201. Mice which die are those injected with:
Answer: B. (i) and (iv)
Biology Class 11 Unit 13: Chromosome and DNA MCQs
228 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 5.
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202. In the mixture (iv) live S-type bacteria are found in the dead mice because of:
Answer: B. transformation of R-type by a substance from dead S-type
203. The substance responsible was later identified to be:
Answer: D. DNA
204. The scientist who identified it was:
Answer: B. Avery, MacLeod and McCarty
205. After one generation the DNA band is:
Answer: C. in the middle (hybrid)
206. After two generations, the bands are:
Answer: C. one at the top and one in the middle
207. This result supports:
Answer: C. semi-conservative replication
208. The experiment was done by:
Answer: B. Meselson and Stahl
209. The continuous strand is the:
Answer: B. leading strand
210. The short pieces are called:
Answer: B. Okazaki fragments
211. The enzyme that joins the pieces is:
Answer: C. ligase
212. The enzyme that provides the starting short RNA is:
Answer: C. primase
213. The shortening is due to removal of:
Answer: B. introns by splicing
214. The process occurs in the:
Answer: C. nucleus
215. The cap and tail protect mRNA from:
Answer: B. degradation by nucleases and phosphatases
216. The splicing enzyme complex is the:
Answer: C. spliceosome
217. The start codon is:
Answer: B. AUG, coding for methionine
218. The stop codon is:
Answer: D. UAA
219. The number of amino acids in the polypeptide formed is:
Answer: B. 3
220. The tRNA anticodon for the codon AGC would be:
Answer: B. UCG
221. The syndrome is:
Answer: C. Down syndrome
222. The chromosomal constitution is:
Answer: B. trisomy 21
223. The cause is:
Answer: B. non-disjunction of chromosome 21 in maternal meiosis
224. A suitable test during pregnancy to detect it is:
Answer: B. amniocentesis
225. This regulation is described by:
Answer: B. the lac operon
226. In the absence of lactose the repressor binds to the:
Answer: B. operator
227. In the presence of lactose the repressor is:
Answer: B. inactivated by binding the inducer
228. The enzymes produced include:
Answer: B. beta-galactosidase, permease and transacetylase
About Biology Class 11 Unit 13 MCQs (Federal Board)
These 228 Biology MCQs cover Class 11 Unit 13: Chromosome and DNA 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 5 pages of 50. Use the Print button to save this chapter as a PDF.