Free Objective Test 02 Practice Test - 11th and 12th 

Question 1

In plants, the primary growth is due to the activity of ________.

A.

Intercalary meristem

B.

Lateral meristem

C.

Apical meristem

D.

Cambium

SOLUTION

Solution : C

Primary growth in plants is due to apical meristems (root and shoot apical meristems)

Question 2

In plants, the primary growth is due to the activity of ________.

A.

Intercalary meristem

B.

Lateral meristem

C.

Apical meristem

D.

Cambium

SOLUTION

Solution : C

Primary growth in plants is due to apical meristems (root and shoot apical meristems)

Question 3

 Cork Cambium is 

A.

Primary and apical meristem

B.

Secondary and apical meristem

C.

Primary and lateral meristem

D.

Secondary and lateral meristem

SOLUTION

Solution : D

Cork cambium (phellogen) is a secondary and lateral meristem.

Question 4

 Cork Cambium is 

A.

Primary and apical meristem

B.

Secondary and apical meristem

C.

Primary and lateral meristem

D.

Secondary and lateral meristem

SOLUTION

Solution : D

Cork cambium (phellogen) is a secondary and lateral meristem.

Question 5

Coconut milk factor is a/an ______.

A.

Auxin

B.

Gibberellin

C.

Abscisic acid

D.

Cytokinin

SOLUTION

Solution : D

Coconut milk factor is a cytokinin. Kinetin does not occur naturally in plants. Search for natural substances with cytokinin-like activities led to the isolation of zeatin from corn-kernels and coconut milk.

Question 6

Coconut milk factor is a/an ______.

A.

Auxin

B.

Gibberellin

C.

Abscisic acid

D.

Cytokinin

SOLUTION

Solution : D

Coconut milk factor is a cytokinin. Kinetin does not occur naturally in plants. Search for natural substances with cytokinin-like activities led to the isolation of zeatin from corn-kernels and coconut milk.

Question 7

Genetic dwarfness in some plants may be solved by treatment with: 

A.

Ethylene

B.

Gibberellins

C.

Auxins

D.

Anti gibberellins

SOLUTION

Solution : B

Genetic dwarfism is solved  by the usage of gibberellins. Ethylene is a gaseous hormone, which induces ripening in unripe fruits. ABA cause ageing and abscission of leaves.

Question 8

In __ growth, following mitotic cell division only one daughter cell continues to divide, while the other differentiates and matures.

SOLUTION

Solution : The increase in growth per unit time is called growth rate. In arithmetic growth after mitotic cell division, one daughter cell continue to divide and the other cell differentiates and matures.

Question 9

Number of mitotic divisions required to produce 100 cells by arithmetic growth from single cell is

A. 100
B. 101
C. 99
D. 200

SOLUTION

Solution : C

In arithmetic growth, following mitotic cell division, only one daughter cell continues to divide while the other differentiates and matures. 
N =100, N = n+1

100 = n+1

n =99

Question 10

Growth in plants _______.

A. ceases after organ formation
B. is not influenced by the environment
C. is of the open form
D. is restricted to apices only

SOLUTION

Solution : C

In plants, new cells are always being added by the activity of meristems to the body. This is called open form of growth.

Question 11

Which process is not involved in the development of grain into a mature wheat plant?

A. Mitosis
B. Differentiation of cells
C. Increase in size of cells
D. Meiosis

SOLUTION

Solution : D

Meiosis occurs during the reproductive phase and not during the development of the grain. Mitosis in the cells of such root and shoot apical meristems leads to increase in the number of cells. The cells derived from root apical and shoot-apical meristems and cambium differentiate and mature to perform specific functions. This act leading to maturation is termed as differentiation. The plant cells grow in size by cell enlargement which in turn requires water. Turgidity of cells helps in extension growth.

Question 12

Which of the following is caused by gibberellins?

A. Bolting in cabbage
B. Morphogenesis in tobacco callus
C. Rapid divisions in carrot cells
D. Elongation of oat coleoptile

SOLUTION

Solution : A

Bolting (internode elongation) just prior to flowering in cabbage is a test for gibberellin. Gibberelin helps in stem elongation.

Question 13

Apical dominance means ______.

A. Suppression of growth of apical buds by the axillary buds
B. Suppression of growth of axillary buds by the presence of apical buds
C. Stimulation of a growth of apical buds by the removal of axillary buds
D. Inhibition of growth of axillary buds by the removal of axillary buds

SOLUTION

Solution : B

In most higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called apical dominance. 

Question 14

Coiling of garden pea tendrils around any support is an example of

A. Thigmotaxis
B. Thigmonasty
C. Thigmotropism
D. Thermotaxis

SOLUTION

Solution : C

Thigmotropism is the movement due to contact with a foreign body. In twinners and lianas, there is less growth on the side of contact and more growth on the branch away from the contact. Coiling of garden pea tendrils around any support is an example of thigmotropism.

Question 15

A sleep movement in plants is a nastic response, that occurs daily in response to ____.

A. Lack of light
B. Light
C. Water
D. Both A and B

SOLUTION

Solution : D

Sleep movement is known as nastic response, this occurs daily in the response to some stimulus either day, night, temperature, pH, turgor pressure, etc.