Notes | EduRev

NEET Revision Notes

NEET : Notes | EduRev

The document Notes | EduRev is a part of the NEET Course NEET Revision Notes.
All you need of NEET at this link: NEET

Multiple Choice Questions

Q.1. All eukaryotic unicellular organisms belong to
(a) Monera
(b) Protista
(c) Fungi
(d) Bacteria
Ans.
(b) Protista
Solution:
Monera: Kingdom of prokaryotes.
All eukaryotic unicellular organisms belong to Protista. Notes | EduRevProtista


Q.2. The five-kingdom classification was proposed by
(a) R.H. Whittaker
(b) C. Linnaeus
(c) A. Roxberg
(d) Virchow
Ans. 
(a) R.H. Whittaker
Solution.
This phylogenetic classification was proposed by R.H. Whittaker (1969). He created a new kingdom ‘Fungi’.
The five-kingdom classification is as follows:
(i) Monera
(ii) Protista
(iii) Fungi
(iv) Plantae
(v) Animalia
 Notes | EduRev

Whittaker has used 5 criteria for the 5 kingdom classification and are as follows:
(i) Reproduction
(ii) Cell structure
(iii) Phylogenetic relationships
(iv) Mode of nutrition
(v) Thallus organisation


Q.3. Organisms living in salty areas are called:
(a) Methanogens
(b) Halophiles
(c) Heliophytes
(d) Thermoacidophiles

Ans. (b) Halophiles
Solution. 

  • Halophiles: Bacteria living in extremely salty areas.
  • Thermoacidophiles: Bacteria living in hot springs/deep seawater.
    Example: Thermococcus
  • Methanogens: Bacteria living in marshy areas and produce methane gas.
  • Heliophytes: Sun-loving plants

Q.4. Naked cytoplasm, multi-nucleated and saprophytic are the characteristics of
(a) Monerans
(b) Protists
(c) Fungi
(d) Slime moulds
Ans.
(d) Slime moulds
Solution.
Slime moulds are saprophytic protists, without cell walls. The spores of slime moulds possess true walls. Thalloid multinucleate body of a slime mould is called Plasmodium. Spores are dispersed by air currents.

Example: 
(i) Acellular slime mould: Physarum
(ii) Cellular slime mould: Dictyostelium

Q.5. An association between roots of higher plants and fungi is called
(a) Lichen
(b) Fern
(c) Mycorrhiza
(d) BGA
Ans. 
(c) Mycorrhiza
Solution.

  • The association of fungi with the roots of higher plants usually gymnosperms are known as Mycorrhiza.
  • Lichens are symbiotic associations, i.e. mutually useful associations, between algae and fungi. This relationship is best known as helotism.


Q.6. A Dikaryon is formed when
(a) Meiosis is arrested
(b) The two haploid cells do not fuse immediately
(c) Cytoplasm does not fuse
(d) None of the above
Ans. 
(b) The two haploid cells do not fuse immediately
Solution.
In some fungi, the fusion of two haploid cells immediately results in diploid cells (2n). However, in other fungi (ascomycetes and basidiomycetes), an intervening dikaryotic stage (n + n, i.e. two nuclei per cell) occurs. Such a condition is called a dikaryon and the phase is called dikaryo phase of fungus. A dikaryotic cell has two dissimilar haploid nuclei.

Q.7. Contagium vivum fluidum was proposed by
(a) D. J. Ivanowsky
(b) M. W. Beijerinek
(c) Stanley
(d) Robert Hooke
Ans.
(b) M. W. Beijerinek
Solution.

  • D.J. Ivanowsky (1892) discovered the virus and has recognised certain microbes as a causal organism of the mosaic disease of tobacco. 
  • M.W. Beijerinck (1898) demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants and called the fluid as Contagium vivum fluidum (infectious living fluid). 
  • W. M. Stanley (1935) first time showed that viruses could be crystallized and crystals consist largely of proteins.

Q.8. Association between mycobiont and phycobiont are found in
(a) Mycorrhiza
(b) Root
(c) Lichens
(d) BGA
Ans. 
(c) Lichens
Solution.
Association between mycobiont and phycobiont are found in lichens.

Q.9. Difference between Virus and Viroid is
(a) Absence of protein coat in viroid but present in the virus.
(b) Presence of low molecular weight RNA in the virus but absent in viroid.
(c) Both (a) and (b)
(d) None of the above.
Ans.
(a) Absence of protein coat in viroid but present in the virus.
Solution.
Viroids are smaller than viruses and the cause of potato spindle tuber disease, chrysanthemum stunt disease. It was found to be a free RNA and lacked the protein coat that is found in viruses, hence the name viroid.
 Notes | EduRev


Q.10. With respect to the fungal sexual cycle, choose the correct sequence of events.
(a) Karyogamy, Plasmogamy and meiosis
(b) Meiosis, Plasmogamy and Karyogamy
(c) Plasmogamy, Karyogamy and Meiosis
(d) Meiosis, Karyogamy and Plasmogamy
Ans. (c) Plasmogamy, Karyogamy and Meiosis
Solution.
The sexual cycle involves the following three steps:
(i) The fusion of protoplasms between two motile or non-motile gametes called plasmogamy. Plasmogamy is the fusion of two haploid cells without nuclear fusion.
(ii) Fusion of two nuclei is called Karyogamy.
(iii) Meiosis in zygote resulting in haploid spores.


Q.11. Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?
(a) Monera
(b) Protista
(c) Fungi
(d) None of these
Ans. 
(d) None of these
Solution.

  • Viruses did not find a place in classification since they are not truly ‘living’ if we understand living as those organisms that have a cell structure. 
  • Viruses are neither prokaryotes nor eukaryotes. 
  • They are inert outside their specific host cell and cannot multiply of their own because they lack cellular machinery to use its genetic material. Viruses can only multiply in host or living cell.

Q.12. Members of Phycomycetes are found in
(i) Aquatic habitats
(ii) On decaying wood
(iii) Moist and damp places
(iv) As obligate parasites on plants 

Choose from the following options:
(a) None of the above
(b) (i) and (iv)
(c) (ii) and (iii)
(d) All of the above
Ans.
(d) All of the above
Solution.
Members of Phycomycetes are found in aquatic habitats, on decaying wood, moist and damp places and as obligate parasites on plants.


Very Short Answer Type Questions

Q.1. What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?

Ans. 

  • Cyanobacteria (BGA) are autotrophic microbes. 
  • Cyanobacteria are widely distributed in aquatic and terrestrial environments. 
  • Nostoc, Ariabaena and Oscillatoria are BGA that can fix atmospheric nitrogen. 
  • These organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena. 
  • In paddy fields, cyanobacteria serve as an important biofertiliser. 
  • BGA also add organic matter to the soil and increase its fertility.

Q.2. Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you place the slide under the microscope and observe the following features:
(a) Unicellular
(b) Well defined nucleus
(c) Biflagellate—one flagellum lying longitudinally and the other transversely.
What would you identify it as? Can you name the kingdom it belongs to?
Ans. 

  • Dinoflagellates are unicellular eukaryotes.
  • Most of them have two flagella:
    One lies longitudinally and the other transversely in a furrow between the wall plates.
  • Well-defined nucleus organisms are eukaryotes and unicellular organisms with eukaryotic cellular structure come under Protists.
  • Dinoflagellates belong to kingdom Protista.


Q.3. How is the five-kingdom classification advantageous over the two kingdom classification?
Ans. 
Two Kingdom system of classification with Plantae and Animalia kingdoms.

  • Two kingdom classification did not distinguish between the prokaryotes and eukaryotes.
    Example: It brought together the prokaryotic bacteria and blue-green algae with other groups (like plant, fungi and animals) which were eukaryotic.
  • Two kingdom classification did not distinguish between the unicellular and multicellular organisms.
    Example: Chlamydomonas (unicellular) and Spirogyra (multicellular) were placed together under algae.
  • This system did not distinguish between autotrophic/photosynthetic (green algae and plants) and the heterotrophic/non-photosynthetic organisms (fungi).

Five Kingdom Classification:
(i) Fungi were placed in a separate kingdom—kingdom fungi.
(ii) It has put together, organisms which were placed in different kingdoms in earlier classifications.
(iii) Kingdom Protista brought together Chlamydomonas, Chlorella (earlier placed in algae within plants and both having cell walls) with Amoeba and Paramoecium (earlier placed in the animal kingdom and both lacking cell walls).
(iv) Animal and plant kingdoms become more homogenous than they are in the two kingdom classification. So, it is advantageous over the two kingdom classification.


Q.4. Polluted water bodies have usually a very high abundance of plants like Nostoc and Oscillatoria. Give reasons.
Ans. 

  • Polluted water bodies (ponds, ditches and rivers etc.) usually have nutrient contents (such as nitrate, phosphates). 
  • Domestic sewage primarily contains biodegradable organic matter. Presence of a large amount of nutrients in waters also causes excessive growth of planktons (free-floating algae) called an algal bloom, which imparts a distinct colour to water bodies. Notes | EduRevAlgal Bloom
  • Algal bloom causes deterioration of water quality and fish mortality. Some bloom-forming algae, mainly Nostoc and Oscillitoria are extremely toxic to human beings and animals.


Q.5. Are chemosynthetic bacteria—autotrophic or heterotrophic?
Ans. Chemosynthetic bacteria oxidise various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production. So chemosynthetic bacteria are autotrophic in nature.


Q.6. The common name of pea is simpler than its botanical (scientific) name Pisum sativum. Why then is the simpler common name not used instead of the complex scientific/botanical name in biology?
Ans. As we know that pea (vernacular name or local name) is simpler than its botanical (scientific) name Pisum sativum. These local names would vary from place to place, even within a country. 

One would probably recognize the confusion that would be created if we did not find ways and means to talk to each other and refer to organisms we are talking about.

Hence, there is a need to standardize the naming of living organisms such that a particular organism is known by the same name all over the world.


Q.7. A virus is considered as a living organism and an obligate parasite when inside a host cell. But the virus is not classified along with bacteria or fungi. What are the characters of the virus that are similar to non-living objects?
Ans. Viruses are living organisms inside a host cell. But the virus is not classified along with bacteria or fungi because they have an inert crystalline structure outside the living cell. They are inert outside their specific host cell and cannot multiply of their own because they lack cellular machinery to use its genetic material.

Q.8. In the five-kingdom system of Whittaker, how many kingdoms are eukaryotes?
Ans. 
In Whittaker's five-kingdom system, four kingdoms (Protista, Fungi, Plantae and Animalia) belong to eukaryotes.

 Notes | EduRev

Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Related Searches

Sample Paper

,

Semester Notes

,

ppt

,

Viva Questions

,

practice quizzes

,

Notes | EduRev

,

Summary

,

mock tests for examination

,

past year papers

,

Previous Year Questions with Solutions

,

video lectures

,

MCQs

,

pdf

,

study material

,

Exam

,

Important questions

,

Objective type Questions

,

Extra Questions

,

shortcuts and tricks

,

Free

,

Notes | EduRev

,

Notes | EduRev

;