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NEET & AIIMS Solved Previous Year Papers By - Tuhi S. Mishra
Select the correct statement: Franklin Stahl coined the termm "linkage Punnett square was developed by a British scientist. Spliceosomes take part in translation Transduction was discovered by S. Altman
CORRECT ANSWER : B Reginald Crundall Punnett was a British geneticist who developed Punnett square to depict the number and variety of genetic combinations and played a role in shaping the Hardy-Weinberg law. .The term linkage was coined by T.H. Morgan while Franklin Stahl with Meselson prove that DNA replication is semi-conservative using heavy nitrogen in E.coli.
Transduction was discovered by Norton Zinder and Joshua Lederberg and S. Altman discovered the catalytic property of RNA. .Spliceosome takes part in transcription mainly for the removal of non - coding region or intron, during transcription of DNA to RNA.
Offsets are produced by A)Meiotic divisions B Mitotic divisions C Parthenocarpy D Parthenogenesis
CORRECT ANSWER : B An Offsets is the sub-aerial modification of the vegetative part of the stem or small complete daughter plant which remains attached to the mother body produced asexually and are genetically similar to the mother plant. This is a natural means of cloning. They are produced by mitotic division occurring in the meristematic cells of the mother plant. Plants which are produced through offsets are Lillies and Tulips.
Which of the following pairs in wrongly matched? Starch synthesiS in pea: Multiple alleles ABO blood grouping: Co-dominance XO type sex determination Grasshopper D T.H Morgan: Linkage
CORRECT ANSWER: A The gene controlling starch synthesis in pea shows a small degree of pleiotropy. Starch syntnesis in pea seeds is controlled by one gene. It has two alleles B and b. Parent Gamates F1 generation Bb B,B b,b Bb Selfing F2 generation BI BB Bb b Bb
Starch is synthesized effectively by BB homozygotes and therefore, large starch grains are produced. In contrast, bb homozygotes nave lesser efficiency in starch synthesis and produce small starch grains. After maturation of the seeds, BB seeds are round and the bb seeds are wrinkled Heterozygotes Bb form round seeds but the starch grains are of intermediates size. It starch grain size is considered, Bb seed shows incomplete dominance but if seed shape is considered, B allele is dominant and b is recessive.
Which of the following flowers only once in its life-time? A Bamboo species B Jackfruit C Mango D Papaya
CORRECT ANSWER: A Monocarpic plants, flower once in a lifetime. Bamboos, an example of monocarpic plants which usually dies after flowering. Bamboo has a lifecycle around 40 to 80 years, varying among species. Normally, new bamboos grow up from bamboo shoots at the roots. While mango, jackfruit and Papaya are an example of Polycapic plants that not die after flowering and fruiting and flower every year in particular season.
CORRECT ANSWER: D In 1961, Francois Jacob and Jacques Monod proposed the operon model of gene regulation in bacteria. The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose whern glucose is not available through the activity of beta-Galactosidase. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation.
Alec Jeffreys develope techniques for genetic fingerprinting used in the laboratory to establish a ink between biological evidence and a suspect in a criminal investigation. Alfred Hershey and Martha Chase, through their experiment final proof DNA as the genetic material in which Bacteriophages, were the key element tor their experiment.
Alfred Hershey and Martha Chase, through their experiment final proof DNA as the genetic material in which Bacteriophages, were the key element for their experiment. Meselson and Stahl experiment supported Watson and Crick's hypothesis that DNA replication was semiconservative. They conducted their experiment using an isotope of nitrogen to distinguish between parent and newly copied DNA
CORRECT ANSWER:D Pollen grains are the thicked walled microspores and surrounded by two distinct wall layers. The outer wall layer is thick and rigid called the Exine, which is made up of sporopollenin and the inner wall of pollen grains is thin, soft and elastic in nature called intine, which is made up of cellulose.
Sporopollenin is most resistant organic materials and non- biodegradable. It can withstand high temperatures and strong acids and alkali. So far no enzyme that degrades sporopollenin is known. Due to the presence of sporopollenin the fossils of pollen grains are found in good conditions. The presence of fossils of the pollen grains, make the possibility to forecast the presence of natural resources in the earth.
Stomatal movement is not affected by A Temperature B Light C O concentration D CO concentration 2
CORRECT ANSWER: C Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore. The stomatal pores are largest when water is freely available and the guard cells turgid and closed when water availability is critically low and the guard cells become flaccid.
Photosynthesis depends on the diffusion of carbon dioxide (CO2) from the air through the stomata into the mesophyll tissues light stimulates the process of transpiration by the heating effect on the leaf. The rate of respiration is faster in blue light than that of red. Because the stomata are completely opened as their full capacity in the blue light.
Tuhi S. Mishra Verified Educator In Unacademy M.Sc. Botany (Gold Medalist) CET, DCA & B.Ed. 8 Yrs. of Biology Teaching Experience
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NEET 2018 Solved Paper Part 1 Biology Section)