Describe the stages of pollen tube growth from the anther to the ovule in a flowering plant and explain why each stage is important.
Answer
The pollen tube grows in stages: 1. Germination on stigma initiates tube growth – enables pollen to reach ovule; 2. Tube elongation through style guided by chemical signals – ensures delivery of sperm; 3. Arrival at ovule triggers fusion with the egg and central cell – leads to fertilisation. Each stage is vital for successful fertilisation.
Step-by-step solution
- Pollen grain lands on stigma – the first contact triggers germination.
- Pollen tube emerges and grows through style, guided by female tissues – directs sperm to ovule.
- Pollen tube reaches ovule and releases two sperm – one fertilises the egg, the other the central cell.
- These events culminate in formation of zygote and endosperm.
- Each stage ensures accurate delivery and fertilisation.
Common mistake: Ignoring role of female tissues in guidance
Concept tested: Pollen tube guidance
Published · How this solution was prepared and checked
← All Sexual Reproduction in Flowering Plants questions