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A researcher observes that the growth rate of a plant significantly increases after the application of a specific hormone. Further analysis reveals that this hormone promotes cell elongation primarily in the intercalary meristem. Which hormone is most likely responsible for this observed growth?
Auxin
Cytokinin
Ethylene
Gibberellin
A particular mutation affects the synthesis of expansins in a plant species. Which of the following growth-related processes will be most directly impacted by this mutation?
Cell division in the meristem
Nutrient uptake from the soil
Photosynthetic efficiency
Cell wall loosening and expansion
A plant exposed to unidirectional light exhibits phototropism. If the tip of the coleoptile is removed and replaced with a gelatin block, then illuminated from one side, which of the following will be observed?
The coleoptile will bend towards the light source.
The coleoptile will bend away from the light source.
The coleoptile will not bend towards the light source.
The coleoptile will exhibit random growth.
A seedling is placed horizontally on a rotating platform in the dark. Which of the following best describes the growth pattern of the seedling's root and shoot after a few days?
Both root and shoot will grow horizontally.
The root will grow upwards, and the shoot will grow downwards.
The root will grow downwards, and the shoot will grow upwards.
Both root and shoot will grow in a random direction.
Vernalisation is most effective when the cold treatment is applied to:
Mature, fully grown plants
Dry seeds
Germinating seeds or young seedlings
Flowers
If a short-day plant receives a brief flash of red light during its dark period, what is the likely outcome?
Flowering will be inhibited
Flowering will be promoted
No effect on flowering
Vegetative growth will be enhanced
Which of the following is NOT a commercial application of understanding photoperiodism?
Producing out-of-season flowers
Controlling the flowering time of crops
Developing uniform flowering in plants
Increasing the size of individual fruits
If a winter wheat variety is not exposed to cold temperatures, it will:
Flower earlier
Flower later
Likely not flower
Produce more seeds
Which plant group typically requires vernalisation for flowering?
Tropical annuals
Biennials
Perennials that flower throughout the year
Plants with short life cycles