthers are usually surface sterilized to:

to isolate and inoculate anthers for haploid production Easy
A. Increase the ploidy level
B. Stimulate flowering
C. Add nutrients to the tissue
D. Remove surface microbial contamination

7 Which of the following is a commonly used surface sterilant for flower buds in anther culture?

to isolate and inoculate anthers for haploid production Easy
A. Sodium hypochlorite / mercuric chloride
B. Glacial acetic acid
C. Sodium hydroxide
D. Concentrated sulphuric acid

8 During anther isolation, the flower bud is opened to carefully remove which structure attached to the anther?

to isolate and inoculate anthers for haploid production Easy
A. The style
B. The petal
C. The pedicel
D. The filament

9 Why should the anther be kept free of filament and other floral tissue during inoculation?

to isolate and inoculate anthers for haploid production Easy
A. To speed up petal growth
B. To avoid regeneration of diploid plants from somatic tissue
C. To increase seed set
D. To prevent the anther from drying

10 Anther inoculation is carried out under aseptic conditions inside a:

to isolate and inoculate anthers for haploid production Easy
A. Water bath
B. Laminar air flow cabinet
C. Open bench top
D. Domestic refrigerator

11 Which nutrient medium is most commonly used as the basal medium for anther culture?

to isolate and inoculate anthers for haploid production Easy
A. Murashige and Skoog (MS) medium
B. Luria-Bertani (LB) broth
C. Potato dextrose agar
D. Nutrient agar

12 A simple way to check the correct pollen stage before inoculation is to:

to isolate and inoculate anthers for haploid production Easy
A. Squash a test anther and stain it with acetocarmine for microscopy
B. Count the number of petals
C. Measure the pH of the anther
D. Weigh the flower bud

13 A cold pretreatment (e.g., ) of flower buds before anther culture is often used to:

to isolate and inoculate anthers for haploid production Easy
A. Increase the ploidy
B. Improve the induction of androgenesis
C. Kill the microspores
D. Sterilize the anthers

14 The haploid plants produced through anther culture can be made homozygous diploid by treatment with:

to isolate and inoculate anthers for haploid production Easy
A. Colchicine
B. Auxin only
C. Ethylene
D. Sodium chloride

15 Doubled haploid plants obtained after chromosome doubling are valuable in breeding because they are:

to isolate and inoculate anthers for haploid production Easy
A. Completely homozygous (pure lines)
B. Triploid and sterile
C. Highly heterozygous
D. Genetically identical to weeds

16 Which term describes the direct formation of embryos from cultured microspores or anthers?

to isolate and inoculate anthers for haploid production Easy
A. Androgenic embryogenesis
B. Micropropagation of shoots
C. Somatic hybridization
D. Protoplast fusion

17 Which of the following crops is classically used as a model for successful anther culture?

to isolate and inoculate anthers for haploid production Easy
A. Banana
B. Mango
C. Tobacco (Nicotiana tabacum)
D. Coconut

18 After inoculation, anther cultures are typically incubated:

to isolate and inoculate anthers for haploid production Easy
A. Under controlled temperature with a suitable light regime
B. In complete darkness at
C. In direct outdoor sunlight without control
D. In boiling water

19 A major advantage of using anther culture in plant breeding programmes is that it:

to isolate and inoculate anthers for haploid production Easy
A. Guarantees polyploid seeds
B. Eliminates the need for any medium
C. Shortens the time needed to obtain homozygous lines
D. Produces only male sterile plants

20 An undesirable outcome sometimes seen in anther culture, where regenerated plants are not uniformly haploid, is due to:

to isolate and inoculate anthers for haploid production Easy
A. Cold pretreatment of buds
B. Use of MS medium
C. Excess sterilization of the medium
D. Regeneration from diploid anther wall tissue

21 During anther culture, haploid plants develop primarily because the cultured cells originate from which structure?

to isolate and inoculate anthers for haploid production Medium
A. Nucellar tissue of the ovule
B. Somatic cells of the anther wall
C. Microspores (pollen mother cells' products)
D. Diploid tapetal cells

22 Why is the correct developmental stage of the microspore considered the single most critical factor for successful anther culture?

to isolate and inoculate anthers for haploid production Medium
A. Older microspores contain more auxin for callus growth
B. Mature pollen divides faster and gives more embryos
C. The tapetum is thickest at the mature stage and nourishes embryos
D. Only microspores at the uninucleate stage can be reprogrammed toward embryogenesis

23 A researcher wants to quickly estimate microspore stage before culture. Which practical correlation is most commonly used in the field?

to isolate and inoculate anthers for haploid production Medium
A. Anther colour after autoclaving indicates the stage
B. Root length of the donor plant predicts the stage
C. Number of stamens per flower reflects ploidy
D. Flower bud length or petal-to-sepal ratio correlates with microspore stage

24 Before inoculation, flower buds are commonly surface sterilized and then held at low temperature (around ) for a few days. What is the main purpose of this cold pretreatment?

to isolate and inoculate anthers for haploid production Medium
A. It sterilizes the anthers by killing surface bacteria
B. It doubles the chromosome number directly
C. It acts as a stress trigger that diverts microspores toward the sporophytic (embryogenic) pathway
D. It causes the anthers to release more nectar

25 While excising anthers, a technician often discards buds where filaments are long and anthers have dehisced. Why?

to isolate and inoculate anthers for haploid production Medium
A. Long filaments carry more contaminating fungi
B. Long filaments block absorption of medium
C. Dehisced anthers are diploid and cannot form haploids
D. Dehisced anthers contain mature pollen that rarely responds to culture

26 During excision, care is taken to remove the filament completely before placing anthers on medium. What is the main reason?

to isolate and inoculate anthers for haploid production Medium
A. Filament (somatic diploid tissue) can proliferate and give diploid callus, masking haploid regenerants
B. Removing the filament reduces the anther's water content
C. The filament is the site of pollen tube growth
D. The filament secretes ethylene that inhibits growth

27 In a routine protocol, buds are surface sterilized rather than the individual anthers. Which reasoning best supports this practice?

to isolate and inoculate anthers for haploid production Medium
A. Buds must be sterilized to trigger dehiscence
B. The enclosed anthers stay sterile inside the bud, so sterilizing the intact bud avoids damaging the delicate anthers
C. Individual anthers absorb too much sterilant and become diploid
D. Anthers are resistant to sterilants and cannot be cleaned individually

28 A student obtains many plants from anther culture but finds most are diploid, not haploid. What is the most likely explanation?

to isolate and inoculate anthers for haploid production Medium
A. Regeneration occurred from diploid anther wall/connective tissue rather than microspores
B. The buds were too young
C. The cold pretreatment was too long
D. The medium contained too much sucrose

29 Which combination of plant growth regulators is typically effective for inducing androgenesis in many species?

to isolate and inoculate anthers for haploid production Medium
A. Ethephon combined with ethylene
B. Abscisic acid alone
C. A balance of an auxin and a cytokinin, adjusted per species
D. Only gibberellic acid at high concentration

30 Haploid plants regenerated from anther culture are often treated with colchicine. What is the objective?

to isolate and inoculate anthers for haploid production Medium
A. To sterilize the plantlets against fungal infection
B. To double the chromosome number and obtain homozygous diploid (doubled haploid) plants
C. To induce flowering earlier
D. To convert diploids back into haploids

31 In anther culture, activated charcoal is sometimes added to the medium. Its main role is to:

to isolate and inoculate anthers for haploid production Medium
A. Increase the osmotic pressure of the medium
B. Provide a carbon source for microspore growth
C. Supply nitrogen for embryo development
D. Adsorb inhibitory phenolics and browning compounds released by the anthers

32 Which cytological verification is most direct for confirming that regenerated plantlets are haploid?

to isolate and inoculate anthers for haploid production Medium
A. Observing flower colour
B. Weighing the fresh biomass
C. Measuring plant height
D. Counting chromosome number in root-tip mitotic cells

33 Why is the physiological condition of the donor plant important for anther culture success?

to isolate and inoculate anthers for haploid production Medium
A. Healthy, well-grown donor plants under optimal conditions yield more responsive microspores
B. Donor age has no effect on microspore response
C. Only diseased plants produce embryogenic anthers
D. Water-stressed plants always give the highest yields

34 A key advantage of doubled haploids produced via anther culture over conventional inbreeding is that:

to isolate and inoculate anthers for haploid production Medium
A. No genetic variation is ever produced
B. The plants are always triploid and sterile
C. Complete homozygosity is achieved in a single generation instead of many
D. They eliminate the need for a donor plant

35 In some protocols microspores are isolated from anthers and cultured directly (isolated microspore culture) instead of whole anthers. One major benefit is:

to isolate and inoculate anthers for haploid production Medium
A. It removes the need for any culture medium
B. It guarantees triploid embryos
C. It avoids interference from diploid anther wall tissue, reducing diploid regenerants
D. It eliminates the requirement for the correct microspore stage

36 During inoculation, anthers are usually placed so the locule side contacts the medium, avoiding pressure that ruptures them. Why avoid rupture?

to isolate and inoculate anthers for haploid production Medium
A. Rupture causes the medium to solidify
B. Prematurely released microspores are exposed and often die or fail to develop
C. Ruptured anthers turn diploid
D. Ruptured anthers release too much cytokinin

37 Which stress pretreatment, besides cold, is frequently applied to buds/anthers to enhance androgenic induction?

to isolate and inoculate anthers for haploid production Medium
A. Freezing at
B. Immersion in strong acid
C. Continuous darkness for two months
D. Heat shock (e.g., for a short period)

38 The phenomenon where cultured anthers produce plants that are a mixture of haploid, diploid and aneuploid cells is called:

to isolate and inoculate anthers for haploid production Medium
A. Somatic embryogenesis
B. Chromosomal (ploidy) chimerism / mixoploidy
C. Organogenesis
D. Cybridization

39 Why are low light or dark conditions often used during the early induction phase of anther culture?

to isolate and inoculate anthers for haploid production Medium
A. Darkness supplies carbon to the microspores
B. Light is completely lethal to all anthers
C. They reduce phenolic browning and favour the switch to embryogenesis
D. Light causes immediate chromosome doubling

40 A breeder crosses two parents, then uses anther culture on the F hybrid. What is the main strategic advantage?

to isolate and inoculate anthers for haploid production Medium
A. It converts the F directly into a stable triploid crop
B. It prevents any recombination between parental genes
C. It removes the need to make the initial cross
D. Recombinant gametes are fixed instantly as homozygous doubled-haploid lines for selection

41 During anther culture, a researcher observes that anthers inoculated at the late uninucleate to early binucleate microspore stage give the highest androgenic response, while anthers taken at the mature pollen stage fail completely. What is the primary reason for this stage-dependence?

to isolate and inoculate anthers for haploid production Hard
A. Only microspores at this developmental window can be diverted from the gametophytic pathway to the sporophytic (embryogenic) pathway
B. The anther wall at the mature stage secretes ethylene which is toxic to the surrounding culture medium
C. Late uninucleate microspores possess thicker exine that mechanically protects them during dissection and plating
D. Mature pollen grains contain higher concentrations of endogenous cytokinins that block callus induction on the medium

42 A cold pretreatment (e.g., for several days) of flower buds prior to anther inoculation frequently increases embryo yield. Which mechanism best explains this stress-induced enhancement?

to isolate and inoculate anthers for haploid production Hard
A. Cold stress promotes symmetric division of the microspore and blocks the vegetative-generative asymmetry that leads to pollen
B. Cold triggers rapid endoreduplication so that all microspores become spontaneously diploid before plating
C. Cold pretreatment sterilizes the buds, reducing the fungal contamination that otherwise destroys cultures
D. Cold stress permanently kills the tapetum, releasing large amounts of stored sucrose into the anther locule

43 In an anther culture experiment, a large fraction of the regenerated plants turn out to be diploid rather than the expected haploid. Assuming the microspores were correctly staged, what is the most likely source of these diploids?

to isolate and inoculate anthers for haploid production Hard
A. Use of an excessively high sucrose concentration that induced polyploidy in the microspores
B. Contamination of the medium with -D which doubles the ploidy of any explant it contacts
C. Regeneration from the diploid somatic tissue of the anther wall or connective rather than from the microspores
D. Fusion of two adjacent haploid microspores inside the anther locule during plating

44 To confirm that a regenerated plantlet from anther culture is genuinely of microspore (gametic) origin and not somatic, which approach is most rigorous?

to isolate and inoculate anthers for haploid production Hard
A. Counting chromosomes to confirm the plant is diploid rather than tetraploid
B. Observing whether the plantlet forms roots faster than a seed-derived control
C. Molecular marker analysis showing homozygosity/hemizygosity at heterozygous parental loci
D. Measuring the height of the regenerated plant relative to the donor plant

45 A protocol calls for surface sterilization of intact flower buds rather than isolated anthers before dissection. What is the principal rationale for sterilizing the whole bud?

to isolate and inoculate anthers for haploid production Hard
A. The sterilant chemically induces the microspore reprogramming needed for embryogenesis
B. Whole buds retain more moisture, preventing the anthers from desiccating during sterilization
C. Isolated anthers cannot withstand any contact with sterilant, so the bud must absorb it first
D. The enclosed anthers inside an intact bud are already aseptic, so only the outer bud surface needs treatment

46 When inoculating anthers, technicians are warned to avoid damaging or breaking the anther during dissection. Why is an intact, undamaged anther important for androgenesis (as opposed to callus from wounding)?

to isolate and inoculate anthers for haploid production Hard
A. Damaged anthers lose their pigmentation, making it impossible to track developmental stage
B. Injured anthers preferentially regenerate from wounded somatic tissue, increasing diploid somatic escapes
C. Broken anthers release microspores that immediately germinate into pollen tubes rather than embryos
D. Wounding raises the auxin level so high that the entire culture becomes necrotic within hours

47 A researcher wants to determine the correct microspore stage without sacrificing the anthers to be cultured. Which practical correlation is most commonly exploited for staging?

to isolate and inoculate anthers for haploid production Hard
A. The ratio of petal length to sepal length, or bud size/position, correlated to microspore stage by prior cytological calibration
B. The number of anthers per flower, which decreases as microspores mature
C. The pH of the anther locule fluid measured with indicator paper before plating
D. The intensity of green color in the anther, which directly indicates uninucleate microspores

48 In many dicots, anther-culture-derived haploids spontaneously double to diploid, whereas in cereals colchicine treatment is often required. What underlies this need for artificial chromosome doubling?

to isolate and inoculate anthers for haploid production Hard
A. A substantial fraction of embryos/plants remain haploid and sterile, requiring doubling to restore fertility and homozygous diploidy
B. Dicot haploids are always sterile while cereal haploids are always fertile without treatment
C. Colchicine is the auxin required specifically by monocot microspores to begin dividing
D. Cereal haploids are lethal and can only survive if immediately treated with colchicine at plating

49 Adding activated charcoal to the anther culture medium often improves androgenic embryo formation. Which explanation is best supported?

to isolate and inoculate anthers for haploid production Hard
A. It emits far-red light that specifically triggers the sporophytic switch in microspores
B. It provides a carbon source that microspores metabolize directly in place of sucrose
C. It adsorbs inhibitory phenolics and browning compounds released by the anther, and may adsorb excess growth regulators
D. It raises the osmotic potential of the medium, forcing microspores to divide symmetrically

50 A comparison shows that isolated microspore culture generally yields a higher frequency of true haploids than intact anther culture. What is the fundamental advantage of the isolated-microspore approach?

to isolate and inoculate anthers for haploid production Hard
A. It removes the diploid somatic anther tissues, so regenerants arise almost exclusively from gametic cells
B. Isolation eliminates the requirement for sterile technique because single cells resist contamination
C. Isolated microspores no longer need any developmental staging before culture
D. Microspores in isolation absorb colchicine automatically, doubling without treatment

51 In an experiment, anthers plated on a medium with a high auxin:cytokinin ratio produced abundant callus, but the callus mostly regenerated diploid plants. What is the best interpretation?

to isolate and inoculate anthers for haploid production Hard
A. Callus phase increases genetic instability and favors proliferation of diploid somatic cells, promoting somatic escapes and variation
B. Callus formation is impossible from microspores, so the plants must be from seeds
C. Cytokinin was completely absent, so no microspores could survive to form embryos
D. High auxin directly converts every haploid nucleus into a diploid nucleus

52 Two donor-plant batches of identical genotype give very different androgenic responses; one had been grown under short days with high light, the other under stressful low-nutrient conditions. Which conclusion about anther culture is most valid?

to isolate and inoculate anthers for haploid production Hard
A. Genotype is the only factor determining androgenesis, so the difference must be a plating error
B. Microspore competence is fixed at meiosis and cannot be influenced by donor growth conditions
C. The physiological condition and growing environment of the donor plant strongly influence androgenic competence of its microspores
D. Donor-plant condition affects only contamination rates, not embryo yield

53 Why is the term 'androgenesis' specifically appropriate for anther/microspore culture, and how does it contrast with gynogenesis?

to isolate and inoculate anthers for haploid production Hard
A. Androgenesis yields diploids and gynogenesis yields haploids by definition
B. Androgenesis produces haploids from the male gametophyte (microspores/pollen), whereas gynogenesis produces them from the female gametophyte (unfertilized ovule/egg)
C. Androgenesis uses only male (dioecious) plants, while gynogenesis uses only female plants
D. Androgenesis requires fertilization by male gametes, while gynogenesis avoids fertilization

54 A worker reports that anthers dehisced (split open) during dissection and pollen was released onto the medium; subsequent cultures failed. What is the most likely reason for failure?

to isolate and inoculate anthers for haploid production Hard
A. Dehiscence proves the buds were fungally infected before dissection
B. Dehiscence indicates the pollen was already mature, past the responsive uninucleate/early-binucleate stage
C. Open anthers lower the medium pH to lethal levels within minutes
D. Released pollen instantly fertilizes the medium, forming inhibitory zygotes

55 In doubling-haploid breeding, why are anther-culture-derived doubled haploids especially valuable compared with conventional inbreeding to homozygosity?

to isolate and inoculate anthers for haploid production Hard
A. They avoid the need for any field selection because all traits are dominant
B. They achieve complete homozygosity in a single generation, versus many generations of selfing
C. They are always polyploid, giving larger fruit than inbred lines
D. They guarantee heterozygous vigor that inbreeding can never produce

56 Which combination of pretreatment plus medium condition would most rationally be chosen to maximize the sporophytic switch while minimizing somatic-tissue regeneration in a recalcitrant cereal?

to isolate and inoculate anthers for haploid production Hard
A. Cold/starvation stress pretreatment of buds combined with a low-auxin medium favoring direct microspore embryogenesis
B. Prolonged heat pretreatment combined with a very high -D concentration to force callus
C. No pretreatment combined with high cytokinin to keep anther walls dividing
D. High-sucrose osmotic shock combined with continuous bright light to mature the pollen faster

57 'Albino plant' regeneration is a well-known problem in cereal anther culture. What does the frequent recovery of albinos indicate about the process?

to isolate and inoculate anthers for haploid production Hard
A. Albino plants form only when colchicine is applied too early during doubling
B. Albinism proves the plants are diploid somatic escapes rather than haploids
C. Albinism results from excess activated charcoal blocking all light in the culture vessel
D. Microspore-derived cells often carry plastid/chloroplast genome deletions or defects, so regenerants lack functional chloroplasts

58 If a heterozygous donor plant is used for anther culture, what genotypic outcome is expected among the (chromosome-doubled) haploid regenerants, ignoring linkage?

to isolate and inoculate anthers for haploid production Hard
A. Only heterozygotes, identical to the donor plant
B. Only and in a ratio
C. Four homozygous classes—, , , —each in equal proportion
D. A continuous range of partially heterozygous genotypes

59 A lab wants to verify microspore stage rapidly at the bench during dissection. Which staining method is the standard choice for visualizing the nucleus/nuclei to confirm the uninucleate stage?

to isolate and inoculate anthers for haploid production Hard
A. Gram staining of the anther smear to distinguish nuclear membranes
B. Acetocarmine (or DAPI) squash of a sample anther to count microspore nuclei
C. Iodine (I-KI) staining to detect starch in mature pollen only
D. Trypan blue exclusion to confirm microspore viability rather than stage

60 A researcher obtains many embryo-like structures from anther culture but they arrest before forming shoots. Which manipulation is the most logical next step to promote conversion to plantlets?

to isolate and inoculate anthers for haploid production Hard
A. Increase the -D concentration greatly to force the embryos into more callus
B. Return the cultures to prolonged cold to restart the sporophytic switch
C. Transfer embryos to a fresh regeneration medium with an adjusted cytokinin:auxin balance favoring shoot organogenesis
D. Add colchicine immediately to double the arrested embryos before any shoot forms