201. Cytokinins have a molecular structure similar to:
Answer: C. adenine
Biology Class 11 Unit 9: Diversity in Plant Functions MCQs
278 multiple choice questions with the correct answer for each. Tap an option to check yourself, or switch on "Show all answers". This is page 5 of 6.
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202. Abscisic acid is synthesized in:
Answer: B. plastids from carotenoids
203. ABA's principal effect is:
Answer: B. inhibition of cell growth, promotion of dormancy and closing stomata under water stress
204. Under water stress ABA causes:
Answer: B. stomata to close
205. Ethylene is a:
Answer: B. simple gaseous hydrocarbon
206. Ethylene stimulates:
Answer: B. fruit ripening and abscission of fruits and leaves
207. The hormone which delays leaf senescence is:
Answer: C. cytokinin (also auxin and gibberellin)
208. A high cytokinin to auxin ratio promotes the formation of:
Answer: B. shoots
209. A low cytokinin to auxin ratio promotes:
Answer: B. roots
210. Movements of plant parts toward or away from a stimulus are called:
Answer: C. tropisms
211. Movement in response to light is:
Answer: B. phototropism
212. Shoots show:
Answer: B. positive phototropism
213. Roots show:
Answer: B. negative phototropism and positive geotropism
214. Shoots show:
Answer: B. negative geotropism
215. Movement in response to touch is:
Answer: C. thigmotropism
216. Climbing plants show:
Answer: C. thigmotropism
217. Growth of fungal hyphae towards nutrients is an example of:
Answer: D. chemotropism
218. The total duration of light in a day is the:
Answer: B. photoperiod
219. The effect of photoperiod on flowering is:
Answer: B. photoperiodism
220. Plants that flower when the photoperiod is less than a critical length are:
Answer: B. short-day plants
221. An example of a short-day plant is:
Answer: C. cocklebur or chrysanthemum
222. An example of a long-day plant is:
Answer: C. spinach or sugar beet
223. An example of a day-neutral plant is:
Answer: C. tomato, bean or rose
224. The actual stimulus for flowering is the uninterrupted:
Answer: B. dark period
225. Short-day plants are actually:
Answer: B. long-night plants
226. Long-day plants are actually:
Answer: B. short-night plants
227. The critical photoperiod for cocklebur is:
Answer: C. 15.5 hours
228. The critical photoperiod for tobacco is:
Answer: B. 14 hours
229. The critical photoperiod for henbane is:
Answer: A. 11 hours
230. Interrupting the long night of a short-day plant with a brief light:
Answer: B. prevents flowering
231. The wavelength of red light effective in preventing flowering of short day plants is:
Answer: B. 660 nm
232. The wavelength of far-red light is:
Answer: B. 730 nm
233. The photoreceptor pigment involved in photoperiodism is:
Answer: C. phytochrome
234. Phytochromes are pigments which are:
Answer: B. proteins with an iron containing non-protein part
235. The form of phytochrome which absorbs red light is:
Answer: B. Pr (P660)
236. Pr on absorbing red light is converted into:
Answer: B. Pfr (P730)
237. Pfr on absorbing far-red light reverts to:
Answer: B. Pr
238. The conversion of Pfr to Pr occurs mainly:
Answer: B. at night
239. A short-day plant requires a ... ratio of Pfr to Pr:
Answer: B. low
240. A long-day plant requires a ... ratio of Pfr to Pr:
Answer: B. high
241. The flowering hormone is called:
Answer: B. florigen
242. Florigen transforms:
Answer: B. vegetative buds into floral buds
243. Promotion of flowering by exposure to low temperature is:
Answer: C. vernalization
244. The low temperature stimulus in vernalization is received by:
Answer: C. shoot apex of a mature plant or the embryo
245. The most effective temperature for vernalization is about:
Answer: B. 4 degrees Celsius
246. Vernalization is required by:
Answer: B. biennial plants
247. Winter wheat is a:
Answer: B. biennial plant
248. The hormone vernalin is actually:
Answer: C. gibberellin
249. Spring wheat sown in February or March is:
Answer: B. an annual plant
250. Winter wheat sown in spring will flower if its seeds are exposed to:
Answer: B. low temperature (4 degrees) for several weeks
About Biology Class 11 Unit 9 MCQs (Federal Board)
These 278 Biology MCQs cover Class 11 Unit 9: Diversity in Plant Functions of the Federal Board (FBISE) HSSC-I (1st Year / Class 11) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. The questions are split over 6 pages of 50. Use the Print button to save this chapter as a PDF.