Tag: plant growth and development

Questions Related to plant growth and development

Choose the correct answer from the alternatives given.
Elongation of a genetically dwarf plant is possible by the application of:

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. TAA

  2. GA3

  3. zeatin

  4. NAA

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Correct Option: B

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Spraying plants with a combination of auxins and gibberellins:

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. promotes formation of parthenocarpic fruit

  2. kills broad-leaved dicot plants

  3. prevents senescence

  4. promotes fruit ripening

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Correct Option: A
Explanation:

When sprayed on flowers, any of the plant hormones gibberellin, auxin and cytokinin could stimulate the development of parthenocarpic fruit.

So, the correct option is 'promotes the formation of parthenocarpic fruit'.

The hypothesis of algal origin of higher plants is based on which one of the following orders of Chiorophyta?

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Volvo ales

  2. Ultrichales

  3. Cladophorales

  4. Chaetophorals

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Correct Option: A

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If a long-day plant has a critical night length of 9 hours then which of the following 24-hour cycles would prevent flowering:

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. 16 hours light/8 hours dark

  2. 14 hours light/10 hours dark

  3. 4 hours light/8 hours dark/4 hours light/8 hours dark

  4. 8 hours light/8 hours dark/light flash/8 hours dark

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Correct Option: B
Explanation:

The critical photoperiod is the continuous duration of light which should not be exceeded in short day plants but should always be exceeded in long day plants. Here the critical night length for the long day plants are 9 hours which should more and the light phase should be smaller.

So, the correct option is '14 hours light/10 hours dark'.

Choose the correct answer from the alternatives given.
Bolting of floral shoots is triggered by a high concentration of:

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. auxin

  2. gibberellins

  3. cytokinins

  4. ethylene

Show answer
Correct Option: B
Explanation:

Gibberellins also promote bolting (internode elongation just prior to flowering) in beet, cabbages and many plants with rosette habit.

So, the correct option is 'gibberellins'.

Which one of the following does not act as a neurotransmitter?

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Cortisone

  2. Acetylcholine

  3. Dopamine

  4. Norepinephrine

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Correct Option: A
Explanation:

The chemicals releasing from a pre-synthetic neuron and interacting with specific receptors on post-synaptic neuron are called neurotransmitters. Cortisone is not a neurotransmitter.

Which of the following is true?

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Cytokinins helps in ripening of fruit.

  2. Gibberellins helps in ripening of fruit.

  3. Calcium carbide helps in ripening of fruit.

  4. Calcium carbonate helps in ripening of fruit.

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Correct Option: C
Explanation:

Calcium carbide is used for ripening fruit artificially in some countries. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is quite similar in reaction to the natural ripening agent ethylene.

Thus, the correct answer is option C.

The weight of fruit in a plant by the number of dominant alleles of a certain number of genes. If seven weight categories are noticed, how many gene sites would be involved?

biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Two

  2. Three

  3. Four

  4. Five

Show answer
Correct Option: A
Explanation:

Genes are the chromosomal part that carries genetic information from one generation to another. Each gene has a pair of two contrasting alleles which is responsible for the effect of the gene in dominant and recessive traits. If seven characters of weight are there each will have two sites in the gene which shows recessive and dominant characters.

So, the correct option is 'Two'.