KS3 · Biology

Flower structure

A weed in a pavement crack and a flower in a wedding bouquet look nothing alike — yet inside, both hide the same set of parts doing the same jobs.

Biology · Anatomy

Inside a flower

Showing 4 layers: Flower stalk, Petals, Female parts, Male parts (stamens)

Layers

Explore

tap a part — or switch a group off

Tap any part to find out what it does. Then switch a group off to see which parts belong together.

A simplified flower drawn from the side, showing its male parts, its female parts and its petals.

Male, female or neither?

Sort the parts

Pick a part, then choose where it belongs. Watch out for the one that looks important but isn’t a sex organ.

Still to sort

Male (0)

The stamen and the parts it is made of.

Where the line is: Male parts make pollen or hold up the part that does.

Female (0)

Everything from the stigma down to the ovules.

Where the line is: Female parts catch pollen, hold up the stigma, hold the ovules, or make the egg cells.

Neither (0)

Part of the flower, but not a sex organ.

Where the line is: Big and colourful doesn’t make a part male or female. Petals help by attracting pollinators, but they don’t make pollen and they don’t make eggs.

7 of 7 still to sort.

Predict, then check

So what are all these parts actually for? Here’s the big idea behind them.

A new plant grows from a seed made by two parent plants. How much of the new plant’s DNA came from each parent?

What do you really think?

Pollen, ovaries and eggs

A bee visits a flower and gets dusted with pollen from the anthers. At the next flower it visits, some of that pollen rubs off onto the stigma.

Which of these is closest to what you think right now?

Each pollen grain is a male gamete — a male sex cell.The ovary is the flower’s egg — it’s the female gamete.Flowers that look completely different must have different reproductive parts.Pollen grains carry the male gametes, and the ova are made by the ovules inside the ovary.

How sure are you?

I'm sureI think soI'm guessing

Each pollen grain is a male gamete — a male sex cell.

This is a common misconception

Close, but not quite. A pollen grain carries the male gametes — it’s the delivery package, not the gamete itself. Think of an envelope and the letter inside: the bee moves the envelope, and the gametes travel inside it.

The ovary is the flower’s egg — it’s the female gamete.

This is a common misconception

The ovary is a container, not an egg. It sits at the base of the female parts, and inside it are the ovules. It’s the ovules that produce the ova — the egg cells, which are the female gametes. Ovary holds ovules; ovules make ova.

Flowers that look completely different must have different reproductive parts.

This is a common misconception

Flowers can look wildly different, but they have the same reproductive organs: stamens (anther and filament) and the female parts (stigma, style, ovary and ovules). Learn the set once and you can go looking for it in flowers that look nothing like this one.

Pollen grains carry the male gametes, and the ova are made by the ovules inside the ovary.

This matches the evidence

Spot on. The pollen grain is the carrier of the male gametes, and on the female side the ovules, tucked inside the ovary, produce the ova. Keeping carrier, container and gamete separate is exactly the precision this topic needs.

Pollen carries the male gametes. Ovules make the ova. The ovary holds the ovules — it isn’t the egg.

Why it matters

Reason it through

Why should anyone — not just a gardener — care how flowering plants reproduce?

Link 1 of 4

First link · your turn

What does a flowering plant make when it reproduces?

Locked — reveal the link above first

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

A flower is a plant’s reproductive system — and it hides a male team and a female team in one organ.

What you need to know

The flower is a flowering plant’s reproductive system. It contains both the male and the female sex organs.
The male part is the stamen, made of the anther and the filament. The anther produces pollen; the filament is the stalk that holds the anther up.
The female parts are the stigma, style, ovary and ovules. The stigma collects pollen grains, the style holds up the stigma and leads down to the ovary at the base, and the ovules inside the ovary produce the ova.
Petals attract pollinators such as bees, which transport pollen. During pollination, pollen is deposited on the stigma.
Gametes are sex cells. Each carries half of the genetic information, as DNA packaged into chromosomes in its nucleus.

The big picture

The flower is a flowering plant’s reproductive system: it holds both the male and the female sex organs. The male part is the stamen — an anther, which produces pollen, on a filament that holds it up. The female parts are the stigma (collects pollen), the style (holds up the stigma and leads down to the ovary), the ovary at the base, and the ovules inside it, which produce the ova. Petals attract pollinators such as bees. Pollen grains carry the male gametes and the ova are the female gametes; each gamete carries half the DNA, so a new plant gets half from each parent.

Key points

1Pollen grains CARRY the male gametes — a pollen grain is not itself the gamete.

2The ovary is not the egg: it holds the ovules, and the ovules produce the ova (egg cells), the female gametes.

3Flowers that look very different still have the same reproductive organs.

4Two parent plants each give half of the DNA to form a seed — the first stage of the new plant, which grows to resemble both parents.

5Plants are producers, and all animals, humans included, depend on the food they provide. Most crops, such as fruit and vegetables, come from plants that reproduce using flowers.

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Worked example

Problem

A student is shown three unlabelled parts from a flower they have never seen before. Part X is where pollen grains are collected. Part Y holds the ovules. Part Z produces pollen. Name each part, and say whether it is male or female.

⚠ Watch out

Mixing up ovary, ovule and ovum. They sound alike, but they are three different things: the ovary holds the ovules, and the ovules produce the ova (egg cells).

🧠

Memory hook

STAMEN has “men” in it — that’s the male part. Then read the female parts from top to bottom: the Stigma catches, the Style holds up, the Ovary houses, the Ovules make the ova.

✓

Check yourself

Cover the page. Can you name the two parts of the stamen and the four female parts, give the job of each one, and say what petals are for?

Flashcards

(13)

What is the reproductive system of a flowering plant?

The flower. It contains both the male and the female sex organs.

Which two parts make up the stamen?

The anther and the filament. The stamen is the male part of the flower.

What does the anther do?

It produces pollen.

What does the filament do?

It is the stalk that holds the anther up.

What does the stigma do?

It collects pollen grains.

What does the style do?

It holds up the stigma and leads down to the ovary.

Where is the ovary, and what is inside it?

At the base of the female parts. The ovules are inside it.

What do the ovules produce?

The ova (egg cells) — the female gametes.

What do pollen grains carry?

The male gametes.

What is a gamete?

A sex cell. It carries half of the genetic information, as DNA in chromosomes in its nucleus.

What do petals do?

They attract pollinators, such as bees, which transport pollen.

How much of a new plant’s DNA comes from each parent?

Half from each — so the new plant resembles both parents.

Why do animals, including humans, depend on plants reproducing?

Plants are producers that make their own food, and all animals depend on the food plants provide.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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Sort the parts

Pollen, ovaries and eggs

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