---
title: "Flowers, Fruits and Seeds"
book: "Primary & Middle School Biology"
subject: biology
language: en
chapter: 16
exercises: 10
source: https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds
---

# Chapter 16 — Flowers, Fruits and Seeds

In April the cherry tree is white with blossom; in June it hangs with cherries. Where did the [flowers](#def-g3-flowers-fruits-seeds-parts) go — and where did the [fruit](#prop-g3-flowers-fruits-seeds-transform) come from? The answer is one of the prettiest transformations in the living world: the [flower](#def-g3-flowers-fruits-seeds-parts) does not disappear, it *becomes* the [fruit](#prop-g3-flowers-fruits-seeds-transform).

## 16.1 Looking inside a flower

**Definition 16.1 (The parts of a flower).**

A *flower* is the part of the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) that will make the [seeds](#prop-g3-flowers-fruits-seeds-transform). From the outside in:

1. the *petals* , colored and scented, which attract visiting [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups) ;
2. the *stamens* , thin stalks dusted with *pollen* , a fine yellow powder;
3. in the very center, the *pistil* , a little flask; deep inside it lie the flower’s future [seeds](#prop-g3-flowers-fruits-seeds-transform) .

![Inside a flower, cut in half: petals around, pollen-bearing stamens, and the pistil in the center with the future seeds inside.](https://one-course.com/images/onecourse/chapters/biology-1/g3-flowers-fruits-seeds/fig-4d0b4a6184e4.svg)

*Inside a [flower](#def-g3-flowers-fruits-seeds-parts), cut in half: [petals](#def-g3-flowers-fruits-seeds-parts) around, pollen-bearing [stamens](#def-g3-flowers-fruits-seeds-parts), and the [pistil](#def-g3-flowers-fruits-seeds-parts) in the center with the future [seeds](#prop-g3-flowers-fruits-seeds-transform) inside.*

**Example 16.2 (Dissecting a tulip).**

Open a wilting tulip gently, [petal](#def-g3-flowers-fruits-seeds-parts) by [petal](#def-g3-flowers-fruits-seeds-parts). Inside stand the [stamens](#def-g3-flowers-fruits-seeds-parts) — brush one on your finger and it [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) yellow [pollen](#def-g3-flowers-fruits-seeds-parts) dust — and in the middle the fat green [pistil](#def-g3-flowers-fruits-seeds-parts). Slice the [pistil](#def-g3-flowers-fruits-seeds-parts) across (a grown-up’s knife-work) and there they are: rows of tiny pale future [seeds](#prop-g3-flowers-fruits-seeds-transform).

## 16.2 From flower to fruit

**Proposition 16.3 (Pollination, then transformation).**

For the transformation to start, [pollen](#def-g3-flowers-fruits-seeds-parts) must reach the [pistil](#def-g3-flowers-fruits-seeds-parts) — that step is *pollination*. Bees and other [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups) do most of the carrying, dusted with [pollen](#def-g3-flowers-fruits-seeds-parts) as they drink from [flower](#def-g3-flowers-fruits-seeds-parts) after [flower](#def-g3-flowers-fruits-seeds-parts); the wind does some too. After pollination:

- the [petals](#def-g3-flowers-fruits-seeds-parts) and [stamens](#def-g3-flowers-fruits-seeds-parts) , their work done, wither and fall;
- the [pistil](#def-g3-flowers-fruits-seeds-parts) swells and becomes the *fruit* ;
- the future [seeds](#prop-g3-flowers-fruits-seeds-transform) inside it become the *seeds* .

A [fruit](#prop-g3-flowers-fruits-seeds-transform) is a transformed [pistil](#def-g3-flowers-fruits-seeds-parts), and every true [fruit](#prop-g3-flowers-fruits-seeds-transform) carries [seeds](#prop-g3-flowers-fruits-seeds-transform).

**Proof.** *Admitted at this level.* ∎

**Example 16.4 (Watching one cherry happen).**

Follow a single cherry blossom. April: white [petals](#def-g3-flowers-fruits-seeds-parts), buzzing bees. May: [petals](#def-g3-flowers-fruits-seeds-parts) snowing down; where each [flower](#def-g3-flowers-fruits-seeds-parts) stood, a tiny green ball — the swelling [pistil](#def-g3-flowers-fruits-seeds-parts). June: the ball grown red and sweet — a cherry, with the stone (its [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed)) inside. The [flower](#def-g3-flowers-fruits-seeds-parts) did not fall; only its [petals](#def-g3-flowers-fruits-seeds-parts) did.

**Remark 16.5 (No bees, no cherries).**

Cherry growers welcome beekeepers’ hives into their orchards — without insect visits, most blossoms would stay unpollinated and fall without ever becoming [fruit](#prop-g3-flowers-fruits-seeds-transform). The bee is not stealing from the [flower](#def-g3-flowers-fruits-seeds-parts); [flower](#def-g3-flowers-fruits-seeds-parts) and bee feed each other: nectar for the bee, [pollen](#def-g3-flowers-fruits-seeds-parts) delivery for the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant).

![Pollination in progress: a bee deep in a cherry blossom, dusted with the pollen it will deliver to the next flower.](https://one-course.com/images/onecourse/chapters/biology-1/g3-flowers-fruits-seeds/img-b7a23dbac4ee.jpg)

*Pollination in progress: a bee deep in a cherry blossom, dusted with the [pollen](#def-g3-flowers-fruits-seeds-parts) it will deliver to the next [flower](#def-g3-flowers-fruits-seeds-parts).*

## 16.3 Fruit or not fruit?

**Method 16.6 (The seed test).**

To decide whether something from the greengrocer is a [fruit](#prop-g3-flowers-fruits-seeds-transform) in the biologist’s sense:

1. cut it open;
2. look for [seeds](#prop-g3-flowers-fruits-seeds-transform) (or a stone, which is a [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) in a hard [shell](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-covering) );
3. [seeds](#prop-g3-flowers-fruits-seeds-transform) inside — it grew from a [flower](#def-g3-flowers-fruits-seeds-parts) ’s [pistil](#def-g3-flowers-fruits-seeds-parts) : a [fruit](#prop-g3-flowers-fruits-seeds-transform) . No [seeds](#prop-g3-flowers-fruits-seeds-transform) anywhere — it is another part of the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) : [root](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) , [stem](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) or [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) .

**Example 16.7 (Surprises at the greengrocer’s).**

The [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) test springs surprises. Tomato: full of [seeds](#prop-g3-flowers-fruits-seeds-transform) — a [fruit](#prop-g3-flowers-fruits-seeds-transform), whatever the salad bowl says. Cucumber and courgette: [seeds](#prop-g3-flowers-fruits-seeds-transform) — [fruits](#prop-g3-flowers-fruits-seeds-transform). Green bean pod: [seeds](#prop-g3-flowers-fruits-seeds-transform) in a row — a [fruit](#prop-g3-flowers-fruits-seeds-transform). Carrot: no [seeds](#prop-g3-flowers-fruits-seeds-transform) — a [root](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) ([Exercise 3.10](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#exo-g1-plants-around-us-10) guessed it). Lettuce: no [seeds](#prop-g3-flowers-fruits-seeds-transform) — [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts). Potato: no [seeds](#prop-g3-flowers-fruits-seeds-transform) — a swollen underground [stem](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts).

**Remark 16.8 (Kitchen words, science words).**

In the kitchen, “[fruit](#prop-g3-flowers-fruits-seeds-transform)” means sweet and “vegetable” means savory — useful for planning dessert, useless for [biology](https://one-course.com/books/biology/1/en/chapter/1-living-or-not-living#def-g1-living-or-not-living). The biologist’s word follows the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) test. Both vocabularies are fine, as long as you know which one you are speaking.

## 16.4 Exercises

**Exercise 16.1 ★.**

Name the parts of a [flower](#def-g3-flowers-fruits-seeds-parts) from the outside in, with each part’s job.

**Solution of Exercise 16.1.**

[Petals](#def-g3-flowers-fruits-seeds-parts) (colored and scented, they attract [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups)); [stamens](#def-g3-flowers-fruits-seeds-parts) (thin stalks carrying [pollen](#def-g3-flowers-fruits-seeds-parts)); the [pistil](#def-g3-flowers-fruits-seeds-parts) in the center (the little flask holding the future [seeds](#prop-g3-flowers-fruits-seeds-transform)).

**Exercise 16.2 ★.**

What is [pollen](#def-g3-flowers-fruits-seeds-parts), and where is it found? What is pollination?

**Solution of Exercise 16.2.**

[Pollen](#def-g3-flowers-fruits-seeds-parts) is the fine yellow powder carried by the [stamens](#def-g3-flowers-fruits-seeds-parts). Pollination is [pollen](#def-g3-flowers-fruits-seeds-parts) reaching the [pistil](#def-g3-flowers-fruits-seeds-parts) — mostly delivered by visiting [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups), sometimes by the wind.

**Exercise 16.3 ★.**

After pollination, what becomes of: (a) the [petals](#def-g3-flowers-fruits-seeds-parts)? (b) the [pistil](#def-g3-flowers-fruits-seeds-parts)? (c) the future [seeds](#prop-g3-flowers-fruits-seeds-transform) inside it?

**Solution of Exercise 16.3.**

(a) They wither and fall. (b) It swells and becomes the [fruit](#prop-g3-flowers-fruits-seeds-transform). (c) They become the [seeds](#prop-g3-flowers-fruits-seeds-transform) inside the [fruit](#prop-g3-flowers-fruits-seeds-transform).

**Exercise 16.4 ★.**

Retell the story of one cherry, from white blossom to red [fruit](#prop-g3-flowers-fruits-seeds-transform), in three dated steps.

**Solution of Exercise 16.4.**

April: white blossom, bees visiting — pollination. May: [petals](#def-g3-flowers-fruits-seeds-parts) fall; the [pistil](#def-g3-flowers-fruits-seeds-parts) of each pollinated [flower](#def-g3-flowers-fruits-seeds-parts) swells into a tiny green ball. June: the ball has grown into a red, sweet cherry with the stone — the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) — inside.

**Exercise 16.5 ★.**

Why do cherry growers welcome beehives in the orchard?

**Solution of Exercise 16.5.**

Because without insect visits most blossoms are never pollinated, and an unpollinated [flower](#def-g3-flowers-fruits-seeds-parts) falls without becoming [fruit](#prop-g3-flowers-fruits-seeds-transform). The bees’ [pollen](#def-g3-flowers-fruits-seeds-parts) deliveries are what turn blossom into cherries.

**Exercise 16.6 ★.**

State the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) test, and apply it to the tomato and the carrot.

**Solution of Exercise 16.6.**

Cut it open and look for [seeds](#prop-g3-flowers-fruits-seeds-transform): [seeds](#prop-g3-flowers-fruits-seeds-transform) inside means it grew from a [pistil](#def-g3-flowers-fruits-seeds-parts) — a [fruit](#prop-g3-flowers-fruits-seeds-transform); none means another [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) part. The tomato is full of [seeds](#prop-g3-flowers-fruits-seeds-transform): a [fruit](#prop-g3-flowers-fruits-seeds-transform). The carrot has none: not a [fruit](#prop-g3-flowers-fruits-seeds-transform) but a [root](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts).

**Exercise 16.7 ★.**

[Fruit](#prop-g3-flowers-fruits-seeds-transform) or not, by the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) test: the cucumber, the lettuce, the green bean pod, the potato?

**Solution of Exercise 16.7.**

Cucumber: [seeds](#prop-g3-flowers-fruits-seeds-transform) — [fruit](#prop-g3-flowers-fruits-seeds-transform). Lettuce: no [seeds](#prop-g3-flowers-fruits-seeds-transform) — [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts), not a [fruit](#prop-g3-flowers-fruits-seeds-transform). Green bean pod: a row of [seeds](#prop-g3-flowers-fruits-seeds-transform) — [fruit](#prop-g3-flowers-fruits-seeds-transform). Potato: no [seeds](#prop-g3-flowers-fruits-seeds-transform) — a swollen underground [stem](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts), not a [fruit](#prop-g3-flowers-fruits-seeds-transform).

**Exercise 16.8 ★.**

Try it: at home, cut open three things from the kitchen and run the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) test on each. Which surprised you?

**Solution of Exercise 16.8.**

Open answer. The usual surprises: tomato, cucumber and bean pod turning out to be [fruits](#prop-g3-flowers-fruits-seeds-transform); the strawberry carrying its tiny [seeds](#prop-g3-flowers-fruits-seeds-transform) on the outside.

**Exercise 16.9 ★★.**

A late frost kills all the blossom on the plum tree in April. What will the June harvest be, and why? Use [Proposition 16.3](#prop-g3-flowers-fruits-seeds-transform).

**Solution of Exercise 16.9.**

Almost no plums. [Fruit](#prop-g3-flowers-fruits-seeds-transform) can only come from a pollinated [flower](#def-g3-flowers-fruits-seeds-parts)’s [pistil](#def-g3-flowers-fruits-seeds-parts); with the blossom dead in April, there is nothing left to transform, however fine the summer.

**Exercise 16.10 ★★.**

“The apple grows so that we have something nice to eat.” What is the apple really for, from the apple tree’s point of view? What lies at its core, and what could each one become? (Recall [Chapter 9](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#ch-g2-from-seed-to-plant).)

**Solution of Exercise 16.10.**

For the tree, the apple is a way of making and protecting [seeds](#prop-g3-flowers-fruits-seeds-transform). At its core lie the pips — [seeds](#prop-g3-flowers-fruits-seeds-transform) — and each pip, planted, could [germinate](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-germination) into a new apple tree. That we find the packaging delicious is our luck (and, for the tree, a way of getting its [seeds](#prop-g3-flowers-fruits-seeds-transform) carried far from home).