- In plants, mosaic formation, leaf rolling and curling, yellowing of plant parts, vein clearing, dwarfing and stunted growth, necrosis etc. are the symptoms of:-
- bacterial diseases
- mycoplasmal diseases
- viral diseases
- fungal diseases
- Fill in the blanks.
I. Retroviruses were discovered by ...A... .
II. ...B... found rabies to be infectious disease and produced anti-rabies vaccine.
III. Prions are highly resistant ...C... particles which functions as infectious agents.
IV. ........D... discovered virus-infecting bacteria. They were named bacteriophages by Herelle.
A, B, C and D in above statements refers to:-- A-Twort, B-Temin, C-Glycoprotein, D-Pasteur
- A-Pasteur, B-Temin, C—Lipid, D-Twort
- A-Temin, B-Pasteur, C-Glycoprotein, D-Twort
- A-Twort, B-Lwoff, C—Lipid, D-Temin
- Viruses that infect bacterial multiplication and cause their lysis, are called:-
- lysozymes
- lipolytic
- lysogenic
- lytic
- Identify the label A, B, C and D in the following figures.
Codes:-- A-Head. B - Collar, C-Sheath, D-Tail fibres
- A-Collar. B-Head, C-Sheath, D-Tail fibres
- A-Head. B-Coilar, C-Tail fibres, D-Sheath
- A-Collai B-Tail fibres, C-Head, D-Sheath
- Which of the following is not a viral disease of plants?
- Red rot of sugarcane
- Tobacco mosaic disease
- Leaf curl of tomato
- Tristeza disease of citrus
- Nucleic acid is absent in :-
- mycoplasma
- viroid
- virus
- prion
- Which one of the following is an incorrect pair?
- Louis Pasteur - Coined the term 'vaccine'
- Beijerinck - Contagium vivum fluidum
- Ivanowsky - Discovered retroviruses
- Stanley - Crystallised TMV
- Read the given statements that describe certain infectious particle.
(i) It was discovered by T.O. Diener and was found to be smaller than viruses.
(ii) It causes potato spindle tuber disease.
(iii) It is a free RNA particle which lacks the protein coat.
(iv) It has low molecular weight RNA as genetic material.
Which of the following is referred to here?- Virus
- Viroid
- Virion
- Bacteriophage
- Given below is the diagram of a virus. In which one of the options, all the three A, B and C (name of the virus) are correct?
- A-RNA, B-Capsomere, C-TMV
- A-DNA, B-Capsid, C-Bacteriophage
- A-RNA, B-Capsid, C-Tobacco mosaic virus
- A-DNA, B-Capsid, C-Bacteriophage
- A virus can be considered a living organism because it :-
- responds to touch stimulus
- reproduces (inside the host)
- can cause disease
- respires
- In an experiment, common Tobacco Mosaic Virus (TMV and its mutant strain 'HR' were used to prepare hybrid particles with 'HR' nucleic acid and 'TMV protein coat. These hybrids were mixed with antibodies against 'HF strains. If this mixture is applied to plant materials, it will result in
- loss of infectivity of virus particles due to inactivatior of nucleic acids.
- loss of infectivity due to inactivation of protein coat
- intact infectivity because only coat is neutralized.
- unchanged infectivity because neither nuclei acid nor
- Read the following statements and select the correct option.
Statement 1 : Viruses are inert crystalline structures outside a living cell.
Statement 2 : Viroids possess a distinct protein coat.- Both, statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
- Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
- Statement 1 is correct and statement 2 is incorrect,
- Both statements 1 and 2 are incorrect.
- Which statement is wrong for viruses?
- All are parasites
- All of them have helical symmetry
- They have ability to synthesize nucleic acids and proteins
- Antibiotics have no effect on them
- Directions : In the following questions, a statement of assertion is followed by a statement of reascr Mark the correct choice as:
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If both assertion and reason are false.
Assertion : Pasteur coined Contagium Vivum Fluidum.
Reason : Pasteur found that virus infected plant of tobacco can cause infection in healthy plant.- a
- b
- c
- d
- Find out the correct statement.:-
- In lichens, the algal component is called phycobiont ana fungal component is known as mycobiont, which are heterotrophic and autotrophic respectively.
- Viroid contains RNA of low molecular weight and protein coat
- A virus always contains both RNA and DNA simultaneously
- Viruses are obligatory parasites
- Which of the following statements regarding viruses are correct?
(i) These are cellular, infectious, nucleoprotien particles
(ii) They can be grown in culture medium.
(iii) Genetic material is either DNA or RNA, but never both.
(iv) They can be crystallised.- (i) and (ii)
- (ii) and (iii)
- (iii) and (iv)
- (i), (ii), (iii) and (iv)
- The proteins that reproduce within the living cells are termed as :-
- Plasmids
- Prions
- Phages
- Prophages
- Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?
- Monera
- Protista
- Fungi
- None of these
- Which statement is not true about methanogens ?
- They are archaebacteria.
- They live in marshy areas.
- Methane is their preferred carbon source.
- They are present in guts of several ruminant animals (cow, buffaloes) and they produce biogas (CH4) from the dung of these animals.
- Antibiotics are mostly obtained from:-
- bacteria
- viruses
- angiosperms
- fungi
- Assertion (A):- Viruses causes diseases and replicate when they are in the host cell.
Reason (R):- Viruses do not replicate outside the host but they remain alive.- Both A and R are true and R is the correct explanation of A
- Both A and R are true, but R is not the correct explanation of A
- A is true, but R is false
- A is false, but R is true
- How many organisms in the list given below are autotrophs?
Lactobacillus, Nostoc, Chara, Nitrosomonas, Nitrobacter, Streptomyces, Saccharomyces, Trypanosomes, Porphyra, Wolffia.- Three
- Four
- Five
- Six
- In bacterial chromosomes, the nucleic acid are:-
- linear DNA molecule
- circular DNA molecule
- of two types DNA and RNA
- linear RNA molecule
- Smallest virus is:-
- Foot and Mouth virus
- Alalfa Mosaic Virus
- Pseudomonas Pf
- TMV
- Which one of the following sets includes the bacterial diseases ?
- Cholera, typhoid, mumps
- Tetanus, tuberculosis, measles
- Malaria, mumps, poliomyelitis
- Diptheria, leprosy, plague
- Difference between virus and viroid is:-
- absence of protein coat in viroid but present in virus
- presence of low molecular weight RNA in virus but absent in viroid
- both (absence of protein coat in viroid but present in virus) and (presence of low molecular weight RNA in virus but absent in viroid)
- none of the above
- Read the following statements and select the option which correctly identifies the incorrect ones.
(i) Potato spindle tuber disease and Chrysanthemum stunt disease are caused by viroids.
(ii) T4 bacteriophage exhibits lytic cycle.
(iii) Retroviruses have two copies of ssRNA.
(iv) Interferons which prevent viral multiplication are glycolipid particles.- (ii) and (iii)
- (i) and (iv)
- (iii) only
- (iv) only
- Match the following:-
Column - I Column - II A Plant virus 1 Kuru disease B Animal virus 2 Potato spindle tuber
C Viroids
3 Polio
D Prions 4 Tobacco mosaic
- A-(iv), B-(iii), C-(ii) , D-(i)
- A-(i), B-(ii), C-(iii), D-(iv)
- A-(iii), B-(iv), C-(i), D-(ii)
- A-(ii), B-(iii), C-(iv) , D-(i)
- Which of the following phenomenon proves that viruses are living?
- They carry metabolic activity
- They carry anaerobic respiration
- They multiply in host cells
- They cause infection
- Select the mismatched pair :-
- Edward Jenner - Small poc vaccination
- Diener - Prions
- Louis Pasteur - Rabies vaccination
- W. Stanley - First to crystalise form
- Given is an electron microscopic structure of a T2 bacteriophage. Identify the unlabelled parts and select the correct option for P, Q, R, S and T.
- P - Head, Q - Collar, R- Sheath, S - Basal plate, T - Tail fibre
- P - Head, Q - Collar, R - Capsid,S - Tail, T - Tail fibre
- P -Capsid, Q - Sheath, R - Basal plate, S -Tail , T -Tail fibre
- P - Head , Q - Collar, R - Sheath, S - Capsomere, T - Tail fibre
- Which of the following statements are false about viruses?
I. Viruses are facultative parasites.
II. Viruses can multiply only when they are inside the living cells.
III. Viruses cannot pass bacterial proof filters.
IV. Viruses do not contain protein, DNA and RNA.
Code:-- I, II and III
- II, III and IV
- I, III and IV
- I, II, III and IV
- Select the pair that consists of viral diseases:-
- Mumps and small pox
- Herpes and influenza
- Pneumonia and syphilis
- Both (Mumps and small pox) and (Herpes and influenza)
- Host component of viral envelope is mostly:-
- lipids
- carbohydrates
- lipids and proteins
- lipids and carbohydrates
- In some viruses, RNA is present instead of DNA indicating that :-
- their nucleic acid must combine with host DNA before replication
- they cannot replicate
- there is no hereditary information
- RNA can transfer heredity material
- Which one of the following statements about viruses is correct?
- Viruses possess their own metabolic system.
- Viruses contain either DNA or RNA
- Viruses are facultative parasites.
- Viruses are readily killed by antibiotics.
- Which statement is incorrect about viruses ?
- Viruses are obligate parasites.
- Viruses can multiply only when they are inside the living cells.
- Viruses cannot pass through bacterial filters.
- Viruses are made up of protein and DNA or RNA (never both DNA and RNA)
- Which of the following statements are correct to describe viruses?
I. Simple and unicellular organisms.
II. Contains DNA or RNA and enclosed by protein coat.
III. Possesses own metabolic system and respond to stimuli.
IV. Maintain genetic continuity and undergo mutations.
The correct combination is:-- I and II
- II and IV
- II and III
- I and III
- Virus attacks a bacterium but neither multiplies nor the:-
- lysogeny
- adsorption
- assimilation
- viral stability
- Virion is :-
- nucleic acid of virus
- antiviral agent
- protein of virus
- completely assembled virus outside host
- Which one of the following option is correct ?
- A - Cell wall, B - Cell membrane, C - Heterocyst, D - DNA, E - Mucilagenous sheath
- A - Cell wall, B - Cell membrane, C - DNA, D - Heterocyst, E - Mucilagenous sheath
- A - Mucilagenous sheath, B - Cell membrane, C - DNA, D - Heterocyst, E - Cell wall
- A - Cell membrane, B - Cell wall, C - DNA, D - Heterocyst, E - Mucilagenous sheath
- ---------- give the name virus, which means venom or poisonous fluid.
Fill in the blank.- Pasteur
- M.W. Beijerinck
- Stanley
- Robert Hooke
- Select the incorrect statement :-
- Most plant viruses are RNA viruses.
- Bacteriophages possess ds DNA.
- Virus having an arthropod as vector is called as arbovirus.
- Prions possess only nucleoid and no proteins.
- Contagium vivum fluidum concept of virus was proposed by:-
- D.J. Ivanowsky
- Stanley
- M.W.Beijerinck
- Robert Hooke
- Analyse the following statements and identify the correct option given below.
I. Viruses that infects plants have single-stranded RNA and viruses that infects animals have either single or double-stranded RNA or double stranded DNA.
II. Bacterial viruses or bacteriophage are usually single-stranded RNA viruses.
Codes:-- I is true, but II is false
- I is false, but II is true
- I and II are true
- I and II are false
- Study the following table carefully and select the correct option for 1, 2, 3 and 4:-
Characters Monera Protista Fungi Plantae Animalia Cell type 1 Eukaryotic Eukaryotic Eukaryotic Eukaryotic Cell wall 2 Present in some Present Present Absent Nuclear Membrane Absent Present Present Present 3 Body organisation Cellular Cellular 4 Tissue/organ Tissue/organ/organsystem - 1- Prokaryotic , 2- Absent, 3- Absent, 4- Unicellular
- 1 - Prokaryotic, 2 - Present, 3- Present, 4 - Multicellular
- 1 - Eukaryotic , 2 - Present, 3 - Present, 4 - Multicellular
- 1 - Eukaryotic, 2 - Absent, 3 - Absent ,4 - Unicellular
- Which of the following option is correct ?
I. Mycoplasma has no cell wall.
II. Mycoplasma is the smallest living organism.
III. Mycoplasma cannot survive without 02.
IV. Mycoplasma are pathogenic in animals and plants.
V. True sexuality is not found in bacteria.
VI. A sort of sexual reproduction occurs in bacterium by adopting a primitive DNA transfer from one bacterium to the other.
Choose the correct option:-- I, III, VI
- Only III
- I, II, IV, V, VI
- All correct
- Influenza virus has:-
- DNA
- RNA
- both DNA and RNA
- only proteins and no nucleic acids
- Which of the following group of diseases is caused by viruses?
- Mumps, smallpox, herpes, influenza
- AIDS, diabetes, herpes, tuberculosis
- Anthrax, cholera, tetanus, tuberculosis
- Cholera, tetanus, smallpox, influenza
- The latest view for the origin of viruses is:-
- they have arisen from nucleic acid and proteins found in primitive soup
- they arose from bacteria as a result of the loss of cell wall.ribosome, etc
- they arose from some bacteria, which had developed a nucleus only
- they are modified plasmids, which are infact, the fragments of the nucleic acids of the host