Plant propagation lesson plan

Lesson plan

KS2 Science; living things and their habitats, evolution and interitance
Science; SCN 4-O2a, SCN 2-14a, SCN 4-14b

  • Estimated time: 60 minutes
  • Location: Outdoors & Indoors
  • School term: All year round
  • Key stage(s): KS2, KS4
  • Subject(s): Science

Learning objectives

  • To understand that sexual reproduction in plants produces seeds which grow into plants that are similar but not identical to the parent plant
  • To understand that asexual reproduction in plants produces clones which are genetically identical to the parent plant
  • To grow new plants from different parts of the parent plant

Key vocabulary

Sexual and asexual reproduction, dissect, flower, sepal, petal, stamen, carpel, seed, clone, propagation, cuttings

Introduction

Present images on a whiteboard of Dolly the sheep, a strawberry plant with runners, potato, daffodil, bacteria splitting in two, clone troopers from Star Wars and a Dr Who cloned character. What do all these images have in common?
Explain that although cloning is an imaginary recurring theme in science fiction, it really does occur naturally in plants. Plants can reproduce asexually (producing clones) or sexually (producing seeds). Cloning is less common in animals, although identical twins are human clones. Some animals can now be artificially cloned. In the lesson pupils will compare sexual and asexual reproduction in plants and make a clone.

Activities

Dissect a flower: Give each pupil a magnifying glass and flower. The biological function of a flower is to effect reproduction. Now take apart (dissect) the flower, sticking each part to a sticky strip. Explain the purpose of each bit of the flower (sepal, petal, stamen, carpel) and label them. When the strip is complete it can be preserved with a cover of 'sticky back plastic'. A seed is formed after pollination and when it germinates it will produce a plant similar, but not identical to the parents.

Make a clone: Many plants also produce asexually. Give examples of these such as a spider plant or strawberry - which occur naturally.  Emphasise these plants are genetically identical to the parent. Plant breeders can take advantage of this by taking 'cuttings' (taking a piece of a plant to make more). Plants are also selected for desirable characteristics in this way. Different types of cuttings can be taken at different times of the year such as hardwood in winter. Learn how to take soft woodsemi ripe and hardwood cuttings.

Top Banana: So why persist in reproducing sexually? Asexual reproduction seems a faster and more efficient way to reproduce. As a case study, the banana can be explained as an asexual clone produced from a propagation of a plant with no seeds. Give pupils a slice of banana to eat while you compare it to the image of a wild, seed packed banana on the whiteboard. The variety of bananas we eat however have little natural resistance to pests and diseases. Discuss the advantages and disadvantages of sexual and asexual reproduction. What can be done to save the banana (as we know it) from extinction?

Plenary

In groups, draw and label a simple picture of a plant to show all the ways in which a plant can reproduce. Include propagation techniques used by plant breeders.
Label which plants use sexual and asexual reproduction.
Present back as a group including the advantages and disadvantages of each method.

Essential background information

  • A cutting is a section of a plant that, when put into suitable soil or compost, will produce roots and grow into a new plant.
  • Propagation is the process of creating new plants from a variety of sources.
  • The function of a flower is to effect reproduction

Resources

  • Flowers, magnifying glasses, sticky strips (card with a strip of double sided tape), bananas, paper.
  • Plant material for cuttings, scissors/secateurs, plant pots, compost, labels, re-cycled plastic bags or plastic bottles (to create propagators).

Differentiation

Less able: Play a 'Pictionary' style game in pairs. Draw all the types of reproduction and propagation used by plants. Work against a timer.

More able: Introduce basic Mendelian genetics with probability in maths.

Assessment questions

  • What is the purpose of a flower?
  • Sexual reproduction results in the production of what in plants? How do these plants vary from the parent plants?
  • Asexual reproduction in plants produces______. How do these compare to the parent plant?
  • What are the advantages and disadvantages of sexual and asexual reproduction in plants?

We've won awards!

Winner of the Drum Marketing Awards 2017
Winner of the ERA 2017 awards
Winner of the Third Sector 2017 awards