NEET Mock Test | PreMedicalBiology

Q1. chromosomal theory of inheritance was proposed by

A. Sutton and Boveri B. Bateson and Punnett C. TH Morgan D. Watson and Crick

Explanation:
Option A is correct. In 1902, chromosomal theory of inheritance was proposed by Sutton and Boveri. They found a close similarity between the transmission of heredity trade and behaviour of chromosome while passing from one generation to the next through them it

Q2. which of the following elements help in maintaining the structure of ribosomes ?

A. magnesium B. zinc C. copper D. molybdenum

Explanation:
Option A is correct. Each ribosomes consists of two unequal subunits a larger and a smaller one and magnesium ions are required for binding the two subunits

Q3. which of the following are found in extreme saline conditions ?

A. archaebacteria B. eubacteria C. cyanobacteria D. mycobacteria

Explanation:
option A is correct. archaebacteria are the most primitive form of bacteria found in divers Habitat such as hot temperature, saline condition and variable PH

Q4. the structure that help some bacteria to attach to rock and host tissue are

A. rhizoids B. fimbriae C. mesosomes D. holdfast

Explanation:
option B is correct. fimbriae are small bristle like fibres comming out on the cell, they are known to help is attachment to rocks in steams and also in the host tissue.

Q5. in eubacteria a cellular component that resembles eukaryotic cells is

A. nucleus B. ribosomes C. cell wall D. plasma membrane

Explanation:
option D is correct. the plasma membrane of eubacteria is resembles to that of Eukaryotic cell. it is made of protein, polysaccharides and phospholipid.

Q6. pick up the wrong statement :

A. cell wall is absent in animalia B. protista have photosynthesis and heterotrophic mode of nutrition C. some fungi are edible D. nuclear membrane is present in Monera

Explanation:
option D is correct. Monera kingdom contains unicellular organisms with a prokaryotic cell organisation which lacks nuclear membrane and other membrane bounded organelles

Q7. extra nuclear inheritance occurs in

A. killer strain in Paramecium B. color blindness C. phenylketonuria D. tay sachs disease

Explanation:
option A is correct. Paramecium exhibits cytoplasmic inheritance due to the presence of a particles called kappa particles which are self replicating bodies that produce toxing called paramecin

Q8. excretion in Amoeba occurs through :

A. lobopodia B. uroid portion C. plasma membrane D. contractile vacuole

Explanation:
option D is correct. The endoplasm in the posterior part of amoeba, contains a single rounded and pulsating contractile vacuole. Its function in it is excretion and Osmoregulation

Q9. which of the following would appear as the Pioneer organisms on bare rocks ?

A. liverworts B. Mosses C. green algae D. lichens

Explanation:
option D is correct. lichens are Pioneer organisms to colonise the bear rocks. lichens secret acid to dissolve Rocks to helps in weathering and soil formation.

Q10. the highest number of species in the world is represented by :

A. fungi B. Mosses C. algae D. lichens

Explanation:
option A is correct. Fungi represent the highest number of species in the world around 1 lakh

Q11. adhesive pad of fungi penetrates the host with the help of :

A. mechanical pressure and enzymes B. hooks and suckers C. softening by enzymes D. only by mechanical pressure

Explanation:
option A is correct. cell wall degrading enzymes (cellulolytic + pectolytic) as well as mechanical pressure of Adhesive pad helps the fungus to penetrate the host

Q12. in bryophytes and pteridophytes transport of male gamete required :

A. insects B. Birds C. water D. wind

Explanation:
option C is correct. plants like bryophytes, petrodophytes and algae, water is the medium through which male gametes are transferred to the female reproductive organ.

Q13. which one of the following has the highest number of species in nature ?

A. insects B. Birds C. angiosperms D. fungi

Explanation:
option A is correct. Around 70% of all the species recored are animals, insects are the most species rich taxonomic group making more than 70% of that total animal species.

Q14. an important characteristics that hemichordates share with chordates is :

A. absence of notochord B. ventral tubular nerve card C. pharynx with Gill slits D. pharynx Without Gill slits

Explanation:
option C is correct. pharynx with Gill slits. these gill slits are Narrow openings in the pharynx. the position of this pharyngeal gill slits is lateral in chordates while dorsal in hemichordates.

Q15. the long bones are hollow and connected by air passage. These are the characteristics of

A. aves B. mammals C. reptilia D. land vertebrates

Explanation:
option A is correct. The bone of birds (aves) are pneumatic (have air cavities) to reduce weight which help them in flying.

Q16. the infectious stage of plasmodium that enters the human body is

A. sporozoites B. female gametocytes C. male gametocytes D. trophozoites

Explanation:
option A is correct. the infectious stage of plasmodium that enters the human body is sporozoites present in salivary gland of anopheles mosquitoes.

Q17. presence of which of the following conditions in urine are indicative of diabetes mellitus ?

A. uremia and renal calculi B. ketonuria urea and glycosuria C. renal calculi and hyperglycaemia D. uremia and ketonuria

Explanation:
option B is correct. in diabetes mellitus the body produce excessive ketones which indicates that it is using an alternative source of energy. Presence of ketonuria (Ketone bodies) and glycosuria (glucose) in urine are indicative of diabetes mellitus

Q18. who Prove the DNA is basic genetic material ?

A. Griffith B. Watson C. Boveri and Sutton D. Hershey and Chase

Explanation:
option D is correct. DNA is a basic genetic material is proved by Hershey and Chase in 1952

Q19. if one is strand of DNA has the nitrogenous base sequence as ATCTG what would be the complementary RNA stand sequence ?

A. TTAGU B. UAGAC C. AACTG D. ATCGU

Explanation:
option B is correct. if one stand of DNA has the nitrogenous base sequence as ATCTG the complementary sequence of RNA will be UAGAC

Q20. a complex of ribosomes attached to a single strand of RNA is known as

A. polymer B. polypeptide C. Okazaki fragment D. polysome

Explanation:
option D is correct. several ribosomes may attached to single mRNA and form a chain called polyribosomes or polysomes in Prokaryotes.

Q21. the final proof of DNA as a genetic material came from the experiments of :

A. Griffith B. Hershey and Chase C. Avery, McCarty and McLeod D. Hargobind Khorana

Explanation:
option B is correct. DNA as a basic genetic material is proved by Hershey and Chase in 1952

Q22. DNA replication in bacteria occurs

A. during S phase B. within nucleolus C. prior to fission D. just before transcription

Explanation:
option C is correct. Bacteria lack a membrane-bound nucleus and a formal eukaryotic cell cycle, so they do not have a specific S-phase. Instead, DNA replication in bacteria occurs continuously or just prior to binary fission.

Q23. which one of the following statements is not correct ?

A. off springs produced by the Asexual Reproduction are called clone B. microscopic motile sexual reproductive structures are called zoospores C. in potato, banana and Ginger the plantlets arise from the internodes present in the modified stem D. water Hyacinth, growing in the standing water, drains oxygen from water that leads to the death of fishes

Explanation:
option C is correct. In potato, banana and Ginger New plantlets always arise from the nodes of the modified stem. Internodes are the area between the two nodes.

Q24. product of sexual reproduction generally generates :

A. longer viability of seeds B. prolong dormancy C. new genetic combination leading to variation D. large Biomass

Explanation:
option C is correct. Product of Sexual reproduction leads to the new genetic combination leading to variation in new products

Q25. which of the following is not an autoimmune disease ?

A. Alzheimer's disease B. rheumatoid arthritis C. psoriasis D. vitiligo

Explanation:
option A is correct. Alzheimer's disease. it is caused due to the destruction of mass number of neuron in the hippocampus. There is a loss of neurotransmitters acetylcholine. people with the disease have trouble remembering recent events. it occur due to the combination of genetic factors and the aging process.

Q26. in which disease does mosquito transmitted pathogens cause chronic inflammation of lymphatic vessels ?

A. ringworm disease B. ascariasis C. elephantiasis D. amoebiasis

Explanation:
option C is correct. Elephantiasis. this is transmitted by female culex mosquitoes from one individual to the others and the worms live in the lymphatic system.

Q27. which one of the following animals does not undergo metamorphosis ?

A. moth B. tunicate C. earthworm D. Starfish

Explanation:
option C is correct. except earthworm all the given animals undergo metamorphosis. Earthworm exhibit direct development where no larval stages involved. metamorphosis is usually seen in animals exhibiting indirect development.

Q28. which one of the following options correctly represents the lungs conditions in asthma and emphysema respectively ?

A. increased respiratory surface : inflammation of bronchioles B. increase number of bronchioles : increase respiratory surface C. inflammation of bronchioles : decreased respiratory surface D. decrease respiratory surface : inflammation of bronchioles

Explanation:
option C is correct. In asthma there is inflammation of bronchioles. its symptoms include coughing and difficulty in breathing mainly during expiration. In emphysema, many of the septa between the alveoli are destroyed and the elastic tissue of the lungs is replaced by connective tissue. this results to the alveolar septa collapse and the surface area get greatly decreased.

Q29. which part of the brain is responsible for thermoregulation ?

A. hypothalamus B. corpus callosum C. medulla oblongata D. cerebrum

Explanation:
option A is correct. Hypothalamus is the thermoregulatory centre in the brain and its maintains the constant body temperature of 37 degree Celsius.

Q30. cells in G0 phase :

A. enters the cell cycle B. suspend the cell cycle C. Terminate the cell cycle D. exit the cell cycle

Explanation:
option D is correct. G0 phase is the stage in which the cell exist the cell cycle. it is the resting phase in which the cell do not divide. NOTE : neurons and muscle cells, Once these cells reach maturity, they enter a permanent G0 state and generally do not divide again.

Q31. phloem in gymnosperms lacks :

A. sieve tubes only B. companion cells only C. both sieve tubes and companion cells D. albuminous cells and sieve cells

Explanation:
option C is correct. phloem in Gymnosperms lack both sieve tubes and companion cells. Phloem contains albuminous cells and sieve cells in gymnosperms.

Q32. which ecosystem has the maximum Biomass ?

A. forest ecosystem B. grassland ecosystem C. pond ecosystem D. Lake ecosystem

Explanation:
option A is correct. forest ecosystem has the maximum biomass because it includes organisms of all tropical levels.

Q33. the term Ecosystem was coined by

A. AG Tansley B. E Haeckel C. E Warming D. EP Odum

Explanation:
Oprtion A is correct. Ecosystem is a self regulated and self sustain structure and functional unit of nature. the term Ecosystem was coined by AG Tansley in 1935.

Q34. the first human hormone produced by recombination DNA technology is :

A. insulin B. estrogen C. thyroxin D. progesterone

Explanation:
opion A is correct. insulin is the first human hormone produced by recombination DNA technology.

Q35. which of the following Bt crop is being grown in India by the farmers ?

A. maize B. cotton C. brinjal D. soya bean

Explanation:
option B is correct. In India BT Cotton is grown by farmers extensively. other examples of Bt crops are corn, rice, tomato, potato and soyabean.

Q36. which part of the tobacco plant is infected by Meloidegyne incongnitia ?

A. leaf B. stem C. root D. flower

Explanation:
option C is correct. Meloidegyne incongnitia ( a nematode ) : it infects roots of tobacco plant and result in root knot disease.

Q37. the process of separation and purification of expressed protein before marketing is called :

A. upstream processing B. downstream processing C. bio processing D. post production processing

Explanation:
option B is correct. The process of separation and purification of expressed protein before marketing is called downstream processing.

Q38. which of the following is not a component of downstream processing ?

A. separation B. purification C. preservation D. expression

Explanation:
option D is correct. Downstream processes include separation, expression and purification of productS synthesised in bioreactors. hence option D (preservation) is not a component of downstream processing.

Q39. the allele which is unable to express it affect in the presence of another is called :

A. codominant B. supplementary C. complementary D. recessive

Explanation:
option D is correct. in heterozygous condition where both the constants alleles are present only one Alleles is able to express is called dominant while other which remain suppressed is called recessive.

Q40. a person with 47 chromosomes due to an additional Y chromosome suffers from a condition called :

A. Down's syndrome B. super female C. Turner's syndrome D. Klinefelter,s syndrome

Explanation:
option D is correct. Klinefelter,s syndrome

Q41. if both parents are carriers for Thalassaemia which of the an autosomal recessive disorder, what are the chance of pregnancy resulting in the affected child ?

A. no chance B. 50% C. 25% D. 100%

Explanation:
option C is correct. Since both parents carries are haemoglobinopathy trait of Thalassaemia the risk is 25% for each pregnancy for an affected child.

Q42. the core metal of chlorophyll is :

A. Iron B. magnesium C. Nickel D. copper

Explanation:
option B is correct. A Chlorophyll molecule is made up of porphyrin ring, a structure with alternating single and double bonds containing four small pyrrole rings. It has magnesium atom at the centre.

Q43. which is essential for the growth of root tip ?

A. Zn B. Fe C. Ca D. Mn

Explanation:
option C is correct. Calcium is required in the formation of middle lamella of the cell wall present in the form of calcium pectate.

Q44. the first stable product of fixation of atmospheric nitrogen in leguminous :

A. Nitrogen Dioxide B. ammonia C. Nitrate D. Giutamate

Explanation:
option B is correct. the process of conversion of Nitrogen to ammonia is term as nitrogen fixation

Q45. the oxygen evolved during photosynthesis comes from water molecules. which one of the following pairs of element involve in this reaction ?

A. manganese and chlorine B. manganese and potassium C. magnesium and molybdenum D. magnesium and chlorine

Explanation:
option A is correct. Photolysis of water during photosynthesis evolve oxygen in the presence of manganese, calcium and chloride ions. Without these three ions—specifically the manganese, calcium and chloride, the plant would be unable to oxidize water, the flow of electrons would stop, and oxygen would not be released into the atmosphere.

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