The passage describes the sexual reproduction of a wind-pollinated grass flower.
Complete the passage by writing a suitable word in each blank space.
In wind-pollinated flowers, lightweight pollen grains are produced within the 1. _____________. This process involves a type of cell division called 2. _____________, which halves the chromosome number to produce haploid pollen. When mature, the pollen is released into the air and some of it is caught by the feathery 3. _____________ of another flower. The pollen grain germinates and grows a tube down through the 4. _____________ to the ovary. The male gamete then enters the 5. _____________ through a tiny pore called the micropyle. Here, the fusion of male and female nuclei, known as 6. _____________, takes place. After this, a seed is formed and the surrounding ovary wall develops into a 7. _____________.
Flowers have evolved different structural features depending on how they are pollinated.
State two differences between the stigmas of insect-pollinated flowers and those of wind-pollinated flowers.
Explain why the stigmas of wind-pollinated flowers are typically feathery and hang outside the flower, whereas those of insect-pollinated flowers are sticky and enclosed inside.
