K325 / 2027

Lesson 4 of 12 / Reproduction

Flower parts and their functions

Which structures produce pollen, receive it and contain the female gamete?

I can identify an insect-pollinated flower and connect its structures to their functions.

  • I can identify insect-flower structures and examine pollen.Syllabus

    Syllabus K325, Topic 13(i). Identify insect-flower structures and examine pollen.

  • I can explain flower-part functions.Syllabus

    Syllabus K325, Topic 13(j). Explain flower-part functions.

About 5 min

Make a guess. You are not marked.

In a flower, which part catches pollen?

  1. The anther, which is covered in pollen.
  2. The ovary, where the seeds form.
  3. The stigma, at the top of the carpel.
Show the answer

The stigma, at the top of the carpel.

The stigma receives pollen. The anther, on the stamen, is where pollen is made.

The key idea

Stamens produce pollen; a carpel receives pollen and contains ovules. Petals attract pollinators and sepals protect the bud.

Insect-pollinated flower section showing petals, sepals, stamens and carpelStigma receives pollenAntherStyleOvarySepalPollen enlarged
Each stamen has an anther supported by a filament. The anther produces pollen grains.

The schematics show typical patterns. Real flowers and pollen vary; practise recognising their structures in the photographs below.

Find the parts in a real flower

Move between three views to identify parts that an intact flower hides.

Find the petals, anthers and rounded stigma tips. Which parts could a visiting insect contact?

An orange Hibiscus flower with broad petals, many small yellow anthers along a central column, larger rounded stigma tips at its top, and an insect near the flower base.
Tap the image to see it full size. Image: VINYLBLAST. CC BY-SA 4.0. Wikimedia Commons thumbnail; no further edits.

Use a hand lens on fresh flowers and prepare and focus pollen slides in your practical lesson. Photographs support identification practice; viewing them does not complete that hands-on work.

Explanation

A typical insect-pollinated dicotyledonous flower has sepals, petals, stamens and carpels. Sepals form the outer protective layer around the developing bud. Petals are often conspicuous and can help attract insects.

Each stamen consists of a filament supporting an anther. The anther produces pollen grains, which contain the male reproductive cells. A pollen grain is not itself a complete male gamete nucleus.

A carpel consists of a stigma, style and ovary. The stigma receives pollen. The style connects it to the ovary and provides the route for pollen-tube growth. The ovary contains ovules, each containing a female gamete.

For specimen work, examine the whole flower first, then use a hand lens to locate small structures. Record what you observe, including numbers and positions; real flowers do not all match a perfectly symmetrical diagram.

For pollen observation in supervised practical work, place a little pollen from an anther on a slide in a drop of water, add a coverslip and begin at low microscope power. Record grain shape and visible surface features. The illustration here supports recognition; it does not replace handling specimens and using a microscope.

Step by step
  1. 1

    Locate the outer structures

    Find sepals and petals before looking for reproductive structures.

  2. 2

    Separate stamen and carpel

    Anthers belong to stamens; stigma, style and ovary belong to a carpel.

  3. 3

    Link each part to a job

    Produce pollen, receive pollen, guide the tube, or contain ovules.

Worked example

Anther or stigma?

A structure releases many small grains when gently tapped. Another has a receptive surface at the top of the carpel. Identify each and explain its role.

One way to explain it

The grain-producing structure is an anther, which produces pollen. The receptive structure is the stigma, where pollen lands during pollination.

Why this answer works
  • Use function as evidence for identification.
  • Do not confuse producing pollen with receiving it.

Watch out for this

A student says: "The ovary and the ovule are the same structure." What is wrong with this?

Show the answer

The ovary contains ovules. Fertilisation occurs inside an ovule, not throughout the whole ovary.

Check your understanding

Which structure-function pairing is correct?

  1. Sepal: produces male gamete nuclei; anther: holds the ovules
  2. Stigma: receives pollen; ovary: contains ovules
  3. Anther: contains the ovules
Show the answer

Stigma: receives pollen; ovary: contains ovules

These are parts of the carpel with different roles.

Quick recall

Card 1 of 3. Answer in your head, then check.

Which structures produce pollen, receive it and contain the female gamete?

You can return to this lesson any time.