101. The movement of the RNA polymerase is in the direction:
Answer: B. 5 prime to 3 prime of RNA
Biology Class 11 Unit 13: Chromosome and DNA MCQs
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102. The terminator region consists of GC base pairs followed by:
Answer: B. AT base pairs, forming a GC hairpin and poly U tail
103. The GC hairpin in transcription termination causes:
Answer: B. RNA polymerase to stop synthesis of RNA
104. Eukaryotic newly synthesized mRNA is called:
Answer: B. pre-mRNA or primary transcript
105. In prokaryotes mRNA:
Answer: B. undergoes translation as soon as it is formed
106. The non-coding regions of eukaryotic genes are:
Answer: B. introns
107. The coding regions are called:
Answer: B. exons
108. The 5 prime cap on mRNA is:
Answer: B. 7-methylguanosine triphosphate (7-methyl GTP)
109. The poly-A tail of mRNA is added at the:
Answer: B. 3 prime end, with 30 to 500 adenine nucleotides
110. The cap and tail protect mRNA from:
Answer: B. degradation by phosphatases and nucleases
111. The removal of introns from mRNA is called:
Answer: B. RNA splicing
112. Splicing is catalysed by:
Answer: C. spliceosomes (RNA-protein complex)
113. The exons are joined together by:
Answer: B. RNA ligase
114. The length of mRNA shortens as it enters the cytoplasm due to:
Answer: B. removal of introns by splicing
115. The relationship between amino acid sequence and nucleotide sequence is called the:
Answer: B. genetic code
116. A triplet of bases specifying an amino acid is a:
Answer: B. codon
117. The total number of codons is:
Answer: D. 64
118. The number of codons which do not encode any amino acid:
Answer: C. three (UAA, UAG, UGA)
119. The stop codons are also called:
Answer: B. nonsense codons
120. The start codon is:
Answer: C. AUG which codes for methionine
121. The characteristic of genetic code in which an amino acid is encoded by more than one codon is:
Answer: C. degeneracy
122. Leucine and serine are each encoded by:
Answer: C. six codons
123. The amino acids encoded by a single codon are:
Answer: B. methionine and tryptophan
124. The genetic code is universal, meaning it is:
Answer: A. the same in almost all organisms
125. An exception to universality is found in the genetic code of:
Answer: B. mitochondrial DNA
126. In mitochondria UGA codes for:
Answer: B. tryptophan
127. The genetic code is read without gaps between codons. This is:
Answer: B. comma-less (no punctuation)
128. Non-overlapping code means:
Answer: B. each base belongs to only one codon
129. The minimum number of tRNA types needed in a cell for a triplet code (excluding stop codons) is:
Answer: C. 61
130. Translation is the synthesis of:
Answer: C. polypeptide from mRNA
131. The four phases of translation are:
Answer: B. activation of amino acids, formation of initiation complex, elongation and termination
132. Amino acids bind to tRNA with the help of:
Answer: B. aminoacyl-tRNA synthetase
133. Amino acids are attached to tRNA at its:
Answer: C. 3 prime CCA end
134. Activation of amino acids requires:
Answer: B. ATP
135. The first tRNA in prokaryotes carries:
Answer: B. N-formylmethionine
136. In eukaryotes the initiating amino acid is:
Answer: B. methionine (unmodified)
137. The initiation complex is formed by:
Answer: B. small ribosomal subunit, mRNA and first aminoacyl-tRNA, then large subunit
138. The P site of the ribosome is the:
Answer: C. peptidyl site
139. The A site of the ribosome is the:
Answer: A. aminoacyl site where new tRNAs bind
140. The E site of the ribosome is the:
Answer: C. exit site where empty tRNAs leave
141. Peptide bonds between amino acids are formed by:
Answer: B. peptidyl transferase
142. The movement of the ribosome along mRNA by one codon is:
Answer: B. translocation
143. The ribosome moves along mRNA in the direction:
Answer: B. 5 prime to 3 prime
144. Translation terminates when which is exposed at the A site?
Answer: C. A stop codon
145. Stop codons are recognized by:
Answer: C. release factors
146. The polypeptide after synthesis enters the Golgi complex for:
Answer: C. further modification
147. A cell can secrete proteins as:
Answer: B. digestive enzymes, hormones, albumins, fibrinogen and antibodies
148. Ribosomes in eukaryotes are:
Answer: B. 80S with 60S and 40S subunits
149. Prokaryotic translation uses how many release factors?
Answer: B. Two
150. Eukaryotic translation uses:
Answer: B. a single release factor
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.