CSIR NET Life Science Previous Year Questions on applied biology Archives - Page 10 of 19 - CSIR NET LIFE SCIENCE COACHING | NTA NET LIFE SCIENCE

13. Which one of the following statements related to genetic transformation of plants is correct? (1) Negative selection markers need to be expressed only under strong constitutive promoter development of transgenic plants (2) A transgenic plant containing two linked copies of the transgene in heterozygous condition would segregate in a 3:1(transgenic: non- transgenic) ratio for the transgenic phenotype on pollination. (3) Agrobacterium -mediated transfer of T-DNA into a host plant does not require host plant proteins. (4) In a binary vector system of Agrobacterium tumefaciens, the oncogenes are located on the Helper plasmid.

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Key facts about plant transformation, segregation, and Agrobacterium binary vectors

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November 29, 2025
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Which one of the following statements related to genetic transformation of plants is correct? (1) Negative selection markers need to be expressed only under strong constitutive promoter development of transgenic […]

12. ATO transgenic plant containing a transgene for herbicide resistance shows two bands on Southern blot analysis using a probe that is internal to the restriction sites used for genomic DNA digestion. However, it segregates in a 3: 1 ratio for herbicide resistance: sensitivity in the T1 progeny obtained by self- pollination. Which one of the following statements is correct? (1) The T0 plant is a single-copy event (2) The T0 plant is a double-copy event and the two transgene copies are tightly linked (3) The T0 plant is a double-copy event and the two transgene copies are integrated in two different chromosomes (4) The T0 plant contains two unlinked copies of the transgene, both of which are truncated versions of the herbicide resistance gene.

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Interpreting Southern blot and segregation data for herbicide‑resistant transgenic plants

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November 29, 2025
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ATO transgenic plant containing a transgene for herbicide resistance shows two bands on Southern blot analysis using a probe that is internal to the restriction sites used for genomic DNA […]

11. Given below are four statements regarding genetic transformation of plants in the laboratory: (A) Plants incapable of sexual reproduction cannot be transformed by Agrobacterium tumefaciens (B) Integration of transgene in organellar (chloroplast) genome occurs primarily by homologous recombination (C) An enhancer trap construct used in Agrobacterium- mediated transformation would contain a functional coding sequence of a reporter gene and a minimal promoter (D) A T0 transgenic plant containing two unlinked copies of a selection marker gene (hpt) and one copy of the passenger gene (gfp) would segregate in a 1 : 1 ratio for hygromycin resistance: sensitivity in the backcrossed progeny grown on selection media Which one of the combinations of above statements are correct? (1) A and D (2) B and C (3) A and C (4) B and D

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Key facts about plant transformation, chloroplast integration, enhancer traps, and segregation of marker genes

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November 29, 2025
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Given below are four statements regarding genetic transformation of plants in the laboratory: (A) Plants incapable of sexual reproduction cannot be transformed by Agrobacterium tumefaciens (B) Integration of transgene in […]

10. A transgenic plant having a homozygous single-copy insertion for trait A was re- transformed by Agrobacterium-mediated transformation with a gene conferring trait B. Given below are a few statements regarding the above experiment: A. All T0 transgenic plants obtained after re- transformation would be single copy events for both traits, A and B. B. T1 progeny generated by self-pollination of single- copy transgenic plants obtained by retransformation would segregate in a 3:1 ratio for trait A. C. Plant selection marker genes used for transformation experiments for both traits, A and B should be necessarily identical. Different selection marker genes cannot be used. D. 25% of T1 progeny generated by self-pollination of single-copy transgenic plants obtained by retransformation would be homozygous for both traits, A and B. Which one of the following options represents all INCORRECT statements? (1) A, C and D (2) A, B and C (3) D only (4) A and C only

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Retransformation of a single-copy transgenic plant – segregation of traits A and B

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November 29, 2025
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A transgenic plant having a homozygous single-copy insertion for trait A was re- transformed by Agrobacterium-mediated transformation with a gene conferring trait B. Given below are a few statements regarding […]

9. Given below are some statements that are associated with transgenic plants. Each statement has a blank space indicated by '_______'. A. A transgenic plant with two functional copies of a transgene can segregate in a _______ ratio for the transgenic phenotype on self-pollination if the two genes are linked. B. The _______ system can be used for removal of marker genes from transgenic plants. C. The endogenous plant gene,_____, can be used to engineer resistance to imidazolinone herbicides. D. Variations in transgene expression levels between five independent transgenic lines generated using the same T-DNA construct can be due to _______ Which one of the following options has the correct sequence of terms that can be used to fill in the blanks in the above statements (from A to D) such that all statements become true? (1) A-9:3:3:1; B-Cre/loxP: C-ALS: D-codon usage of the transgene (2) A-3:1; B-FLP/FRT; C-bar; D-copy number of transgene (3) A-3:1; B-Cre/loxP: C-ALS; D-position effect (4) A-1:2:1; B-FLP/FRT; C-EPSPS; D-position effect

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Key concepts in transgenic plant genetics and marker removal

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November 29, 2025
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Given below are some statements that are associated with transgenic plants. Each statement has a blank space indicated by ‘_______’. A. A transgenic plant with two functional copies of a […]

8. A To transgenic plant contains two unlinked copies of the T- DNA of which one is functional and the other is silenced. Segregation of the transgenic to non-transgenic phenotype would occur in a (i) Ratio in progeny obtained by backcrossing and in a (ii) Ration in F1 progeny obtained by self- pollination. Fill in the blanks with the correct combination of (i) and (ii) from the options given below: (1) (i) — 3:1 and (ii)— 15 : 1 (2) (i)— 1:1 and (ii) -- 3 : l (3) (i)—3:1 and (ii) —3:1 (4) (i) —1:1 and (ii) -15 : 1

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Segregation ratios for a transgenic plant carrying two unlinked T-DNA copies

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November 29, 2025
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A To transgenic plant contains two unlinked copies of the T- DNA of which one is functional and the other is silenced. Segregation of the transgenic to non-transgenic phenotype would […]

7. Given below is a schematic representation of a Southern blot performed to identify single copy integration events of the T-DNA among six transgenic plants (T1 — T6). Which one of the following options represent potential single copy events? (1) T1, T5 and T6 (2) T2 and T3 (3) T4 only (4) T1 only

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Identifying single-copy T-DNA insertions from a Southern blot (T₁–T₆ lines)

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November 29, 2025
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Given below is a schematic representation of a Southern blot performed to identify single copy integration events of the T-DNA among six transgenic plants (T1 — T6). Which one of […]

6. Given below is a schematic representation of the T-DNA region of a binary vector used for genetic transformation of plants. LB: Left Border, RB: Right Border, M: Marker gene, P: Passenger gene, pA: poly-adenylation signal, Pr1: promoter of M gene Pr2: Promoter of P gene, E: Restriction enzyme (sites) used for digestion of genomic DNA for Southern blotting, Probe 1 and Probe 2: probes used for Southern blotting. Transgenic plants generated using the above construct were subjected to Southern hybridization following digestion of genomic DNA with restriction enzyme 'E', to identify true single copy integration events from LB and RB flanks of the DNA. Based on the above information, the following statements are made: (A) Single copy events from the LB flank identified using Probe 1 would show two hybridization bands on THE Southern blot. (B) Single copy events from the RB flank identified using Probe 2 would show a single hybridization band on the Southern blot. (C) For true single copy events, one hybridization band would be of the same length for each of the two probes used for hybridization. (D) True single copy events would show two bands each for copy number on the left border and right border flanks. (E) There would be no similar hybridization band obtained using Probe 1 and Probe 2. Which one of the following options represents only correct statements? (1) A, B and D (2) C, D and E (3) B, C and E (4) A, C and D

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Using Southern blot with LB/RB probes to detect true single-copy T‑DNA insertions

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November 29, 2025
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Given below is a schematic representation of the T-DNA region of a binary vector used for genetic transformation of plants. LB: Left Border, RB: Right Border, M: Marker gene, P: […]

5. Given below is a schematic representation of the T- DNA region of a transgene construct and the Southern blot analysis (using Pst l digested genomic DNA) of five independent transgenic lines (labelled as A to E) developed using the construct. The probe used for hybridization is shown as a black box below the construct (UT: Untransformed Plant) Based on the above data, which one of the following options gives the correct list of single insertion transgenic events? (1) B and C only (2) A, B and E only (3) A and B only (4) E only

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Identifying single-copy T-DNA insertions from Southern blot patterns

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November 29, 2025
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Given below is a schematic representation of the T- DNA region of a transgene construct and the Southern blot analysis (using Pst l digested genomic DNA) of five independent transgenic […]

4. Genomic DNA of transgenic plants (P1, P2 and P3) obtained by transforming with binary vector A whose map is depicted below, was digested with BamH I and Sal I and hybridized with genomic fragment X Pattern obtained in Southern hybridization is shown below Based on the above, which of the following interpretation is correct: (1) All the plants (P1, P2 and P3) contains two copies of the transgene (2) P1, P3 contains one and P2 contains two copies of the transgene (3) P1 contains two, whereas P2 and P3 contains one copy of transgene each (4) P1 and P2 contains two and P3 contains one copy of the trangene

CSIR NET Life Science Previous Year Questions and Solution on applied biology

Using Southern blot patterns to estimate transgene copy number in plants

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November 28, 2025
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Genomic DNA of transgenic plants (P1, P2 and P3) obtained by transforming with binary vector A whose map is depicted below, was digested with BamH I and Sal I and […]

Tag: CSIR NET Life Science Previous Year Questions on applied biology

Key facts about plant transformation, segregation, and Agrobacterium binary vectors

Interpreting Southern blot and segregation data for herbicide‑resistant transgenic plants

Key facts about plant transformation, chloroplast integration, enhancer traps, and segregation of marker genes

Retransformation of a single-copy transgenic plant – segregation of traits A and B

Key concepts in transgenic plant genetics and marker removal

Segregation ratios for a transgenic plant carrying two unlinked T-DNA copies

Identifying single-copy T-DNA insertions from a Southern blot (T₁–T₆ lines)

Using Southern blot with LB/RB probes to detect true single-copy T‑DNA insertions

Identifying single-copy T-DNA insertions from Southern blot patterns

Using Southern blot patterns to estimate transgene copy number in plants

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