Description : Silencer elements (A) Are trans-acting factors (B) Are present between promoters and the structural genes (C) Decrease the expression of some structural genes (D) Encode specific repressor proteins
Last Answer : Answer : C
Description : Inducers and repressors are (A) Enhancer and silencer elements respectively (B) Trans-acting factors (C) Cis-acting elements (D) Regulatory proteins
Last Answer : Answer : B
Description : In split genes, the coding sequences are called (a) exons (b) cistrons (c) introns (d) operons
Last Answer : (d) operons.
Description : In split genes, the coding sequences are called (a) exons (b) cistrons (c) introns (d) operons.
Last Answer : (a) exons
Description : The coding sequences found in split genes are called a) Operons b) introns c) exons d) cistrons
Last Answer : c) exons
Description : Introns in genes (A) Encode the amino acids which are removed during post-translational modification (B) Encode signal sequences which are removed before secretion of the proteins (C) Are the non-coding sequences which are not translated (D) Are the sequences that intervene between two genes
Description : The eukaryotic genome differs from the prokaryotic genome because (a) the DNA is complexed with histone in prokaryotes (b) the DNA is circular and single stranded in prokaryotes (c) repetitive sequences are present in eukaryotes (d) genes in the former case are organised into operons.
Last Answer : (b) the DNA is circular and single stranded in prokaryotes
Description : In the regulation of genes: a. more than 90% of the base sequences in human DNA have not known function b. extrons are the part of the gene that code for amino acids found in the final proteins. c. introns usually begins with the nucleotide sequence GT d. all above
Last Answer : all above
Description : Non-coding sequences in a gene are known as (A) Cistrons (B) Nonsense codons (C) Introns (D) Exons
Description : Folding of newly synthesized proteins is accelerated by (A) Protein disulphide isomerase (B) Prolyl cis-trans isomerase (C) Chaperonins (D) All of these
Last Answer : Answer : D
Description : Two dominant nonallelic genes are 50 map units apart. The linkage is (a) cis type (b) trans type (c) complete (d) absent/incomplete.
Last Answer : (d) absent/incomplete.
Description : When two genetic loci produce identical phenotypes in cis and trans position, they are considered to be (a) multiple alleles (b) the parts of same gene (c) pseudoalleles (d) different genes
Last Answer : (c) pseudoalleles
Description : . A and B are stereoisomers. They are nonsuperimposable and are mirror images of one another. Which of the following best describes the relationship between A and B? (a) structural isomers (b) enantiomers (c) cis-trans isomers (d) diastereomers
Last Answer : enantiomers
Description : The regulatory i gene of lac operon (A) Is inhibited by lacotse (B) Is inhibited by its own product, the repressor protein (C) Forms a regulatory protein which increases the expression of downstream structural genes (D) Is constitutively expressed
Description : Lac operon is a cluster of (A) Three structural genes (B) Three structural genes and their promoter (C) A regulatory gene, an operator and a promoter (D) A regulatory gene, an operator, a promoter and three structural genes
Description : Rhodopsin contains opsin and (A) 11-cis-retinal (B) 11-trans-retinal (C) All-cis-retinal (D) All trans-retinal
Last Answer : Answer : A
Description : Gene and cistron words are sometimes used synonymously because (a) one cistron contains many genes (b) one gene contains many cistrons (c) one gene contains one cistron (d) one gene contains no cistron
Last Answer : (b) one gene contains many cistrons
Description : Gene and cistron words are sometimes used synonymously because (a) one cistron contains many genes (b) one gene contains many cistrons (c) one gene contains one cistron (d) one gene contains no cistron.
Last Answer : c) one gene contains one cistron
Description : Genes that are involved in turning on or off the transcription of a set of structural genes are called (a) redundant genes (b) regulatory genes (c) polymorphic genes (d) operator genes.
Last Answer : (d) operator genes.
Description : .The lac operon consists of (a) four regulatory genes only (b) one regulatory gene and three structural genes (c) two regulatory genes and two structural genes (d) three regulatory genes and three structural genes.
Last Answer : (b) one regulatory gene and three structural genes
Description : Which one of the following is NOT part of an operon? a. Regulatory gene b. Operator c. Promoter d. Structural genes
Last Answer : d. Structural genes
Description : cis-acting elements include (A) Steroid hormones (B) Calcitriol (C) Histones (D) Silencers
Description : Proto-oncogenes are: B A. DNA sequences in cells that are oncogenes themselves B. Cellular copies of genes that were first found in oncogenic retroviruses C. DNA viral sequences that are known to infect human cells D. Bacterial DNA counterparts
Last Answer : Cellular copies of genes that were first found in oncogenic retroviruses
Description : DNA elements, which can switch their position, are called (a) cistrons (b) transposons (c) exons (d) introns.
Last Answer : (b) transposons
Description : Prosthetic group in cone cell phototreceptors is (A) Iodine (B) Opsin (C) 11-cis-retinal (D) all-trans-retinal
Description : When light falls on rod cells (A) All-cis-retinal is converted into all-trans-retinal (B) 11-cis-retinal is converted into 11-trans-retinal (C) 11-trans-retinal is converted into all-transretinal (D) 11-cis-retinal is converted into all-trans-retinal
Description : On exposure to light rhodopsin forms (A) All trans-retinal (B) Cis-retinal (C) Retinol (D) Retinoic acid
Description : trans-acting factors include (A) Promoters (B) Repressors (C) Enhancers (D) Silencers
Description : Lac operon of E. coli contains _______ is continuity. (A) Regulator and operator genes only (B) Operator and structural genes only (C) Regular and structural genes only (D) Regulator, operator and structural genes
Description : Suppressor tRNAs can neutralize the effects of mutations in (A) Structural genes (B) Promoter regions (C) Enhancer elements(D) All of these
Description : Suppressor mutations occur in (A) Structural genes (B) Promoter regions (C) Silencer elements (D) Anticodons of tRNA
Description : .Expressed Sequence Tags (ESTs) refers to (a) novel DNA sequences (b) genes expressed as RNA (c) polypeptide expression (d) DNA polymorphism.
Last Answer : (b) genes expressed as RNA
Description : What is the term used for a segment of DNA with one or more genes in the centre and the twoends carrying inverte d repeat sequences of nucleotides? A- Plasmid B- Transposon C- Insertion sequence D- None of these
Last Answer : Transposon
Description : The development of global regulatory systems in prokaryotes A- determines the exact location of the cell on the globe B- aids in DNA replication C- .determines the exact location of the replication site D- regulates many genes under varying environmental conditions
Last Answer : regulates many genes under varying environmental conditions
Description : DNA contains some palindromic sequences which (A) Mark the site for the formation of replication forks (B) Direct DNA polymerase to turn back to replicate the other strand (C) Are recognized by restriction enzymes (D) Are found only in bacterial DNA
Description : Satellite DNA contains (A) Highly repetitive sequences (B) Moderately repetitive sequences (C) Non-repetitive sequences (D) DNA-RNA hybrids
Description : The coding sequences in lac operon include (A) i gene (B) i gene, operator locus and promoter (C) z, y and a genes (D) i, z, y and a genes
Description : Why Deinococcusradiodurans is able to survive massive exposure to radiation? A- .Because it produces a thick shell which acts as a shield from the radiation B- Because it has unique DNA repair ... its cellwall contains radioactive elements D- Because it has many copies of genes encoding DNA repair
Last Answer : Because it has many copies of genes encoding DNA repair
Description : All of the following statements about eukaryotic promoters are true except (A) They may be located upstream or down stream from the structural gene (B) They have two consensus sequences ( ... (D) Mutations in promoter region can decrease the efficiency of transcription of the structural gene
Description : Which can show the cis-trans isomerism:
Last Answer : Which can show the cis-trans isomerism: A. `CICH_(2)CH_(2)CI` B. `CI_(2)C=C=CH_(2)` C. `CH_(2)C=CCI_(2)` D. CICH=C=CHCI
Description : Which of the following combination of axial & equitorial bonds show Cis or Trans orientation in Dimethyl cyclohexane. (i) 1e, 2e (ii) 1e, 3e (iii) 1e,
Last Answer : Which of the following combination of axial & equitorial bonds show Cis or Trans orientation in Dimethyl cyclohexane. ... 3a (vi) 1e, 4a (vii) 1a, 3a
Description : In which compound, Cis-Trans nomenclature cannot be used?
Last Answer : In which compound, Cis-Trans nomenclature cannot be used? A. `CH_(3)-CH=CH-CH_(3)` B. `CH_(3)-CH=CH-COOH` C. D. `C_(6)H_(5)-CH=CH-CHO`
Description : Cis-trans isomerism is found in square planar complexes of molecular formula: (a and b are monodentate ligands)
Last Answer : Cis-trans isomerism is found in square planar complexes of molecular formula: (a and b are monodentate ligands) A. ` ... . `Ma_(2)b_(2)` D. `Mab_(3)`
Description : Why cis isomers are polar and trans are not?
Last Answer : Need answer
Description : what is indicated by the prefixes cis- and trans-?
Last Answer : The type of stereoisomer
Description : Among Cis and Trans structure of Hex-2-ene which has higher boiling point and why?
Last Answer : Ans: The dipole moment of a molecule depends upon dipole-dipole interactions. Since cis-isomer has higher dipole moment, therefore it has higher boiling point.
Description : The retinal pigment epithelium (RPE): a. is sensitive to hypervitaminosis A b. isomerizes all-trans-retinal to 11-cis-retinol c. does not undergo mitosis in response to injury d. secrets the outer layer of the basal lamina that forms the Bruch's membrane.
Last Answer : isomerizes all-trans-retinal to 11-cis-retinol
Description : During phototransduction: a. hyperpolarisation occurs due to closure of the sodium channels b. 11-cis-retinal molecules are converted to all-trans-retinal c. transducin, a G protein converts GDP to GTP d. all above