Tag: sense organs in animals

Questions Related to sense organs in animals

Which of these programmes is used to conserve a species from extinction?

  1. Captive breeding

  2. Natural resources

  3. Sustainable use

  4. Edge effect


Correct Option: A
Explanation:

Captive breeding is the process of maintaining plants or animals in controlled environments, such as wildlife reserves, zoos, botanic gardens, and other conservation facilities. It is sometimes employed to help species that are being threatened by human activities. The activities which pose threat include habitat loss, fragmentation, over-hunting or fishing, pollution, predation, disease, and parasitism. The objective of many captive populations is to hold similar levels of genetic diversity to what is found in wild populations.

So, the correct answer is 'Captive breeding'.

Which one is connected with management of zoo in India?

  1. IUCN

  2. SSC

  3. CZA

  4. WZCS


Correct Option: C
Explanation:

A) IUCN stands for the International Union for Conservation of Nature and Natural Resources.

B) SSC stands for The Species Survival Commission.
C) CZA stands for  The Central Zoo Authority, which manages the zoos in India.
D) WZCS stands for The World Zoo Conservation Strategy.
So, the correct answer is 'CZA'.

White lions are getting extinct and can be protected by

  1. Test cross

  2. Reciprocal cross

  3. Back cross

  4. Triple cross


Correct Option: B
Explanation:

In a reciprocal cross, a male expressing the trait of interest will be crossed with a female not expressing the trait or vice versa. The method can be used for the protection of white lions from getting extinct as some white lions will be produced in the progeny. There are fewer than 12 White Lions in the wilds of their endemic habitat. The need for conserving white lions is extreme now.

So, the correct answer is 'Reciprocal cross'.

Match the following.

A. IAA (i) Herring sperm DNA
B. ABA (ii) Bolting
C. Ethylene (iii) Stomatal closure
D. GA (iv) Weed-free lawns
E. Cytokinins (v) Ripening of fruits
  1. A-(iv), B-(iii), C-(v), D-(ii), E-(i)

  2. A-(v), B-(iii), C-(iv), D-(ii), E-(i)

  3. A-(iv), B-(i), C-(iv), D-(iii), E-(ii)

  4. A-(v), B-(iii), C-(ii), D-(i), E-(iv)


Correct Option: A
Explanation:

IAA is an auxin but has potential role of herbicide and weedicide. ABA is stress inducing plant growth regular. It can induce closure of stomata, Ethylene on other hand increases climactic rate and hence used for fruit ripening, GA or gibberlic acid are known to cause bolting in crucifers. Cytokinins were first isolated from Herring sperm DNA.

Thus, the correct answer is 'A-(iv), B-(iii), C-(v), D-(ii), E-(i).'

Which of the following is a plant hormone?

  1. Insulin

  2. Thyroxin

  3. Oestrogen

  4. Cytokinin


Correct Option: D
Explanation:

Insulin is secreted by Islets of Langerhans of the pancreas and serves to lower the blood glucose level by stimulating the uptake of glucose by cells, specifically muscle cells, liver cells and adipose tissues cells. 

Thyroxine is a thyroid hormone which targets all tissues and stimulates metabolic rate, growth and development. 
Oestrogen is the female sex hormone secreted by developing follicles in the ovary. It serves to stimulate the growth of the uterus and the vagina, is necessary for egg maturation as well as for the development of the secondary sex characteristics in females. Thus, options A, B and C are incorrect as these hormones are animal hormones. 
Cytokinins are the plant growth hormones that regulate the cell division in root and shoot of the plant both in vivo and in-vitro.
So, the correct answer is 'Cytokinin' 

Which one is paired incorrectly?

  1. Auxin - Isolated from human urine

  2. Zeatin - Isolated from corn kernels and coconut milk

  3. Gibberellins - Isolated from fungus G. fujikori

  4. Abscisic acid - Isolated from ripened oranges


Correct Option: D
Explanation:

Kogl et al. (1931) isolated auxin from human urine called heteroauxin which was identified as indole-3-acetic acid (IAA).
Zeatin is a cytokinin-like substance isolated and crystallised by Letham (1963-65) from milky endosperm of corn (Zea mays). It also occurs in coconut milk.
Yabuta and Sumiki (1938) isolated a chemical substance from the cultural filtrate of fungus Gibberella fujikuroi in crystalline form and named it gibberellic acid.
Cousins (1910) found that ripe oranges produced a volatile substance that hastened ripening of unriped bananas nearby. With the help of gas chromatography, it was found that the ripening causing volatile substance was ethylene.
So, the correct answer is 'Abscisic acid - Isolated from ripened oranges'.

To speed up the malting process in brewing industry the growth hormone used is ____________.

  1. auxin

  2. gibberellin

  3. kinetin

  4. ethylene.


Correct Option: B
Explanation:

Gibberellins are used to speed up the malting process in brewing industry. They increase the yield of malt from barley grains.

Read the given statements and identify the plant hormones X, Y and Z.
(i) Hormone Y suppresses flowering in mango and also promotes rapid internode/petiole elongation in deep water rice plants and hence helping leaves or upper part of shoot to remain above water.
(ii) Hormone X promotes root growth and root hair formation.
(ii) Hormone Z inhibits the seed germination, increases the tolerance of plant to various stresses, play important role in seed development maturation and dormancy.

  1. Y-ABA, X-Auxin, Z-GA

  2. Y-$C _2H _4$, X-Auxin, Z-GA

  3. Y-Auxin, X-$C _2H _4$, Z-GA

  4. Y-GA, X-auxin, Z-ABA


Correct Option: D
Explanation:

i) Gibberilic Acid (GA) suppresses flowering in mango, GA$ _3$, it is applied periodically to mango plants in their 1-4 yrs of growth to inhibit flowering and promote vegetative growth. GA plays a role in internode elongation in submerged parts of the rice plant.

Auxin along with cytokinin promotes root growth and root hair formation.
ABA is a stress hormones, it protects the plant from unfavorable environmental conditions, by preventing seed germination (due to oxygen deficit, water stress etc).
So, the correct answer is 'Y-GA, X-auxin, Z-ABA'

Read the given statements and select the option that is/are incorrect ones.


(i) Cytokinin is primarily concerned with cell division.
(ii) $C _2H _4$ breaks seed and bud dormancy.
(iii) ABA stimulates the opening of stomata.
(iv) $C _2H _4$ initiates germination in peanut seeds, sprouting of potato tubers.
(v) ABA is synergistic to GA.

  1. (i), (ii) and (iv)

  2. (iii) and (ii)

  3. (iii) and (v)

  4. (iv) and (v)


Correct Option: C
Explanation:

ABA is regarded as the stress hormone or a growth inhibitor. In conditions of water stress ABA initiates closure of stomata to prevent water loss through transpiration. It is antagonistic to GA as the latter promotes seed germination,  while ABA prevents seed germination.

So, the correct answer is ' (iii) and (v)'

Match the plant hormones listed in column I with their major role listed in column II and select the corret option from the codes given below.

Column I Column II
(A) Auxin (i) Fruit ripening
(B) Cytokinin (ii) Phototropism
(C) Abscisic acid (iii) Suppression of cell division
(D) Ethylene (iv) Stomatal opening and closing
(v) Growth of lateral buds


  1. A - (v), B - (iii), C - (iv), D - (ii)

  2. A - (iii), B - (ii), C - (iv), D - (i)

  3. A - (ii), B - (v), C - (iv), D - (i)

  4. A - (ii), B - (iv), C - (v), D - (iii)


Correct Option: C
Explanation:

(A) Auxin - (ii) Phototropism

(B) Cytokinin - (v) Growth of lateral buds

(C) Abscisic acid - (iv) Stomatal opening and closing

(D) Ethylene - (i) Fruit ripening

So, the correct answer is 'A - (ii), B - (v), C - (iv), D - (i)'.