Question Bank for 8th Class Science Microorganisms : Friend and Foe Microorganisms

1)

Bacteria have been grouped into four different types based on their shapes. Identify the different types and select the correct statement regarding it.

A)

Vibrio cholerae is an example of type S, which causes cholera.

B)

Lactobacillus is an example of type P, which helps in curdling of milk.

C)

Type R bacteria are rod-shaped and are called as bacilli bacteria.

D)

Streptococcus is an example of type Q bacteria that causes pneumonia.

View Solution

2)

Study the following table and select the correct option for P, Q, R and S.

Disease	Causative organism	Mode of transmission
Chicken-pox	Virus	P
Q	Bacterium	Water/Food
Malaria	R	Mosquito
S	Virus	Water

A)

P-Air/contact; Q-Cholera; R-Protozoan; S-Hepatitis B

B)

P-Mosquito; Q-Measles; R-Fungi; S-Polio

C)

P-Water; 0-Polio; R-Protozoan; S-Hepatitis B

D)

P-Air; Q-Typhoid; R-Fungi; S-Measles

View Solution

3)

Refer to the given diseases.

(i) Athlete's foot	(ii) Amoebic dysentery
(iii) Polio	(iv) Cholera
(v) Malaria	(vi) Measles
(vii) Pyorrhea	(viii) Ringworm
(ix) Typhoid	(x) Tuberculosis

Select the option which correctly identifies bacterial diseases (P), viral diseases (Q), protozoan diseases (R) and fungal diseases (S).

A)

P	Q	R	S
(iii), (iv), (v)	(ix), (x)	(i), (ii), (v)	(vii), (viii)

B)

P	Q	R	S
(iii), (vi), (x)	(iv), (ix)	(ii), (v), (viii)	(i), (vii)

C)

P	Q	R	S
(iv), (vii), (ix), (x)	(iii), (vi)	(ii), (v)	(i), (viii)

D)

P	Q	R	S
(iv), (vi), (x)	(iii), (ix)	(ii), (v), (vii)	(i), (viii)

View Solution

4)

Match different organisms in column I with their related characteristics in column II and select the correct option from the codes given below.

Column I		Column II
(a)	Entamoeba histolytica	(i)	A brown alga which is a rich source of iodine
(b)	Bacteriophage	(ii)	A protozoan that causes disease in human beings by living in the large intestine of humans
(c)	Penicillium	(iii)	A virus which infects a bacterial cell.
(d)	Fucus	(iv)	A fungus used to obtain antibiotic.

A)

(a) - (ii), (b) - (iii), (c) - (iv), (d) - (i)

B)

(a) - (iii), (b) - (ii), (c) - (iv), (d) - (i)

C)

(a) - (ii), (b) - (i), (c) - (iii), (d) - (iv)

D)

(a) - (iv), (b) - (ii), (c) - (i), (d) - (iii)

View Solution

5)

Consider the following statements and select the option which correctly identifies true (T) and false (F) ones.

(i) Diatoms are marine algae which float in water due to the presence of light storage fats with silica.

(ii) AIDS virus kills WBC and reduces immunity of the body.

(iii) Escherichia coli is present in intestine of human where they help in digestion of food.

(iv) A virus always consists of double strands of DNA or RNA surrounded by protein coat.

A)

(i)	(ii)	(iii)	(iv)
T	F	T	F

B)

(i)	(ii)	(iii)	(iv)
T	T	T	F

C)

(i)	(ii)	(iii)	(iv)
T	T	F	F

D)

(i)	(ii)	(iii)	(iv)
T	F	T	T

View Solution

6)

Select the incorrect statement.

A)

Anthrax is a bacterial disease that affects humans and cattle.

B)

Rust of wheat is a fungal disease that spread by air.

C)

Citrus canker is a viral disease that affects citrus fruits.

D)

Yellow vein mosaic is a viral disease that affects bhindi.

View Solution

7)

A bacteria undergoes binary fission in every minute. This bacterium can fill up a cup in 1 hour. In how much time will the cup be half filled?

A)

30 minutes

B)

59 minutes

C)

20 minutes

D)

40 minutes

View Solution

8)

Study the given figures and select the correct statements regarding these.

(i) Organism P is a unicellular green alga.

(ii) Organism Q is a parasitic protozoan.

(iii) Organism Q causes diseases in human beings.

(iv) Both the organisms P and Q cannot synthesise their own food.

A)

(i) and (ii) only

B)

(ii), (iii) and (iv) only

C)

(i), (ii) and (iii) only

D)

(i), (ii), (iii) and (iv)

View Solution

9)

How many among the following are fungal diseases in plants?

Citrus canker, Late blight of potato, Mosaic disease of mustard, Downy mildew of grapes, Leaf curl of cotton, Rust of wheat, Tobacco mosaic disease, Loose smut of wheat, Leaf curl of tomato

A)

6

B)

7

C)

4

D)

5

View Solution

10)

Study the given correlation.

Heat treatment : Sterilisation : : Vaccination : X

Here, X refers to

A)

Pasteurisation

B)

Immunisation

C)

Fertilisation

D)

Inoculation.

View Solution

11)

Match column I with column II and select the correct option from the codes given below.

Column I	Column II
(a) Apple scab	(i) Blue green algae
(b) Flagellum	(ii) Xanthomonas campestris
(c) Nostoc	(iii) Spirogyra
(d) Tooth Paste	(iv) Fungus
(e) Multicellular	(v) Euglena

A)

(a)-(v), (b)-(iv), (c)-(ii), (d)-(i), (e)-(iii)

B)

(a)-(ii), (b)-(v), (c)-(i), (d)-(iii), (e)-(iv)

C)

(a)-(iv), (b)-(v), (c)-(i), (d)-(ii), (e)-(iii)

D)

(a)-(i), (b)-(ii), (c)-(iii), (d)-(iv), (e)-(v)

View Solution

12)

Refer to the given figure showing different steps regarding antibodies fighting against a disease.

Arrange them in a correct sequence.

A)

(ii) \[\to \] (i) \[\to \] (iii)

B)

(i) \[\to \] (ii) \[\to \] (iii)

C)

(i) \[\to \] (iii) \[\to \] (ii)

D)

(iii) \[\to \] (i) \[\to \] (ii)

View Solution

13)

Read the given passage and select the correct option for X and Y.

Microorganisms are used for the large scale production of alcohol, wine and acetic acid. X is used for commercial production of alcohol and wine. The process of conversion of sugar into alcohol is known as Y.

A)

X: Streptococcus; Y: Aerobic respiration

B)

X: Saccharomyces Y: Fermentation

C)

X: Lactobacillus; Y : Fermentation

D)

X: Saccharomyces; Y: Aerobic respiration

View Solution

14)

Match column I with column II and select the correct option from the codes given below. (There can be more than one match for column I.)

Column I	Column II
(a) Green algae	(i) Gelidium
(b) Red algae	(ii) Chlamydomonas
(c) Blue-green algae	(iii) Nostoc
(d) Brown algae	(iv) Polysiphonia
	(v) Ulothrix
	(vi) Anabaena
	(vii) Sargassum
	(viii) Fucus

A)

(a)-(ii, v),

(b)-(i, vi),

(c)-(iii, iv),

(d)-(vii, viii)

B)

(a)-(ii, v),

(b)-(i, iv),

(c)-(iii, vi),

(d)-(vii, viii)

C)

(a)-(ii, vii),

(b)-(i, iv),

(c)-(iii, vi),

(d)-(v, viii)

D)

(a)-(ii, v),

(b)-(iii, iv),

(c)-(i, vi),

(d)-(vii, viii)

View Solution

15)

Identify the given microorganism and select the incorrect statement regarding it.

A)

It is a saprophyte commonly called as black bread mould.

B)

It reproduces by means of spores.

C)

It results in the spoilage of food materials.

D)

It is a parasitic fungus that causes various diseases in plants, animals and humans.

View Solution

16)

Refer to the given passage.

The mosquito P is a carrier of virus that spreads a disease Q. Another mosquito R is a carrier of protozoan S that spreads a disease called T.

Select the option which correctly identifies P, Q, R, S and T.

A)

P-Aedes, Q-Dengue, R-Anopheles, S-Plasmodium, T-Malaria

B)

P-Tse tse fly, Q-Dengue, R-Anopheles, S-Plasmodium, T-Malaria

C)

P-Aedes, Q-Dengue, R-Tse tse fly, S-Entamoeba, T-Amoebic dysentery

D)

P-Tse tse fly, Q-Dengue, R-Aedes, S-Entamoeba, T-Amoebic dysentery

View Solution

17)

Refer to the given figures P, Q, R and S.

Which of the following statements are correct regarding them?

(i) P is the mould from which penicillin is made.

(ii) R is considered as connecting link between plants and animals.

(iii) Q and S are parasites which live in the bodies of other organisms including human beings.

(iv) R and S bear chlorophyll and prepare food is presence of sunlight.

(v) S is colonial form of algae.

A)

(ii), (iv) and (v) only

B)

(i), (ii), (iv) and (v) only

C)

(i), (iii) and (iv) only

D)

(i), (ii), (iii), (iv) and (v)

View Solution

18)

Refer to the given outline of \[{{\text{N}}_{\text{2}}}\]cycle.

Identify X and Y and select the correct statement regarding this.

A)

In the process X, protein is converted into ammonia by the action of bacteria while in the process Y nitrates present in the decaying remains get converted into free nitrogen gas.

B)

In the process X, nitrates present in the soil get converted into free nitrogen gas while in the process Y, protein is converted into ammonia by the action of bacteria.

C)

Process X represents the conversion of ammonia into nitrates while process Y represents the conversion of nitrates into the free nitrogen gas.

D)

Process X represents the conversion of ammonia into nitrites while process Y represents the conversion of complex organic compound like proteins into ammonia.

View Solution

19)

Refer to the given experimental set up as shown in the given figure and select the correct option regarding it.