Each part of a flower has a job in reproduction. The anther makes pollen, the stigma receives it, and the ovary holds the ovules that become seeds.
This lesson opens flowering-plant reproduction. The next is comparing pollination mechanisms.
What does each part do?
| Part | Role | Leads to |
|---|---|---|
| Sepal | Protects the flower in bud | Opening of the flower |
| Petal | Attracts pollinators in insect-pollinated flowers | Pollination |
| Anther | Produces pollen grains | Pollen released |
| Filament | Holds the anther up | Pollen exposed |
| Stigma | Receives pollen | Pollen tube growth |
| Style | Supports the stigma, and the pollen tube grows through it | Tube reaches ovary |
| Ovary | Contains the ovules | Becomes the fruit |
| Ovule | Contains the egg cell | Becomes the seed |
Learn each role together with the next stage. A part is easier to recall when you know what it leads to.
Worked example: a missing part
An original question: a flower has its anthers removed before they open. What is the effect on the plant’s ability to reproduce?
- The anther produces pollen.
- Without anthers, the flower makes no pollen of its own.
- So this flower cannot pollinate itself or another flower.
- However, its stigma and ovary are intact, so it could still receive pollen from another flower.
The answer separates the male and female roles. The flower loses its male function but can still act as the female parent.
The mistake that costs marks
The common error is to say the ovary produces pollen, or that the anther contains the egg cell. Male and female parts make different things.
| Part | Wrong | Right |
|---|---|---|
| Anther | Holds the ovules | Produces pollen |
| Ovary | Produces pollen | Contains the ovules |
| Petal | Produces seeds | Attracts pollinators |
How do you write a role answer?
State the role in a short sentence, then link to the next stage. “The stigma receives pollen grains, which then grow a pollen tube down the style.”
Check yourself
A flower’s stigma is cut off before pollination. Predict the effect and give one reason.
Answer
Pollination cannot happen normally, because the stigma is the part that receives the pollen grains. Without it, pollen cannot attach and grow a tube, so fertilisation and seed formation are unlikely.
The anthers may still produce pollen, so the flower could still act as the male parent for other flowers.
What to study next
Go on to comparing pollination mechanisms. The biological data interpretation trainer has more structure questions, and the mistake log is a place to note mixed-up parts.
If you want a teacher to quiz you on what fails when a part is missing, see online one-to-one Biology tuition.