Biology Today - February 2018

whereas pilot plant scale uses metallic container called

(iv). Microorganisms are added in (iv) in three ways :

(a) (v) growth system, (b) (vi) growth system and (vii)

growth system.

Assertion & Reason

In each of the following questions, a statement of Assertion (A)
is given and a corresponding statement of Reason (R) is given
just below it. Of the statements, mark the correct answer as :
(a) if both A and R are true and R is the correct explanation of A
(b) if both A and R are true but R is not the correct explanation
of A
(c) if A is true but R is false
(d) if both A and R are false.

14. Assertion : Pathogenic strains of bacteria often develop
    resistance to existing antibiotics.
    Reason : The resistance producing extra-chromosomal
    genes are present in plasmid and can pass from one
    bacterium to another.


15. Assertion : Antibiotics like cephalosporin and bacitracin
    inhibit bacterial growth by disrupting their wall synthesis.
    Reason : Antibiotics like polymyxin and nystatin inhibit
    bacterial growth by inhibiting their 50S ribosome function.


16. Assertion : A small part of activated sludge is used as
    inoculum in aeration tank.
    Reason : Activated sludge contains a number of
    aerobic heterotrophic microbes.


17. Assertion : Probiotic curd is supplemented with probiotic
    culture of %LILGREDFWHULXP.
    Reason : Previously %LILGREDFWHULXP were referred to as
    /DFWREDFLOOXVELILGXV.


18. Assertion : Smoother crops secrete certain chemcials
    which do not allow weeds to grow nearby.
    Reason : Alfalfa, sunflower, rye, etc., are some smoother
    crops.
    Figure Based Questions


19. Refer to the given figure and answer the following questions.

Floating

roof

A

D

B

C

(a) Identify the given figure.

(b) Identify A, B, C and D in the given figure.

(c) What is the use of C?

(d) What is the function of methanogenic bacteria in this

process?

20. Study the given flow chart of biogas formation and answer
    the following questions.

Proteins Fats Cellulose Hemicellulose

Decomposer

microbes

Biogas (C + D)

A

Methanogenic bacteria

B

Stage III

Organic acids

Stage II

Stage I

(a) Identify A, B, C and D in the given flow chart.

(b) What is the percentage of C and D in biogas?

(c) What is the another name of biogas? State few of its

uses.