Genetics and Evolution
- Which is the "Only enzyme" that has "Capability" to catalyse Initiation, Elongation and Termination in the process of transcription in prokaryotes ? Answer: 2. DNA dependent RNA polymerase In prokaryotes a single DNA-dependent RNA polymerase catalyses initiation (with sigma factor), elong... 1
- DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as : Answer: 2. Repetitive DNA DNA fingerprinting identifies differences in specific regions of DNA called repetitive DNA. These regions, such as... 1
- Identify the correct statement. Answer: 2. RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria. Check each statement. Capping adds me... 1
- What is the role of RNA polymerase III in the process of transcription in eukaryotes ? Answer: 2. Transcribes tRNA, 5s rRNA and snRNA In eukaryotes: RNA polymerase I transcribes 28S, 18S and 5.8S rRNA; RNA polymerase II transcr... 1
- Which of the following RNAs is not required for the synthesis of protein ? Answer: 4. siRNA Protein synthesis (translation) needs mRNA (template), tRNA (carries amino acids) and rRNA (ribosome structure and catalysi... 1
- Complete the flow chart on central dogma.(a) DNA (with circular arrow) --(b)--> mRNA --(c)--> (d) Answer: 3. (a)-Replication; (b)-Transcription; (c)-Translation; (d)-Protein The central dogma is DNA to mRNA to protein. The circular arrow... 1
- Mutations in plant cells can be induced by : Answer: 3. Gamma rays Mutations are induced by mutagens such as gamma rays, which are ionising radiation and damage DNA. Kinetin and zeatin... 1
- DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as : Answer: 2. Bright orange bands Ethidium bromide intercalates between DNA bases. Under UV light, the stained DNA fragments in an agarose gel... 1
- The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called : Answer: 3. Punnett square The diagram used to show gametes of the parents, the zygotes, and the F1 and F2 genotypes is the Punnett square, d... 1
- Experimental verification of the chromosomal theory of inheritance was done by : Answer: 4. Morgan Sutton and Boveri proposed the chromosomal theory of inheritance. Its experimental verification was done by Thomas Hunt Mo... 1
- Which of the following statements is correct ? Answer: 1. Adenine pairs with thymine through two H-bonds. In DNA, adenine pairs with thymine by two hydrogen bonds, and guanine pairs with... 1
- If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6×10^9 bp, then the length of the DNA is approximately : Answer: 3. 2.2 meters Length = number of bp x distance per bp. L = 6.6×10⁹×0.34×10⁻⁹\ m = 2.244\ m≈ 2.2\ m So the answer is about 2.2 metres... 1
- How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits ? Answer: 3. 14 Mendel selected 14 true-breeding pea varieties, which formed seven pairs. Each pair differed in only one character with contra... 1
- Name the enzyme that facilitates opening of DNA helix during transcription. Answer: 4. RNA polymerase During transcription, RNA polymerase itself unwinds the DNA helix locally and synthesises RNA. DNA helicase opens... 1
- The first phase of translation is : Answer: 3. Aminoacylation of tRNA Key idea: Translation begins with charging of tRNA. The first phase is aminoacylation: an amino acid is ac... 1
- Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups. Answer: 3. When I^A and I^B are present together, they express same type of sugar. Key idea: In AB blood group, I^A and I^B are codominant a... 1
- Select the correct match. Answer: 3. Sickle cell anaemia - Autosomal recessive trait, chromosome-11 Key idea: Recall the mode of inheritance of each disorder. Haemoph... 1
- The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by : Answer: 3. Alfred Sturtevant Key idea: Alfred Sturtevant used recombination frequency as a measure of the distance between genes. Morgan dis... 1
- Match the following genes of the Lac operon with their respective products :(a) i gene (i) β-galactosidase(b) z gene (ii) Permease(c) a gene (iii) Repressor(d) y gene (iv) TransacetylaseSelect the correct option. Answer: 3. (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii) Key idea: Lac operon: i gene codes for repressor; z for beta-galactosidase; y for permease... 1
- Expressed Sequence Tags (ESTs) refers to : Answer: 1. Genes expressed as RNA Key idea: ESTs identify genes that are expressed as RNA. In the genome-sequencing approach, one method seq... 1
- What is the genetic disorder in which an individual has an overall masculine development, gynaecomastia, and is sterile ? Answer: 2. Klinefelter's syndrome Key idea: Klinefelter's syndrome is XXY. The individual is male with overall masculine development but als... 1
- Which of the following features of genetic code does allow bacteria to produce human insulin by recombinant DNA technology ? Answer: 3. Genetic code is nearly universal Key idea: The universality of the genetic code lets one organism read another's genes. Since the... 1
- Under which of the following conditions will there be no change in the reading frame of following mRNA ?5' AACAGCGGUGCUAUU 3' Answer: 4. Deletion of GGU from 7 ^th , 8 ^th and 9 ^th positions Key idea: A change that adds or removes a multiple of 3 bases keeps the re... 1
- What map unit (Centimorgan) is adopted in the construction of genetic maps ? Answer: 3. A unit of distance between genes on chromosomes, representing 1% cross over. One map unit (centimorgan) is the distance between g... 1