Activity 11.7 Let us find out to compare different pollination strategies. Class 9
Activity 11.7 Let us find out to compare different pollination strategies. Class 9
Activity 11.7 Let us find out
Aim: To compare different pollination strategies based on pollen production, pollen to seed ratio comparison.
Table: Pollen production and seed formation data
| Pollination strategy | Approximate pollen grains released per flower | Estimated average number of seeds formed |
| Wind-pollinated grasses (e.g., maize, wheat) | 5.00,000 - 10,00.000 | 50 - 200 |
| Insect-pollinated plants (e.g., sunflower) | 20,000 - 40,000 | 800 - 1,000 |
Observation and Analysis:
Pollen to seed ratio comparison: Strategy Pollen produced Seeds formed Pollen:Seed ratio (approx.) Wind-pollinated (e.g., maize) ~ 7,50,000 (average) ~ 125 (average) 6,000: 1 Insect-pollinated (e.g., sunflower) -30,000 (average) ~ 900 (average) 33: 1
Question 1.
Compare and analyse the two strategies in terms of table. Class 9
- Pollen to seed ratio
- Efficiency of pollination and seed formation
Answer:
Comparison of the two strategies:
Pollen to seed ratio:
In some plants (like wind-pollinated), a very large number of pollen grains are produced but only a few seeds are formed → high pollen-to-seed ratio.
In others (like insect-pollinated), fewer pollen grains are produced and more seeds are formed → low pollen-to-seed ratio.
Efficiency of pollination and seed formation:
Wind pollination is less efficient because many pollen grains are wasted.
Insect pollination is more efficient because insects transfer pollen directly to flowers, leading to higher chances of fertilisation and more seed formation.
Question 2.
Explain why producing a very large number of pollen grains can still be an effective pollination strategy. Class 9
Answer:
Producing a very large number of pollen grains increases the chances that some of them will reach the chances that some of them will reach the stigma, especially in wind pollination, where the process is random. This ensures successful reproduction despite wastage.