QUESTION ID:1
During cell cycle, entry in the S-phase is tightly regulated. This is possible because:
A. APC/C promotes ubiquitination of S-phase cyclins and mitotic cyclins, marking them for proteolyses at the mitotic exit.
B. Cyclin B1 helps in the activation of S-phase CDKs only in late G1.
C. As mitotic CDK activity declines in late mitosis, cdc14 phosphatase activates APC/C by dephosphorylating Cdh1, thus promoting formation of APC/Ccdh1
D. Securin keeps S-phase cyclins in inactive state till late G1.
Which one of the options represents all correct statements?
QUESTION ID:2
Thousands of proteins that are synthesized in the cytoplasm are imported into the nucleus through the nuclear pore complex (NPC) every minute. These proteins contain Nuclear Localization Signal (NLS) that direct their selective transport into the nucleus. This nuclear import requires
A. A small monomeric G-protein Ran.
B. A nuclear transport receptor that interacts with the NLS on a cargo protein.
C. A GTPase activating protein (GAP) bound to the chromatin tethered to the nuclear membrane
D. A Guanine Exchange Factor (GEF) bound to the chromatin inside the nucleus.
Which one of the following options represents all correct statements?
QUESTION ID:3
Listeria is a food-borne pathogen that causes mild gastro-intestinal symptoms. To move from one host-cell to another, it polymerizes actin into a comet tail like structure. Listeria can assemble host-cell actin at its rear end because:
A. Listeria has on its surface a protein called Act A
B. Listeria can activate Arp 2/3 complex
C. Listeria has on its surface γ-tubulin
D. Listeria has on its surface myosin II motor
Which one of the following options represents all correct statements?
QUESTION ID:4
The membrane phospholipid structures in bacteria and archaea differ. Which one of the following correctly states the differences between the two?
QUESTION ID:5
Deletion analysis of a promoter region of a gene was carried out to identify the regulatory elements in it. In the figure below, the filled boxes denote the areas of deletion and the observed activities (in arbitrary units) of the promoter are as shown.
Based on the observations, following statements were made:
A. The region between-100 and -50 houses a positive regulatory element.
B. The region between -200 and -250 houses a negative regulatory element
C. The region between -150 and -200 houses a positive regulatory element.
Which one of the following options represents the correct interpretation of the data?
QUESTION ID:6
Following statements were made with respect to transcription in eukaryotes:
A RNA polymerase III synthesizes mRNAs in the nucleoplasm
B. The target promoter for RNA polymerase III is usually represented by a bipartite sequence downstream of the transcription start site.
C. The assembly factors TFIIIA and TFIIIC assist the binding of the positioning factor TFIIIB at the precise location.
D. TFIIIB is the last factor that joins the initiation complex.
E. Phosphorylated Ser residues in the C-terminal domain (CTD) of RNA polymerase II serve as binding sites for mRNA processing enzymes.
Which one of the following options represents the correct combination of the statements?
QUESTION ID:7
The figure below shows the structure of a replication fork.
Based on this information following statements are made:
A. (i) represents the leading strand while (ii), (ii) and (iv) represent the Okazaki fragments.
B. Among the Okazaki fragments, synthesis of (iv) occurs prior to the synthesis of (iii) and (i)
C. Among the Okazaki fragments, synthesis of (ii) occurs prior to the synthesis of (iii) and (iv).
Which one of the following options represents the correct statement(s)?
QUESTION ID:8
Many organisms encode only 18 aminoacyl-tRNA synthetases (aaRS). These organisms lackaars that use Asn or Gln (as one of the substrates) for direct aminoacylation of the tRNAAsnand tRNAGln respectively. Which one of the following statements represents the correct option?
QUESTION ID:9
Ribosomes prepared from a bacterium were fractionated by sucrose density gradient centrifugation (panel i) to separate the 30S, 50S and 70S populations. When the ribosome preparation was incubated individually with either elongation factor-G (EF-G), or a newly identified protein X, Or GTP, the profile remained unchanged. Likewise, no changes were seen in the profile when the ribosomal preparation was incubated with EF-G +
GTP or protein X + GTP. However, when the ribosomal preparation was incubated with protein X, EF-G and GTP together, it resulted in a change of profile which showed a decrease of the 70S peak area and increase in the peak areas for 30S and 50S (panel ii).
Choose the option that defines a correct conclusion from the observations.
QUESTION ID:10
Following statements were made about the post- transcriptional processing of RNA in eukaryotes.
A. Soon after transcription initiation, RNA polymerase II pauses -30 nucleotides downstream from the site of initiation until the Cap structure is added to the 5' end of the nascent pre- mRNA
B. The 5' splice sites are functionally divergent whereas the 3 sites are functionally equivalent.
C. In addition to helping in recognition of the splice sites, the exon definition also functions as a splicing regulator by allowing pairing and linking of adjacent 5 and 3' splice sites.
D. The intron definition mechanism applies only to the larger introns (above 500 nucleotides length) and assists in achieving alternate splicing.
E. The splicing reactions carried out in vitro have revealed that the first and second trans-esterification reactions are reversible.
Which one of the following combination of statements is correct?
QUESTION ID:11
In the diagram below, the dotted line marks the point of initiation of bidirectional replication
A. On the right side of the dotted line, leading strand
synthesis occurs using the upper strand a the template.
B. On the right side of the dotted line, leading strand
synthesis occurs using the lower strand a the template.
C. A ligase deficient (lig-) mutant would affect replication of the upper strand on the left side
of the dotted line.
D. A ligase deficient (lig-) mutant would affect replication of the lower strand on the left side of the dotted line.
Which one of the following options represents the combinations of the correct statements?
QUESTION ID:12
Bacterial infections are generally divided into two broad classes: intracellular and extracellular bacterial infections. Given below are some of the properties, which are applicable for bacterial infections.
A Humoral immune response is the main protective response against extracellular bacteria.
B. Innate immunity is not effective against intracellular bacterial pathogens.
C. Bacterial endotoxins do not induce an innate immune response.
D. Intracellular bacterial infections generally induce a cell-mediated immune response resulting in secretion of cytokines which activate macrophages.
Which one of the following combination of statements is correct?
QUESTION ID:13
In the table below Column A lists ligands and Column B lists classes of receptors
Which one is the correct match?
QUESTION ID:14
Cells are physically linked to one another and to extracellular
matrix through their cytoskeleton and this impart strength and rigidity of
tissues and organs. Most of the animal cells have three types of
cytoskeletal filaments, which are listed in Column A. The possible
functions are listed in Column B.
Which one is the correct
match?
QUESTION ID:15
Acetylcholine is a potent neurotransmitter, which is released from the neurons. After release they diffuse across the synaptic cleft and combine with nicotinic acetylcholine receptor molecules in the membrane of the postsynaptic cell. The interaction of acetylcholine with the nicotinic acetylcholine receptor produces large transient increase in the permeability of the membrane to specialized ions resulting in signal transduction for nerve impulse. Acetylcholine receptor is a
QUESTION ID:16
Strain A mice were crossed with strain B mice and first generation F1 mice were obtained, i.e.(A x B)F1. A scientist then implanted thymectomized and irradiated (A x B)F1 mice with a B-type thymus and then reconstituted the animals immune system with an intravenous infusion of (A x B)F1 bone marrow cells. The chimeric mice were infected with lymphocytic choriomeningitis virus (LCMV) and the spleen T cells were then tested for their ability to kill LCMV-infected target cells from the strain A or strain B mice.Which one of the following is the correct outcome of the experiment
QUESTION ID:17
The anterior-posterior compartment of each segment of
Drosophila is defined by wingless and engrailed genes. The following statements
are given towards explaining their regulation:
A. Wingless is a secretory factor
Which one of the following options has all the correct statements towards the regulation of anterior-posterior compartment of segments?
QUESTION ID:18
Following statements are being made regarding specification determination during animal development:
A. During the course of commitment, the cell may not appear different from its nearest or most distant neighbours in the embryo and show no visible signs of differentiation; but its developmental fate is restricted.
B. At the stage of specification, cell commitment is not labile.
C. A cell or tissue is determined when it is capable of differentiating autonomously even when placed into another region of the embryo, or a cluster of differently specified cells in a petri-dish
D. Cytoskeletal arrangements maintain positioning of nuclei in the syncytium, which enables specification of these nuclei by opposing morphogen gradients namely Bicoid and Caudal in Drosophila
E. Capacity for “mosaic" development allows cells to acquire different functions as a result of interactions with neighbouring cells.
Which of the above statements are correct?
QUESTION ID:19
A "morphogen” can determine the fate of a cell by its concentration. Given below are some statements on the experiment performed to study the gradient-dependent effect of the morphogen, activin on cell fate by placing activin (4 nm)-secreting beads on unspecified cells from an early Xenopus embryo:
A. Beads without activin did not elicit expression of either Xbra or goosecoid genes.
B. Cells nearest to the beads getting highest concentration of activin induced goosecoid gene whose product is a transcription factor, specifies the frog's dorsal-most structures.
C. Cells nearest to the beads getting highest concentration of activin induced Xbra gene whose product is a transcription factor, specifies the frog's dorsal-most structures.
D. Cells farthest from the beads getting negligible activing activate Xbra gene and become blood vessels and heart
E. Cells farthest from the beads getting negligible activin, activated neither Xbra nor goosecoid and the default gene expression instructed the cells to become blood vessels and heart. Which of the above observations and conclusions drawn are correct?
QUESTION ID:20
Following statements were made about the events occurring during chick development.
A. The fertilized chick egg undergoes discoidal meroblastic cleavage; however the cleavage does not extend into the yolk cytoplasm.
B. Development of primary hypoblast is mediated by localized migration of a group of highly specified and connected cluster of 30-40 cells.
C. By the stage XIII of chick embryogenesis and little prior to primitive streak formation, the formation of the hypoblast is just complete.
D. Hansen’s node of the chick embryo signifies a region at the anterior end of the primitive streak with regional thickening of cells.
E. Inhibition of Wnt planar cell polarity pathway in the epiblast causes the mesoderm and endoderm to form centrally instead of peripherally.
Which one of the following combinations represents all correct statements?
QUESTION ID:21
The following diagram represents a longitudinal section through an Arabidopsis shoot apical meristem (SAM) and leaf primordium at its flank. The dorsal (D) and ventral (V) domains are marked. The D and V genes are expressed in the dorsal and ventral domains, respectively.
Consider the following statements describing the phenotypes of leaf polarity.
A. Loss of D function makes the leaf ventralized whereas its overexpression dorsalizes the leaf.
B. Loss of V function makes the leaf dorsalized whereas its overexpression ventralizes the leaf.
C. Loss of microRNA miR166 dorsalizes the leaf whereas its overexpression ventralizes the leaf.
D. miR166 functions by inhibiting its target mRNA.
Which one of the following functional models best describes the above results?
QUESTION ID:22
During fertilization in mammals proteins Izumo and Juno are required for recognition of sperm and egg. Izumo and Juno are found specifically in sperm and egg, respectively. Which one of the following in vivo experiments will demonstrate that Izumo and Juno interact with each other?
QUESTION ID:23
Match the above columns involving plant hormones and their signalling pathways:
QUESTION ID:24
Which one of the following graphs best represents the net CO2 fixation of typical C3 and C4 plants under increasing CO2 concentration and saturating light?
QUESTION ID:25
Certain plant species produce cyanogenic glycosides to
protect them from pathogens. A researcher has identified a variant of such a
plant that has higher level of cyanogenic glycoside yet it is highly
susceptible to a specific fungal pathogen. To interpret this counter-intuitive
observation, the researcher hypothesizes that the fungal pathogen has higher
level of
B. formamide hydrolyase activity
QUESTION ID:26
The following statements were made with the assumption that
the concentration of 3 phosphoglycerate is high inside chloroplasts of an
actively photosynthesizing leaf.
QUESTION ID:27
A disease-resistant plant was crossed with a susceptible
plant and the resultant F1 plants were disease resistant. The F1 plant was
selfed and the F2 individuals were analysed for qualitative and quantitative
disease resistance. The following statements were hypothesized
QUESTION ID:28
A. Chlorophyll absorbs more in the red region of the visible
spectrum than in far-red.
QUESTION ID:29
Thyroid hormone (T3) increases the heart rate and the force
of contraction of cardiac muscles.
QUESTION ID:30
In the nervous system, the action potential is generated at the axon hillock in physiological conditions and it is conducted to the terminal end of axon. The location specific origin of action potential and its direction-specific conduction are explained by a researcher in the following proposed
statements:
A. The membrane of axon hillock has highest threshold for the generation of action potential
B. The membrane of axon hillock contains large numbers of voltage-gated Na+ channels and that makes it more excitable
C. The propagating action potential in the middle of the axon cannot generate another action potential in the direction of cell body since a large fraction of voltage-gated Na+ channels in the preceding portion is voltage inactivated
D. As the number of voltage-gated Na+ channels is less in the preceding portion of axonal membrane, the propagating action potential in the middle of the axon cannot generate another action potential in the direction of cell body.
Which one of the following combinations represents both correct explanations?
QUESTION ID:31
Aldosterone increases the reabsorption of Na+ From the
tubular fluid in the thick ascending limbof loop of Henle and in the distal
tubule. These effects are explained in the following proposed statements:
QUESTION ID:32
Hormone act by producing/activating a variety of effectors intracellularly. Below are given a variety of effectors in column 'X' and hormones in column 'Y
Which one of the following combinations of effector and the specific hormone is correct?
QUESTION ID:33
Drawn below is an intestinal epithelial cell (IEC) performing the absorption of digested monosaccharides from the dietary carbohydrates ingested?
Which one of the following combinations of the transporter (A, B and C in the figure above) and the transported monosaccharide is correct?
QUESTION ID:34
Individuals in a population are divided into various blood groups (in column 'X') based on the set of enzymes they have in column 'Y):
Which one of the following combinations is NOT correct for the blood group type and the set of enzymes a person has?
QUESTION ID:35
QUESTION ID:36
The individuals considered in this question are having two haploid sets of autosomes and no Y. chromosome. The X:A ratio of the individuals, the type of organisms chosen, their primary sex and number of Barr bodies expected in their cells are shown in the table below:
Select the option below with all correct matches:
QUESTION ID:37
In the following pedigree three STR loci A, B and C are linked on the long arm of the X-chromosome in the order centromere-A-B-C-telomere. Further in the table, the STR alleles present in each individual is indicated.
Based on the above, X-chromosome(s) in which of the following individuals are recombinant?
QUESTION ID:38
A. mt and ppt loci are on two different chromosomes
B. Inheritance of mating type and ppt- resistance/sensitivity are demonstrating cytoplasmic inheritance
C. Inheritance of kanamycin-resistance/sensitivity is demonstrating nuclear inheritance
D. Nuclear inheritance is being demonstrated by mating type and ppt-resistance/sensitivity analysis
Which one of the combinations of above statements is correct?
QUESTION ID:39
A pedigree shown below depicts that the individual I-1 is heterozygous for a dominant disease allele D and for molecular markers M1/M2. The paternal molecular markers present in the progeny individuals are indicated in the pedigree.
The following statements may be drawn from the above pedigree:
A. The two loci D/d and M1/M2 appears to be linked
B. The recombination frequency between the two loci is 20%
C. If LOD score comes out to be 3, then it ensures that the two loci are independently assorting
D. A LOD score <1 would have ensured that the two Loci are linked
Which combination of the above statements can correctly interpret the depicted pedigree?
QUESTION ID:40
An individual is having a paracentric inversion (denoted by the region f-e-d, marked by arrows) in homozygous condition.
The meiotic consequences of inversion can be:
A. generation of an acentric and a dicentric chromosome
B. the recombinants will have long deletion or duplication and may be lethal
C. the inversion will suppress crossing over
D. all gametes will have complete genome and will survive normally
Which of the above statement or their combinations will explain the meiotic consequence of the given inversion logically?
QUESTION ID:41
Following statements are made about double-strand break repair (DSBR) model of homologous recombination:
A Process of DSBR recombination is triggered by introducing a double-strand break in a DNA duplex
B. In a process known as 3-end resection, the exonucleases along with a DNA helicase degrade one strand on either side of the break and generates3'-single stranded termini
C. One strand of the donor duplex is displaced due to formation of heteroduplex DNA and generates a displacement loop (D-Loop)
D. Branch migration allows the point of crossover to move in 5'3' direction of recipient strand.
E. Completion of DSBR recombination may generate either crossover recombinant or non-recombinant product
Which one of the following combination of statements is correct?
QUESTION ID:42
Which of the following set of conditions will qualify a species to be considered as endangered (EN) as per IUCN criteria?
QUESTION ID:43
Given below are certain adaptations which are seen in various groups of anin
A. Ovipary
B. Streamlined body
C. Pouch for carrying eggs
D. Porous egg shell
E. Breast bone as large keel
F. Webbed feet
G. Laterally compressed coccygeal bone
H. Unidirectional pulmonary system to provide large quantities of oxygen
I. Barbules or hooklets on the vanes of each feather
Which combination of the above adaptations facilitate bird flight?
QUESTION ID:44
Match the following taxa with the genus of the microorganism
QUESTION ID:45
Match the following plant diseases with the name of pathogen associated with the disease
QUESTION ID:46
Which one of the following phylogenies best represents the evolutionary relationship among whales, dolphins, seals, deer and dogs?
QUESTION ID:47
The table below shows photosynthetic type,temperature and sunlight intensity levels.
Which of the following correctly matches the plant photosynthetic type with the temperature and sunlight conditions in which photosynthetic rate per unit leaf area is maximum for that plant?
QUESTION ID:48
Which of the following represents exponential growth in populations?
QUESTION ID:49
In the graph below, large boxes (denoted by P, Q, R,S) represent a region, whereas smaller boxes represent habitats. Labels S1, S2 above each small box represent species present in the given habitat denoted by that box.
Given the above graphs, choose the option which correctly depicts the regions which show maximum α and maximum β diversity, respectively
QUESTION ID:50
Which among the above sets of conditions are best suited for mimicry to be successful?
QUESTION ID:51
Which of the following is NOT a mechanism for species coexistence?
QUESTION ID:52
A small number (approximately 10) of mice are introduced
into an uninhabited island. Their population grows exponentially initially and
after 3 years, reaches a population size of 520 after
QUESTION ID:53
Area of patch 1 is 2000 m2 with a resource density of 5 units/m2 Area of patch 2 is 3000 m2 with a resource density of 10 units/m2. As per the theory of ideal-free distribution, organisms distribute themselves such that the expected ratio of abundance of organisms in the two patches (patch 1: patch 2) is
QUESTION ID:54
Match the geological time period with the extinction or diversification events associated with them:
QUESTION ID:55
Female fiddler crabs prefer male fiddler crabs with larger claws over males with smaller claws. If the selection pressure exerted is strong resulting in a skewed distribution of claw size, which of the following statements is true about the population's mean, median and mode?
QUESTION ID:56
The phylogeny below shows evolutionary relationships between 9 extant bird species and whether they display red or blue plumage.
Based on the above phylogeny and the distribution
QUESTION ID:57
The top panel (graphs a-c) represents trends of number of sperms produced per mating season with respect to number of mates, while the bottom panel (graphs i-iv) represents trends of time invested in paternal care with respect tto number of mates in birds.
Select the correct trend from each panel.
QUESTION ID:58
Given below are various types of molecular markers in Column A and properties of these markers in Column B.
Which one of the options given below correctly matches the molecular markers with theirproperties?
QUESTION ID:59
Several plants produce metabolites with important medicinal properties and have been extensively used in traditional medicine across the
world. Many of these compounds can now be purified or synthesized and are used in modern medicine. Given below is a list of metabolites, their plant source and medicinal use:
Which one of the following options is the most appropriate match of the compound with its plant source and use?
QUESTION ID:60
Given below are schematic representations of the T- DNA regions of four constructs that are to be used for Agrobacterium – mediated transformation to silence an endogenous plant gene represented as XYFP that is expressed constitutively in the plant.
M: Selectable marker gene expression cassette LB Left Border RB: Right Border
Which of the four constructs depicted above could be used to silence the target gene XYFP?
QUESTION ID:61
Given below are a few statements on use of plant breeding to
develop improved varieties of a crop plant
QUESTION ID:62
A mixed cell population was stained with two antibodies, one specific for cell surface antigen A and the other specific for cell surface antigen B. Anti-A antibody was labelled with fluorescein and anti-B antibody was labelled with Rhodamine. The cell population was then analysed for the presence of antigens by flow cytometry. Which one of the following is the correct outcome for this cell population?
QUESTION ID:63
The following statements are made regarding developing a
transgenic mouse:
QUESTION ID:64
The ECG recorded by different leads is analysed on the basis
of variation of electrical potential at various loci on the surface of the
body, and the time scale relation of different waves. After analysing the ECG,
following particulars of heart are proposed to be obtained
QUESTION ID:65
Given below are two sets of terms related to various methods used in biological science.
Which one of the following options correctly matches terms of Column A and Column B?
QUESTION ID:66
In an experiment, a 1 kb fragment with a single BamHI site (as shown below in figure "A") is to be cloned in the Smal (CCC ↓ GGG) site of a cloning vector of 3kb length (figure 'B'). None of the other enzymes of the multiple cloning sites are present in the fragment to be cloned.
Based on the information given above, a series of digestions were set up for the potential clones and their fragment profiles are given below:
A BamHI : 200bp + 3.8 kb
B. BamHI : 800bp + 3.2 kb
C. HindlIl + EcoRI : _1 kb +3kb
D. Xhol + BamHI : -200bp + -800bp + r-3kb
QUESTION ID:67
To investigate the dynamic nature of two unrelated centrosome-localized GFP-tagged proteins (GFP-A; GFP-B), a team of scientists conducted fluorescence recovery after photo bleaching (FRAP) experiment.
The FRAP profile of these two proteins is given below:
The following statements for this FRAP analysis were made
A. GFP-B shows faster exchange rate than GFP-A
B. GFP-A shows faster exchange rate than GFP-B
C. GFP-A has more immobile fraction than GFP-B
D. GFP-B has more immobile fraction than GFP-A
Which of the above mentioned statements for GFP-A and GFP-B are correct?
QUESTION ID:68
Absorption spectra of L-tyrosine in acidic (continuous line) and basic (dotted line) medium was estimated and plotted on a graph as depicted below:
Following interpretations were made:
A. Change in the pH from acidic to basic results in shift in the lowest energy absorption maximum and decrease in the molar absorptivity.
B. Shifting of the absorption band to longer wavelength signifies a shift to lower energy, also known as red shift
C. Shifting of the absorption band to shorter wavelength signifies a shift to higher energy, also known as blue shift.
D. Wavelength shift is always accompanied by change in intensity of the absorption band.
Select the combination with correct interpretations.