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Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

The most efficient precursor of ethylene is 

  1. Adenine

  2. Thiocarbamate

  3. Zeation

  4. Methionine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Two pathways for biosynthesis of ethylene in higher plants have been postulated. One is associated with the breakdown of peroxidized linolenic acid and the other involves degradation of methionine. 
A chemical mechanism accounting for such enzymatic formation of ethylene has been described. On the basis of this information, scientist has proposed the following scheme for the biosynthesis of ethylene in plants:
methionine -> alpha-keto-gamma-methylthiobutyric acid -+ methional--> ethylene.
In order to test the proposed pathways, radioactive linolenic acid and the appropriate radioactive methionine analogs were fed to apple tissue. None of these suggested precursors of ethylene was converted to ethylene as effectively as was methionine.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Pineapple can be made to flower in off season by ............

  1. Ethylene / NAA

  2. Zeatin

  3. Short day

  4. Temperature
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethylene gas acts to retard flowering in most of the plants. Whereas, in the case of pineapple, it increases the flowering in off season. Ethylene gas is also found useful in ripening fruits, when sprayed on to it.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

A higher proportion of ethylene is found in ...............

  1. Ripe banana

  2. Green banana

  3. Green apple

  4. Fresh potato tuber
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethylene gas is a gaseous hormone which stimulates the transverse or isodiametric growth but retards the longitudinal. It is having a prominent ability to promote early ripening of fruits when sprayed on to it.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Plant hormone controlling fruit ripening is

  1. IAA

  2. GA

  3. Ethylene

  4. Kinetin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethylene is a gaseous plant hormone. It is also called as ripening hormone as it plays the important role in controlling the fruit ripening. During fruits ripening, the respiration rate in fruits is increased by ethylene. Due to increased respiration, complex carbohydrates are broken down into simpler sugars and cell wall becomes soft.

Thus, the correct answer is option C.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Which hormone is not translocated?

  1. Auxin

  2. Gibberellins

  3. ABA

  4. Cytokinin

  5. Ethylene
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Cytokinin is synthesized in the root and is translocated from roots to shoots via xylem. Auxin is synthesized in the stem tip and is translocated via parenchyma cells to different sites. Gibberellin is translocated via phloem and xylem. Abscisic acid is translocated through vascular tissue and activated diffusion. Ethylene is diffused through intracellular spaces throughout the plant as it is gaseous in nature.

Thus, the correct answer is option E.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

How many following statements are correct for ethylene ?


1) Ethylene breaks the seed and bud dormancy
2) Ethylene promotes rapid petiole elongation in deep water rise plant
3) Ethylene promotes root growth and root hair formation
4) Ethylene promotes female flowers in cucumbers

  1. 1

  2. 2

  3. 3

  4. 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethylene induces seed germination. It breaks seed and bud dormancy. So 1 is the right answer.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Choose the correct answer from the alternatives given.
When mature green tomatoes are put in a sealed plastic bag, they remain green for several days. But, if one or two ripe apples are kept alongwith green tomatoes in the sealed container, the tomatoes turn red within a few days. It may be due to the fact that ripe apples:

  1. produce ethylene which induces tomato ripening

  2. remove carbon dioxide which initiates fruit ripening

  3. absorb ethylene which induces tomato ripening

  4. absorb carbon dioxide released from green tomatoes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethylene is highly effective in fruit ripening. It enhances the respiration rate during ripening of the fruits. 

So, the correct option is 'produce ethylene which induces tomato ripening'.