Question

Chapter - control and coordination in living organisms.

MCQs :-

1) Which is the natural auxin?

(A) 2,4-D
(B) NAA
(C) IAA
(D) IPA

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2) The surface area of wings is increased in the burd by the help of :

(A) Pectoralis major
(B) Pectoralis minor
(C) Remiges
(D) Rectrices


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3) Cell division is promoted by:

(A) 2,4-D
(B) kinetin
(C) gibberelin
(D) abscissic acid

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4) Premature leaf fall is brought about by :

(A) IAA
(B) 2,4-D
(C) NAA
(D) GA3

Answer 1

Hi.

here is your answer.

1 ) The natural auxin is C - indole 3 Acetic acid i.e. IAA .

It helps in plants growth. like stem elongation.

2).C. Rimigis

3) B kinatin :- it promotes cell division in plants. but it does not occurs naturally in plants.

4) A. IAA

hope it helps you ☺

Answer 2

ANSWERS :

1 ) Which is the natural auxin?  

(A) 2,4-D

(B) NAA

(C) IAA

(D) IPA

OPTION ( C ) IAA

(i) IAA is also known as Indole - 3 acetic acid

(ii) IAA is the most common naturally occurring auxin present in plants

(iii) IAA promotes growth by cell elongation

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2 ) The surface area of wings is increased in the bird by the help of :

(A) Pectoralis major

(B) Pectoralis minor

(C) Remiges

(D) Rectrices

OPTION ( C )

(i) Remiges increase the surface area of wings

(ii) They are located on the wing's posterior side

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3 ) Cell division is promoted by:

(A) 2,4-D

(B) kinetin

(C) gibberelin

(D) abscissic acid

OPTION ( B )

(i) Kinetin is a compound present in plants

(ii) It is a plant hormone that promotes cell division

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4 ) Premature leaf fall is brought about by :

(A) IAA

(B) 2,4-D

(C) NAA

(D) GA3

OPTION ( A )

(i) IAA is the hormone that also promotes falling of leaves

(ii) IAA is also responsible for cell elongation and is an auxin

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Hope it helps !

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