Free Net Life Science Study Materials

NET Life Sciences Model Question Paper June 2017 Set- 3

Life Science JRF Model Questions

CSIR JRF/NET Life Science Exam December 2017 (II)
Model Question Paper 3/5

(CSIR MCQ014: Practice Questions with Answer Key)

(1). A flow cytometer is used to measure the number of

a.       Cells
b.      DNA
c.       RNA
d.      Proteins

(2). How many H atoms would be replaced CCl4 in presence of ethanol during NMR spectrum?

a.       1
b.      2
c.       3
d.      4

(3). During the regulation of trp operon by the attenuation process, there is

a.       Immature termination of translation
b.      Immature termination of transcription
c.       Termination of replication
d.      Ribosome fails to read transcript

(4). An embryo lacking the bicoid is injected with bicoid m‐RNA at the middle portion. It will result in the formation of _______.

a.       Two heads and no tarsons
b.      Head in the middle and tarsons at both the ends
c.       No head and tarson at both ends
d.      Normal phenotype

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Free Net Life Science Study Materials

JRF NET Life Sciences June 2017 Free Model Question Papers Set- 2

NET Life Sciences Practice Questions

CSIR JRF/NET Life Science Exam December 2017 (II)
Model Question Paper 2/5

(CSIR MCQ013: Practice Questions with Answer Key)

You might like: NET Life Sciences Previous Year Papers (Download PDF)

(1). Most of the DNA binding protein binds to DNA by particular motif to modulate gene expression. Genes which are under the regulation of gibberllic acid have GRE where, GREB binds. The motif in GREB is ______

a.       Leucine Zipper
b.      bZIP
c.       Zinc finger
d.      Homoedomain

(2). Which of the following DONOT occur during seed development?

a.       Accumulation of storage proteins
b.      Synthesis of LEA proteins
c.       Desiccation
d.      Synthesis of Gibberellic acid

(3). The chemical salicyl hydroxamic acid inhibits

a.       Cytochrome oxidase
b.      Alternative oxidase
c.       ATP synthase
d.      NADH‐dehydrogenase

(4). Hardy‐Weinberg law will NOT operate under conditions¸ when

a.       3 alleles are involved
b.      Weak selection of one of the allele
c.       Skewed sex ratio
d.      Mutated allele is not involved in sexual selection

Learn more: Hardy Weinberg Equilibrium (easy explanation)

(5). Chromatids appear in the form of dyads during:

a.       Metaphase of mitosis
b.      Metaphase of meiosis
c.       Prophase of mitosis
d.      Anaphase of mitosis

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Free Net Life Science Study Materials

CSIR JRF NET Life Sciences December 2017 Model Question Paper Set- 1

NET 2017 Model Paper Life Sciences

CSIR JRF/NET Life Science Exam: Dec 2017
Model Question Paper 1/5

(CSIR MCQ012: Practice Questions with Answer Key)

(1).  The characteristics of organisms the reaches first to barren Island during the ecological succession:

a.       Slow growth and small generation time
b.      Slow growth and large generation time
c.       Fast growth and small generation time
d.      Fast growth and large generation time

Learn more: Process of Ecological Succession

(2). A myopic person is also suffering from astigmatism, to correct his vision which lens must be used:

a.       Plano-concave lens
b.      Plano-convex lens
c.       Combination of concave and cylindrical lens
d.      Combination of convex and cylindrical lens

(3). Fossil gives a better idea regarding the age of rocks because:

a.       Organic evolution is irreversible
b.      Rocks are formed after fossil deposition
c.       Rocks with fossils are stable
d.      Fossils do not allow weathering of rocks

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Botany lecture notes

Difference between Microspores and Megaspores: Comparison Table

microspores vs megaspores

Microspores vs Megaspores
(Similarities and Differences between Microspores and Megaspores)

Microspores and megaspores are sexual spores produced by vascular plants (some Pteridophytes and all Gymnosperms and Angiosperms) for sexual reproduction. Both microspores and megaspores on germination produce the respective gametophytic generations. The gametophytes on maturation produce sex organs and gametes to establish the fertilization and thus to complete the life cycle.

The production of different types of spores with different functions and sexuality is called Heterospory. The heterosporous condition was first evolved in Pteridophytes and it is considered as the prerequisite for seed habitat.

Learn more: Heterospory and Seed Habitat

The present post discusses the similarities and differences between microspores and megaspores with a comparison table.

Similarities between Microspores and Megaspores

Ø  Both microspores and megaspores are sexual spores.

Ø  Both are produced by the diploid sporophytic plants.

Ø  Both are haploid spores produced after reduction division of spore mother cells.

Ø  Both spores are produced in specialized structures called sporangium.

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Difference between Phase Contrast Microscopy and Differential Interference Contrast Microscopy: (Easy Short Notes)

Phase Contrast vs DIC Microscopy

Phase Contrast Microscope vs Differential Interference Contrast Microscope
(Similarities and Differences between Phase Contrast Microscope and Differential Interference Contrast (DIC) Microscope)

Phase Contrast and Differential Contrast Microscopes

Phase contrast microscopy and Differential Interference Contrast (DIC) microscopy are two advanced optical light microscopy techniques to produce high contrast images of unstained and living cells. Both the microscopes utilize various contrast enhancing techniques to produce high contrast images.

Phase contrast microscopy is an optical-microscopy technique developed by Frits Zernike in 1934 to produce high contrast images of unstained live specimens. The phase contrast microscopy works by converting the phase shifts of light passing through a transparent specimen to detectable brightness changes in the image.

Differential Interference Contrast (DIC) microscopy, also called as Nomarski Interference Contrast (NIC) Microscopy, was first invented by Georges Nomarski in 1952. DIC microscopy uses more sophisticated contrast enhancing techniques than phase contrast system. It works by separating a polarized light source into two orthogonally polarized mutually coherent parts which are spatially displaced at the sample plane, and recombined before the final image formation. DIC produce more pronounced contrast difference than phase contrast image.

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