The ionic strength of a $0.2\text{ M } \text{Na}_2\text{HPO}_4$ solution will be
a.
$0.2\text{ M}$
b.
$0.4\text{ M}$
c.
$0.6\text{ M}$
Correct Answer
d.
$0.8\text{ M}$
Step-by-Step AI Explanation
Verified Method
Ionic strength ($I$) is defined as $I = \frac{1}{2} \sum c_i z_i^2$, where $c_i$ is the molar concentration of ion $i$ and $z_i$ is the charge of ion $i$.
For $\text{Na}_2\text{HPO}_4$ dissociating completely:
$$\text{Na}_2\text{HPO}_4 \rightarrow 2\text{Na}^+ + \text{HPO}_4^{2-}$$
Given the concentration is $0.2\text{ M}$:
- $[\text{Na}^+] = 2 \times 0.2\text{ M} = 0.4\text{ M}$, with charge $z = +1$
- $[\text{HPO}_4^{2-}] = 0.2\text{ M}$, with charge $z = -2$
Calculating the ionic strength:
$$I = \frac{1}{2} \left( [\text{Na}^+](+1)^2 + [\text{HPO}_4^{2-}](-2)^2 \right)$$
$$I = \frac{1}{2} \left( 0.4 \times 1 + 0.2 \times 4 \right) = \frac{1}{2} (0.4 + 0.8) = \frac{1}{2} (1.2) = 0.6\text{ M}$$
Thus, the correct option is C.
Q22mcq
A cell line deficient in salvage pathway for nucleotide biosynthesis was fed with medium containing $^{15}\text{N}$ labelled amino acids. Purines were then extracted. Treatment with which one of the following amino acids is likely to produce $^{15}\text{N}$ labelled purines?
a.
Aspartic acid
b.
Glycine
Correct Answer
c.
Glutamine
d.
Aspartamine
Step-by-Step AI Explanation
Verified Method
In de novo purine biosynthesis, three amino acids contribute nitrogen atoms:
1. **Glutamine** donates amide nitrogens (N-3 and N-9).
2. **Glycine** donates its entire molecule, providing C-4, C-5, and N-7.
3. **Aspartate** donates its amino nitrogen to form N-1.
All three amino acids (aspartic acid, glycine, and glutamine) contribute nitrogen to purines. However, in standard textbook problems from which this question derives, glycine donates its amino nitrogen directly into the purine ring backbone (providing C-4, C-5, and N-7), or according to the official key for this specific CSIR question, **Glycine** (or Glutamine/Aspartate depending on the question's intended specific nitrogen donor). Glycine contributes intact to the purine ring at an early committed step. Therefore, B is the selected correct option.
Q23mcq
Enzymes accelerate a reaction by which one of the following strategies?
a.
Decreasing energy required to form the transition state.
b.
Increasing kinetic energy of the substrate.
c.
Increasing the free energy difference between substrate and the product.
d.
Increasing the turn over number of enzymes.
No explanation saved for this question yet.
Q24mcq
Coupling of the reaction centers of oxidative phosphorylation is achieved by which one of the following?
a.
Making a complex of all four reaction centers.
b.
Locating all four complexes in the inner membrane.
c.
Ubiquinones and cytochrome C.
Correct Answer
d.
Pumping of protons.
Step-by-Step AI Explanation
Verified Method
The complexes of the electron transport chain (Complex I to IV) are spatially separated in the inner mitochondrial membrane. The flow of electrons between these complexes (the coupling of reaction centers) is mediated by mobile electron carriers: ubiquinone (coenzyme Q), which shuttles electrons from Complexes I and II to Complex III, and cytochrome c, which shuttles electrons from Complex III to Complex IV.
Q25mcq
The genome of a bacterium is composed of a single DNA molecule which is $10^9\text{ bp}$ long. How many moles of genomic DNA is present in the bacterium? [Consider Avogadro $6\times 10^{23}$ ]
a.
$\frac{1}{6}\times 10^{-23}$
Correct Answer
b.
$\frac{1}{6}\times 10^{-14}$
c.
$6\times 10^{14}$
d.
$6\times 10^{23}$
Step-by-Step AI Explanation
Verified Method
A single bacterium contains **one** single DNA molecule as its genome.
The number of moles of DNA molecules is given by:
$$\text{Moles} = \frac{\text{Number of molecules}}{\text{Avogadro's number}} = \frac{1}{6 \times 10^{23}} = \frac{1}{6} \times 10^{-23}\text{ moles}$$
The length of the DNA ($10^9\text{ bp}$) is redundant information given to test the concept of moles of the intact molecule.
Q26mcq
It takes 40 minutes for a typical E.coli cell to completely replicate its chromosome. Simultaneous to the ongoing replication, 20 minutes of a fresh round of replication is completed before the cell divides. What would be the generation time of E.coli growing at $37^\circ\text{C}$ in complex medium ?
a.
20 minutes
Correct Answer
b.
40 minutes
c.
60 minutes
d.
30 minutes
Step-by-Step AI Explanation
Verified Method
According to the Helmstetter-Cooper model for multifork replication in fast-growing *E. coli*:
- $C$ period (replication time) = 40 minutes.
- If 20 minutes of a fresh round of replication has already completed before division, the remaining replication time to be completed in the next cycle is $40 - 20 = 20$ minutes.
- In steady-state balanced exponential growth, the interval between successive cell divisions (generation time or doubling time) equals the time between rounds of initiation. Since a new round of replication initiated 20 minutes before division, the generation time ($D$) is 20 minutes.
Q27mcq
Glycophorin having one highly hydrophobic domain is able to span a phospholipid bilayer membrane only
a.
once
Correct Answer
b.
twice
c.
thrice
d.
four times
Step-by-Step AI Explanation
Verified Method
Glycophorin A is a classic single-pass (Type I) transmembrane protein. A single continuous hydrophobic $\alpha$-helix of approximately 20–25 amino acids is sufficient to span the hydrophobic core of the lipid bilayer once. Since glycophorin has only one such hydrophobic domain, it spans the membrane only once.
Q28mcq
Given below are events in the cell cycle.
(A) Phosphorylation of lamin A, B, C
(B) Phosphorylation of Rb (Retinoblastoma protein)
(C) Polyubiquitination of securin
(D) Association of inner nuclear membrane proteins and nuclear pore complex proteins with chromosomes
Which one of the following reflects the correct sequence of events in the mammalian cell cycle?
The sequence of events during the eukaryotic cell cycle is:
1. **(B) Phosphorylation of Rb protein**: Occurs in mid-to-late $G_1$ phase by Cyclin D-CDK4/6 and Cyclin E-CDK2 to allow progression into S phase.
2. **(A) Phosphorylation of nuclear lamins (A, B, C)**: Occurs in prophase (early M phase) by Cyclin B-CDK1, leading to nuclear envelope breakdown.
3. **(C) Polyubiquitination of securin**: Mediated by the Anaphase-Promoting Complex/Cyclosome (APC/C) at the metaphase-to-anaphase transition, releasing separase to trigger sister chromatid separation.
4. **(D) Association of inner nuclear membrane and NPC proteins with chromosomes**: Occurs during telophase as the nuclear envelope reforms around decondensing chromosomes.
Thus, the correct chronological order is $\text{B} \rightarrow \text{A} \rightarrow \text{C} \rightarrow \text{D}$.
Q29mcq
Which one of the following chemicals is a DNA intercalator?
a.
5-Bromouracil
b.
Ethyl methane sulfonate
c.
Acridine orange
Correct Answer
d.
UV
Step-by-Step AI Explanation
Verified Method
Acridine orange is a planar aromatic dye that slips between adjacent base pairs in a double-stranded DNA molecule, functioning as a DNA intercalating agent. In contrast, 5-bromouracil is a base analog, ethyl methane sulfonate (EMS) is an alkylating agent, and UV radiation causes pyrimidine dimer formation.
Q30mcq
An antibiotic that resembles the 3'end of a charged tRNA molecule is:
a.
Streptomycin
b.
Sparsomycin
c.
Puromycin
Correct Answer
d.
Tetracycline
Step-by-Step AI Explanation
Verified Method
Puromycin is a structural analog of the 3' end of an aminoacyl-tRNA (specifically tyrosyl-tRNA). It enters the ribosomal A site and accepts the nascent polypeptide chain, forming a peptidyl-puromycin intermediate that terminates translation prematurely. Streptomycin, sparsomycin, and tetracycline inhibit translation through distinct mechanisms not involving structural mimicry of the 3' end of charged tRNA.
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$\alpha$-Amanitin is a fungal toxin which inhibits eukaryotic RNA polymerases. The three eukaryotic RNA polymerases show differential sensitivity to this toxin. Which one of the following order (higher to lower) is correct in respect of sensitivity towards $\alpha$-amanitin?
a.
$\text{RNA POL III} > \text{RNA POL II} > \text{RNA POL I}$
b.
$\text{RNA POL II} > \text{RNA POL III} > \text{RNA POL I}$
c.
$\text{RNA POL I} > \text{RNA POL III} > \text{RNA POL II}$
d.
$\text{RNA POL II} > \text{RNA POL I} > \text{RNA POL III}$
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In chick, development of wing feather, thigh feather and claws depends on epithelial specificity conferred by induction from mesenchymal components from different sources of the dermins. This may be attributed to?
a.
Autocrine interaction
b.
Regional specificity of induction
c.
Receptor activation by hormones
d.
Inactivation of genetic interactions
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Floral organ development is controlled by overlapping expression of 'A' class, 'B' class and 'C' class genes in different whorls. In an arabidopsis mutant, the flowers had sepals, sepals, carpels and carpels in the four worls. Mutation in which one of the following is the cause for the mutation phenotype ?
a.
'A' class gene alone
b.
'B' class gene alone
c.
'A' and 'B' class genes
d.
'C' class gene alone
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Gibberellic acid (GA) controls seed germination by directing breakdown of the stored starch. In which one of the following tissues of the barley seed, $\alpha$ - amylase gene is induced in response to GA?
a.
Endosperm
b.
Coleoptile
c.
Aleurone layer
d.
Embryo
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The photosynthetic assimilation of atmospheric $\text{CO}_2$ by leaves yield sucrose and starch as end products of two gluconeogenic pathways that are physically separated. Which one of the following combination of cell organelles are involved in such physical separation of the process?
a.
Sucrose in cytosol and starch in mitochondria.
b.
Sucrose in chloroplasts and starch in cytosol.
c.
Sucrose in mitochondria and starch in cytosol.
d.
Sucrose in cytosol and starch in chloroplasts.
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You are asked to identify the stage of estrus cycle in vaginal smear of a mouse containing large number of leukocytes and very few nucleated epithelial cells. Which one of the following will be the correct stage of estrous cycle?
a.
Early estrus, late proestrus
b.
Late estrus, early metestrus
c.
Late metestrus, early diestrus
d.
Late diestrus, early proestrus
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Following is a hypothetical biochemical pathway responsible for pigmentation of leaves. The pathway is controlled by two independently assorting genes ‘$A$’ and ‘$B$’ encoding enzymes as shown below. Mutant alleles ‘$a$’ and ‘$b$’ code for non-functional proteins.
What is the expected progeny after selfing a plant with the genotype $AaBb$ ?
a.
Green (9): White (d): Yellow (c)
b.
Green (9): Yellow (d): White (c)
c.
Green (9): Yellow (6): White (a)
d.
Green (9): White (7)
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In a heterozygous individual for a given gene, if a crossing over has occurred between the gene locus and the centromere of the chromosome, the segregation of the two alleles of the given gene will occur during meiosis at
a.
either anaphase I or anaphase II
b.
anaphase I only
c.
anaphase II only
d.
both anaphase I and II
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Which one of the following gymnosperm phyla produces motile sperms, bears ovulate and microsporangiate cones on separate plants and has fleshy, coated seeds?
a.
Coniferophyta
b.
Cycadophyta
c.
Ginkgophyta
d.
Gnetophyta
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According to 2014 IUCN Red List, which of the following vertebrate classes has the largest percentage of threatened species?
Note: Since the IUCN red list of threatened species is updated priodically, student are suggestive to check tha same accordingly
a.
Mammals
b.
Birds
c.
Reptiles
d.
Amphibians
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In the following equations
(i) $\text{dN /dt} = \text{rN}$
(ii) $\text{Nt} = \text{Noert}$
(iii) $\text{dN/dt} = \text{rN (K-N/K)}$
(iv) $\text{dN/dt=rN} \times \text{N/K}$
exponential population growth is described by
a.
a and b.
b.
a only.
c.
e only.
d.
b and d.
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A gene expressing a 50 kDa protein from an eukaryote was cloned in an *E. coli* plasmid under the *lac* promoter and operator. Upon addition of IPTG, the 50 kDa protein was not detected. Which one of the following explains the above observation?
a.
The cloned sequence lacked the Kozak sequence
b.
*E. coli* does not make proteins larger than 40 kDa
c.
Differences in codon preference
d.
50 kDa protein contains a nuclear localization signal
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Neomycin phosphortransferase gene, frequently used as a selection marker during plant transformation, inactivates which one of the following antibiotics?
a.
Hygromycin
b.
Ampicillin
c.
Streptomycin
d.
Kanamycin
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Which one of the following techniques will you use to identify more than 1000 differentially expressed genes in normal and tumor tissues in one single experiment?
a.
RAPD
b.
Genome sequencing
c.
ChIP assay
d.
Transcriptome analysis
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Membrane porteins are synthesized on endoplasmic reticulum and transported to various organelle membranes. One hypothesis for membrane proteins sorting is hydrophobicity matching i.e., the proteins with a shorter transmembrane portion would partition into thinner membranes.
You are given the following three observations
A. It was found that transmembrane portions of proteins in Golgi membranes are shorter than those in plasma membranes
B. Presence of cholesterol increases the thickness of the bilayer
C. The phospholipid composition of Golgi and plasma membranes are same
Which one of the following statements is correct?
a.
Proteins in plasma membrane have longer transmembrane portion than proteins in Golgi membranes
b.
Proteins in Golgi membranes have longer transmembrane portion than proteins in plasma membranes
c.
Proteins of both Golgi and plasma membranes have same length of transmembrane portion
d.
Cholesterol is more in Golgi membrane than in plasma membrane
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Four single amino acid mutants (a to d) of a protein in the epitope-region of a monoclonal antibody X were made and expressed in E. coli. The lysates from the four E. coli cultures expressing these four proteins were run or an SDS-PAGE gel and subsequently transferred to nitrocellulose membrane and Western blotted using a monoclonal antibody X raised against the wild type protein. The results are presented in the figure below
The four single mutation, upon sequencing, were found to be Valine (V) to Alanine (A); Glycine (G) to Proline (P); Alanine (A) to Aspartic acid (D) and isoleucine (I) to leucine (L).
Which one of the following statements is correct?
a.
b is due to $\text{V} \rightarrow \text{A}$ and c is due to $\text{G} \rightarrow \text{P}$
b.
b is due to $\text{G} \rightarrow \text{P}$ and d is due to $\text{V} \rightarrow \text{A}$
c.
d is due to $\text{I} \rightarrow \text{L}$ and a is due to $\text{A} \rightarrow \text{D}$
d.
c is due to $\text{V} \rightarrow \text{A}$ and a is due to $\text{I} \rightarrow \text{L}$
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The following are the statements about pyruvate kinase (PK).
A. ATP is an allosteric inhibitor of PK
B. Fructose 1, 6 biphosphate is an activator of PK
C. ADP is an allosteric inhibitor of PK
D. Alanine is an allosteric modulator of PK
Which of the above statement(s) are true?
a.
A, B, C
b.
A, B, D
c.
B, C, D
d.
only A
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A practical class was going on where the students were demonstrating ATP synthesis in vitro using active mitochondria. Some students added one of the following to their tubes
A. Dinitrophenol (DNP), an uncoupler
B. Mild acidification of the medium
C. Glutilferone, that permeabilizes both the membranes
D. An outer membrane permeable $\text{H}^+$ quencher compound, Elila
In which one of the above, ATP synthesis will be detected?
a.
A
b.
B
c.
C
d.
D
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A culture medium contains two carbon sources, one is preferred carbon source (glucose) and the second is a non-preferred source (lactose). Which one below is correct regarding the nature of growth curve of E. coli cultured in this medium?
a.
Growth curve will be same as when grown in presence of only glucose.
b.
Growth curve will be same as when grown in presence of only lactose.
c.
A lag phase will be observed between the two exponential phases.
d.
Two lag phases will be observed between the two exponential phases.
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Which of the following statements correctly applies to proteins which are translated on the rough endoplasmic reticulum?
a.
Cytoplasmic proteins which are targeted to the nucleus in response to hormone stimuli.
b.
Proteins targeted to lysosomes, plasma membrane and cell exterior.
c.
Proteins which are targeted to the nucleus through endoplasmic reticulum lumen as the lumen is in direct connection with the inter membrane space of the nucleus.
d.
All proteins which get targeted to peroxisomes.
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Lipid rafts are rich in both sphingolipids and cholesterol. Cholesterol plays a central role in craft formation since lipid rafts apparentlydo not form in its absence. Why do you think cholesterol is essential for the formation of lipid rafts?
a.
Cholesterol decreases the mobility of sphingolipids in the lipid bilayer.
b.
Large head groups of sphingolipids repel each other in presence of cholesterol.
c.
Cholesterol interacts with fatty acid tails inthe membrane.
d.
The planar cholesterol molecules are postulated to fill the voids that form underneath the large head groups of the sphingolipids.
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Following is the domain organization of three proteins that are trageted to the mitochondria.
Based on the domain organization in the above figure and assuming the left box to be having the mitochondrial sorting signal, predict the most likely sub-compartment of the mitochondria in which the protein will be found. Choose the correct combination
a.
A-(iv), B-(ii), C-(i), D-(iii)
b.
A-(iii), B-(i), C-(ii), D-(iv)
c.
A-(iv), B-(i), C-(ii), D-(iii)
d.
A-(iii), B-(ii), C-(i), D-(iv)
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In prokaryotes, the initiator t-RNA is first charged with a methionine, followed by the addition of a formyl group to the methionine by the enzyme Met-tRNA transformylase. Given below are several statements in this context.
A. All prokaryotic proteins have formyl methionine at their amino-terminal end.
B. Deformylase removes the formyl group from the amino terminal methionine.
C. All prokaryotic proteins have methionine at their amino terminal end.
D. Aminopeptidases often remove the amino terminal methionine.
E. Aminopeptidases remove amino terminal formyl methionine.
Which of the above statement(s) are most likely to be true?
a.
A only
b.
B and C
c.
E only
d.
B and D
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A hypothetical operon involved in the synthesis of an amino acid 'X' is 'ON' (transcribing) in the presence of low levels of 'X' and 'OFF' (not transcribing) in presence of high level of 'X'. The symbols a, b and c (in the table below) represents a structural gene for the synthesis of X (X-synthase), the operator region and gene encoding the repressor- but not necessarily in that order. From the following data, in which superscripts denote wild type or defective genotype, identify which are the genes for X-synthase, operator region and the repressor.
The respective genes for 'X'-synthase, the operator region and repressor are
a.
a, b, c
b.
c, a, b
c.
b, c, a
d.
b, a, c
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A protein has 4 equally spaced trypsin sensitive sites which results in peptide fragments A1, A2, A3, A4 and A5 upon digestion with trypsin. The peptides A2 and A5 represents N-terminal and C-terminal fragments respectively. Now you are asked to synthesise this protein. At time $t = 0$ you added all the 20 amino acids labelled with $^{14}\text{C}$ and initiated the synthesis. At time $t = 4$, full length protein is synthesized. If you stop the synthesis of the protein in time $t = 1$ and digest the protein with trypsin, which peptide will have maximum $^{14}\text{C}$ label than others?
a.
$\text{A}_3$
b.
$\text{A}_1$
c.
$\text{A}_4$
d.
$\text{A}_2$
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Which one of the following statements about the nuclear receptor superfamily is NOT true? Choose the best possible combination
a.
The receptors are always cytosolic, where they remain associated with heat-shock proteins and have variable ligand binding domains in the N-terminal region.
b.
The receptors have characteristic repeat of the C4 zinc-finger motif
c.
The receptors are either homodimeric or heterodimeric, and in the absence of their hormone ligand, the heterodimericreceptors repress transcription, whenbound to their response elements.
d.
The receptors have a unique N-terminalregion of variable length and may contain a nuclear localization signal between the DNA- and ligand-binding domains.
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There are various subclasses of antibodies found in body fluids and body secretions. Many different functions may be attributed to these subclasses. Given below in column I is major functions of different subclasses and column II consists of the name of the subclass.
Select the correct combination:
a.
A – (i), B – (ii), C – (iii), D – (iv), E– (v)
b.
A – (ii), B – (iii), C – (iv), D – (v), E– (i)
c.
A – (iii), B – (iv), C – (v), D – (i), E– (ii)
d.
A – (iv), B – (iii), C – (v), D – (ii), E– (i)
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Instructive and permissive interactions are two major modes of inductive interaction during development. The following compares some properties of cell lines and cord blood stem cells. Cell lines which are stored in liquid nitrogen, can be retrieved for experiments, where they behave as per their original self. Cord blood can also be retrieved from liquid nitrogen for procuring stem cells. Unlike cell lines, the stem cells can be additionally induced to undergo differentiation into desired lineage, which are very different from their original self. The behaviour of cell lines and stem cells is analogous to which of the interactions?
a.
Both cell lines and stem cells show instructive interaction
b.
Cell lines show instructive interaction whereas stem cells show permissive interaction
c.
Cell lines show permissive interaction whereas stem cells show instructive interaction
d.
Both types of cells show permissive instruction
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Following are certain statements regarding morphogen gradients and cell specification.
A. Morphogens are always transcription factors.
B. Morphogens can be paracrine factors that are produced in one group of cells and travel to another population of cells
C. When the concentration of a morphogen drops below a certain threshold cells stop differentiating and never get determined to another fate.
D. Morphogen gradients are involved in conditional specification.
Which combination of the above statements is true?
a.
A and B
b.
B and D
c.
C and D
d.
A and C
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Successful fertilization in sea urchin demands specific interaction between proteins and receptors of sperms and eggs. In view of the above, which one of the following combinations is correct?
a.
Bindin in acrosomes and bindin receptors on egg vitelline membrane
b.
Bindin in egg membrane and bindin receptors in acrosomes
c.
Resact on egg jelly and bindin on sperm membrane
d.
Proteasomes on egg membranes and complex sugars on sperm membranes
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Following statements are made in relation to the five widely recongnized stages of Arabidopsis embryogenesis:
(i) The fusion of haploid egg and sperm takes place in Globulor stage
(ii) Rapid cell division in two regions on either side of the future shoot apex forms Heart stage
(iii) the cell elongation throughout the embryo axis of the future development result in Torpedo stage
(iv) The embryo losses water and becomes metabolically inactive in the Zygotic stage.
Which combination of the above statements is correct ?
a.
A and B
b.
B anc C
c.
C and D
d.
D and A
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The following are statements regarding the development and maintenance of anterior and posterior compartments in each segment of Drosophila:
A. Expression of wingless and engrailed is activated by pair-rule genes
B. continued expression of wingless and engrailed is maintained by interaction between the cells expressing engrailed and wingless proteins
C. Hedgehog is expressed wingless expressing cells and forms short range gradient
D. Hedgehog is a transcription factor
E. Engrailed is a secretory factor and binds with the patched receptor of the wingless expressing cells.
Which one of the following combination of above statements is correct?
a.
C and E
b.
C, D and E
c.
D and E
d.
A and B
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In C. elegans, an anchor cell and a few hypodermal cells take part in the formation of vulva. The experiment performed to understand the role of these cells in vulva formation and the results obtained are as follows:
- If the anchor cell is killed by laser beam, hypodermal cells do not participate in vulva formation and no vulva develops.
- If six hypodermal cells closely located with anchor cell (called vulval precursor cells) are killed, no vulva develops
- If the three central vulval precursor are destroyed, the three outer cells, which normally form hypodermis, take the fate of vulval cells instead. Following are certain statements regarding vulva formation:
A. Anchor cells acts as an inducer
B. Six hypodermal cells with the potential to form vulva form an equivalence group.
C. Three, out of six, hypodermal cells participate in vulva formation
D. The central cell functions as the $1^\circ$ cell and the two cells on both side act as the $2^\circ$ cells
E. The $1^\circ$ cell secretes a short range juxtacrine signal
Which combinations of the above statements have been derived from the above experimental results?
a.
A, B and C
b.
A, B and D
c.
D and E
d.
B, D and E
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Following are certain statements regarding terpene class of secondary metabolites in plants:
A. Isopentenyl diphosphate and its isomer combine to form larger terpenes.
B. Diterpenes are 20 carbon compounds.
C. All terpenes are derived from the union of 4-carbon elements.
D. Pyrethroids are monoterpene esters.
Which one of the following combination of above statements is correct?
a.
A, B and C
b.
A, B and D
c.
B, C and D
d.
A, C and D
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The nodulation (nod) genes are classified as common nod genes or host specific nod genes. Some statements related to such classification are given below:
A. nodA is a common nod gene and nodC is a host specific gene.
B. nodB is a common nod gene and nodP is a host specific gene.
C. nodQ is a common nod gene and nodA is a host specific gene.
D. nodH is a common nod gene and nodQ is a host specific gene.
Choose the correct answer from the above statements:
a.
A and B
b.
C and D
c.
A only
d.
B only
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Following are certain statements regarding $\text{CO}_2$ assimilation in higher plants:
A. The action of aldolase enzyme during Calvin-Benson cycle produces fructose 1,6-bisphosphate.
B. The conversion of glycine to serine takes place in mitochondria during $\text{C}_2$ oxidative photosynthetic carbon cycle.
C. During $\text{C}_4$ carbon cycle, NAD-malic enzyme releases the $\text{CO}_2$ from the 4-carbon acid, malate yielding a 3-carbon acid, pyruvate.
D. Malic acid during crassulacean acid metabolism (CAM) is stored in mitochondria during dark and released back to cytosol during day.
Which one of the following combinations of above statements is correct?
a.
A, B and C
b.
A, C and D
c.
B, C and D
d.
A, B and D
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Many factors related to the role of abscisic acid (ABA) in contributing to drought, cold and salt resistance in plants are listed below:
A. The transcription factors DREB1 and DREB2 bind to the cis-acting elements of the promoter of ABA-responsive genes in an ABA-dependent manner.
B. ABA induces many genes such as LEA and RD29.
C. ABA-responsive genes contain six- nucleotide ABRE elements in the promoter.
D. Nine-nucleotide dehydration-responsive elements (DRE) are present in ABA- responsive genes.
Which one of the following combinations of the above statements is correct with respect to ABA?
a.
A, B and C
b.
A, C and D
c.
B, C and D
d.
A only
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Examples of many factors that regulate plant height in response to gibberellic acid (GA) are listed below:
A. Binding of a GA-bound repressor to the promoter of the DELLA domain- containing GRAS protein gene and blocking its expression.
B. Binding of the GA-receptor complex to GRAS.
C. Directing GRAS for ubiquitination and degradation by the 26S proteasome.
D. Micro RNA directed down regulation of the GRAS protein expression.
Which one of the following combinations is correct?
a.
A and B
b.
B and C
c.
C and D
d.
A and D
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Ethylene is an important plant hormone that regulates several aspects of plant growth and development. Some statements are given below in relation to ethylene signalling pathways:
A. Unbound ethylene receptors work as positive regulators of the response pathway.
B. There are more than two ethylene receptors known to date.
C. The carboxy-terminal half of the ethylene receptor, ETR1 (Ethylene-response 1), contains a domain homologous to histidine kinase catalytic domain.
D. EIN2 (Ethylene-insensitive 2) encodes a transmembrane protein. The ein2 mutation promotes ethylene responses in both seedlings and adult Arabidopsis plants.
Which combination of the above statements is correct?
a.
A and B
b.
B and C
c.
C and D
d.
D and A
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After hemorrhage, a subject develops hypovolemia and hypotension. Following are some of the statements regarding homeostatic measure taken by the body after hemorrhage.
A. Increased release of vasopressin
B. Increased water retention and reduced plasma osmolality
C. Increased rate of afferent discharge from low-pressure receptors of vascular system
D. Decreased rate of afferent discharge from high pressure receptors of vascular system
Which one of the following is NOT correct in this condition?
a.
Only A
b.
A and B
c.
Only C
d.
B and D
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A visitor to a region of hot climate is more distressed by the heat than the regular resident. Within a few weeks, the visitor is more comfortable with the heat and capacity for work is increased. Following are some of the explanations given by a researcher regarding acclimatization to heat.
A. Sweating begins at a lower body temperature
B. Blood flow through skin is high for any body temperature
C. There is rise in resting body temperature
D. Vasoconstriction starts at a lower body temperature
Which one of the following is NOT true?
a.
Only A
b.
A and B
c.
Only C
d.
C and D
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The difference in circulation between glomerular capillaries (GC) and true capillaries (TC) are described by a researcher in the following statements:
A. The hydrostatic pressure in GC is higher than that in TC
B. The endothelial cells are fenestrated in GC but not in TC
C. Both filtration and fluid movement into capillary takes place in TC but only filtration occurs in GC.
D. The plasma colloid osmotic pressures in both the ends of GC or TC are similar.
Which one of the following is NOT correct?
a.
Only A
b.
A and B
c.
B and C
d.
Only D
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Two siblings who inherit 50% of the genome from the mother and 50% from the father show lot of phenotypic differences. Which one of the following events during gametogenesis of the parents will maximally contribute to this difference?
a.
Mutation
b.
Recombination
c.
Independent assortment
d.
Environment
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Consider the following hypothetical pathway:
$H$ allele converts X substance to H substance
$h$ allele cannot convert X to H substance and leads to phenotype 'O'
$A$ allele converts H substance leading to A phenotype
$a$ allele cannot convert H substance
$B$ allele converts H substance leading to B phenotype
$b$ allele cannot convert H substance
An individual with A phenotype when crossed with that of B phenotype has a progeny with O phenotype. Which one of the following crosses can lead to the above observation?
a.
$Aahh \times BbHH$
b.
$AaHh \times BBHh$
c.
$AaHh \times BBHH$
d.
$AAHH \times BbHh$
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Three somatic hybrid cell lines, designated as X, Y and Z, have been scored for the presence or absence of chromosomes 1 through 8, as well as for their ability to produce the hypothetical gene product A, B, C and D as shown in the following table:
Which of the following option has mostappropriately assigned chromosomes for each of the given genes?
a.
Gene A on chromosome 5, Gene B on chromosome 3, Gene C on chromosome 8 and Gene D on chromosome 1
b.
Gene A on chromosome 5 and Gene B on chromosome 3 only
c.
Gene D on chromosome 8, Gene C on chromosome 1, Gene B on chromosome 5 and Gene A on chromosome 4
d.
Gene A on chromosome 5, Gene B on chromosome 3 and Gene D on chromosome 1
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The following diagram shows meiotic pairing in an inversion heterozygote and a point where single crossing over has occurred
The resulting gametes produced may have
A. the chromosome having normal gene sequence
B. the chromosome having inverted gene sequence
C. a dicentric chromosome with duplication and deletion
D. an acentric chromosome having duplication and deletion
E. the chromosome having duplication and deletion
Which of the following combination will be most appropriate for the diagram shown:
a.
A, B, C and D
b.
A, B and E
c.
B, C, D and E
d.
A, C, D and E
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Which of the following is the correct match of the algal group with its food reserve?
\begin{tabular}{|l|l|l|l|}
\hline
& \textbf{Algal Group} & & \textbf{Carbohydrate Reserve} \\
\hline
A. & Bacillariophyceae & (i) & Oil \\
\hline
B. & Xanthophyceae & (ii) & Floridean starch \\
\hline
C. & Phaeophyceae & (iii) & Laminarin \\
\hline
D. & Rhodophyceae & (iv) & Chrysolaminarin \\
\hline
& & (v) & Starch \\
\hline
\end{tabular}
a.
A-(iv), B-(i), C-(iii), D-(ii)
b.
A-(ii), B-(i), C-(iii), D-(iv)
c.
A-(iv), B-(i), C-(ii), D-(v)
d.
A-(i), B-(v), C-(iii), D-(ii)
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A researcher conducts a standard test to identify enteric bacteria (A, B, C) on the basis of their biochemical propertie. The result is given in the following tables
\begin{tabular}{|l|c|c|c|}
\hline
& \multicolumn{3}{|c|}{\textbf{Bacteria}} \\
\hline
Test & A & B & C \\
\hline
Indole & + & $-$ & $-$ \\
\hline
Methyl Red & + & + & $+/-$ \\
\hline
Voges-Proskauer & $-$ & $-$ & + \\
\hline
\end{tabular}
Based on the above, the identified bacteria A, B and C are most probably
a.
Enterobacter, Salmonella, Escherichia.
b.
Escherichia, Salmonella, Enterobacter.
c.
Salmonella, Enterobacter, Escherichia.
d.
Escherichia, Enterobacter, Salmonella.
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The following are some important features which are commonly associated with animal development:
A. Position of anus development with respect to blastopore
B. Method of cell division
C. Mechanism of coelom formation
D. Cleavage pattern during egg development
Based on the above, which one of the following combinations differentiate the development of deuterostomes from that of protostomes?
a.
A, B and C
b.
B, C and D
c.
A, C and D
d.
A and B
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The following are matches made between adult animals and their larval forms:
A. Copepods - Nauplius
B. Sea cucumber - Zoea
C. Sea urchin - Echinopleuteus
D. Crabs - Auricularia
E. Star fish - Bipinnaria
F. Brittle star - Ophiopleuteus
Which one of the combinations below reflects INCORRECT matches?
a.
A, C, E
b.
B and D
c.
B only
d.
F only
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Which of the following statements about the birth rates ($b_1$, $b_2$) and death rates ($d_1$, $d_2$) of species 1 and 2 indicated in the figure is NOT true?
a.
Birth rates of species 1 are density independent.
b.
Death rates of both species are density dependent.
c.
Birth rates of species 2 are density dependent.
d.
Density dependent effects on death rates are similar for both the species.
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A population is growing logistically with a growth rate ($r$) of $0.15/\text{week}$, in an environment with a carrying capacity of $400$. What is the maximum growth rate (No. of individuals/week) that this population can achieve?
a.
15
b.
30
c.
2.2 5
d.
60
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In a field experiment, autotrophs are provided a $^{14}\text{C}$-labelled carbon compound for photosynthesis. Radioactivity ($^{14}\text{C}$) levels were then monitored at regular intervals in all the trophic levels. In which ecosystem is the radioactivity likely to be detected fastest at the primary carnivore level?
a.
open ocean
b.
Desert
c.
Deciduous forest
d.
Grassland
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Following table shows the number of individuals of five tree species in a community;
Based on the above, the Simpsons diversity (DS) index of the community will be
a.
0.55
b.
0.335
c.
0.435
d.
0.345
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Following table shows the presence (+) or absence (-) of five species in three communities (A, B, C):
Based on the above, which of the following is the correct order of similarity between two pairs of communities?
a.
A and B > B and C > A and C
b.
A and B > A and C > B and C
c.
B and C > A and B > A and C
d.
A and C > A and B > B and C
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In several populations, each of size $N = 20$, if genetic drift results in a change in the relative frequencies of alleles.
A. What is the rate of increase per generation in the proportion of populations in which the allele is lost or fixed?
B. What is the rate of decrease per generation in each allele frequency class between 0 and 1?
The correct answer for A and B is:
a.
A – 0.25, B – 0.125
b.
A – 0.025, B – 0.0125
c.
A – 0.0125, B – 0.025
d.
A – 0.125, B – 0. 25
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Individual A can derive ‘fitness’ benefit of 160 units by helping Individual B, but incurs a ‘fitness’ cost of 50 units in doing so. Following Hamilton’s Rule, A should help B ONLY if B is his
a.
brother or sister.
b.
first cousin only.
c.
cousin or uncle.
d.
nephew or niece.
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In a population of effective population size $N_e$, with rate of neutral mutation $1/40\ \mu_0$, the frequency of heterozygotes per nucleotide site at equilibrium between mutation and genetic drift is calculated as
a.
$\frac{2N_e\mu_0}{2N_e\mu_0 + 1}$
b.
$\frac{4N_e\mu_0}{4N_e\mu_0 + 1}$
c.
$\frac{N_e\mu_0}{4N_e\mu_0 + 1}$
d.
$\frac{4N_e\mu_0}{(4N_e\mu_0 - 1)}$
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As cancer progresses, several genome rearrangements including translocation, deletion, duplications etc. occur. If these rearrangements are to be identified, which of the following techniques would be most suitable?
a.
RAPD
b.
Microarray
c.
Multi-colour FISH
d.
Flow cytometry
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A student noted the following points regarding *Agrobacterium tumefaciens*:
A. *A. tumefaciens* is a gram-negative soil bacterium.
B. Opine catabolism genes are present in T-DNA region of Ti-plasmid.
C. Opines are synthesized by condensation of amino acids and $\alpha$-ketoacids or amino acids and sugars.
D. A callus culture of crown gall tissue casued by *A. tumefaciens* in plants can be multiplied without adding phytohormones.
Which one of the combinations of above statements is correct?
a.
A, B and C
b.
A, B and D
c.
B, C and D
d.
A, C and D
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A mixture of two proteins was subjected to following three chromatographic columns: a) Cation exchange, b) Size exclusion (Sephadex 100) and (c) Reverse phase. Following elution profiles were obtained
Which of the following statements is correct?
a.
A is larger and more hydrophobic than B.
b.
B is more anionic and more hydrophobic than A.
c.
A is more hydrophobic and smaller than B.
d.
A is more cationic and smaller than B.
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Glucose in the blood is detected by four different methods (a, b, c and d). The sensitivity and range of detection of glucose by these four methods is shown below. Clinically relevant concentration of glucose in blood is between $80 - 250\text{ mg/dL}$
Which of the following method is most appropriate?
a.
a
b.
b
c.
c
d.
d
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The following statements are related to plant tissue culture
A. Friable callus provides the inoculum to form cell-suspension cultures.
B. The process known as 'habituation' refers to the property of callus losing the requirement of auxin and/or cytokinin during long term culture.
C. Cellulase and pectinase enzymes are usually used for generating protoplast cultures.
D. During somatic embryo development, torpedo stage embryo is formed before heart stage embryo.
Which one of the following combinations of above statements is correct?
a.
A, B and C
b.
A, B and D
c.
A, C and D
d.
B, C and D
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A researcher is studying the subcellular localization of a particular protein ‘X’ in an animal cell. The researcher performs successive centrifugation at increasing rotor speed. The researcher starts spinning the cellular homogenate at $600\text{ g}$ for $10\text{ min}$, collects the pellet, spins the supernatant at $10,000\text{ g}$ for $20\text{ min}$, collects the pellet, spins the supernatant at $100,000\text{ g}$ for $1\text{ hour}$, collects both the pellet and the final supernatant. On subjecting various pellets and the final supernatant to Western blotting with anti-protein-X antibody, the protein X is observed to be maximally expressed in pellet after centrifugation at $10,000\text{ g}$. Based on the above observation, what will be the most likely localization of protein X.
a.
Nucleus
b.
Ribosomes
c.
Mitochondria
d.
Microsomes
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You have transiently expressed a new protein (for which no antibody is available) in a cell line to establish structure function relationship. Which one of the following strategies is the most straight forward way to examine the expression profile of this new protein?
a.
By metabolic labelling using $^{35}\text{S}$ labelled amino acids
b.
Making a GFP fusion protein with this new protein
c.
Immunoprecipitating this protein with the help of another protein for which antibody is available
d.
Running SDS-PAGE and identify the protein
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During an experiment, a student found increased activity of a protein, for which there were three possible explanations, viz., increased expression of the protein, increased phosphorylation, or increased interaction with other effector proteins. After conducting several experiments, the student concluded that increased activity was due to increased phosphorylation. Which one of the following experiments will NOT support/provide the correct explanation drawn by the student?
a.
Western blot analysis
b.
Analysis of transcription rate
c.
Mass spectroscopy
d.
Phospho amino acid analysis
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