- To understand that the flower is the reproductive centre of the plant.
- To identify the key parts of the flower involved in reproduction.
What You Need:
- A selection of different flowers, particularly those with a ‘classic’ structure, such as hibiscus or lilium.
- A pair of tweezers
- A scalpel or another small, sharp blade
- Any magnification tools, such as a magnifying glass, viewer or microscope will also be helpful.
What to do:
Use the tweezers (or very gently, your fingers) to remove the petals on one side of the flower.
Use the diagram below as a guide to identify the following parts on your flower:
Anther: The parts that produce pollen grains. Each pollen grain contains a male sex cell. There will be more than one anther on the flower.
Filament: The long strands that attach the anthers to the base of the flower.
(The anther and the filament together make up the Stamen, the male part of the flower).
Style: A long column standing up in the centre of the flower.
Stigma: The end of the style. It produces a sticky substance for capturing pollen.
Ovary: Located at the other end of the style from the stigma. The ovary contains female sex cells, or ovules.
(The Style, Stigma and Ovary together make up the Pistil, the female part of the flower).
Sepals: Special leaves around the base of the flower. The job is to wrap around and protect the flower bud.
Receptacle: The base of the flower where all parts are attached.
Peduncle: The stem of the flower.
How does fertilisation happen?
When pollen grains get stuck to the stigma, a ‘pollen tube’ begins to form – a tunnel that goes down the style to the ovary. The male sex cells travel down the pollen tube to the ovary, where they fertilise the ovules (female sex cells). The fertilised ovules then develop into seeds. A fruit forms around the seeds.
Colour Change Carnations
See how water is absorbed into a plant by changing carnations cool colours.Suitable for kids aged 4+ with parental supervision. Only adults should cut the flowers.You Need:
What to do:
- 6 x white carnation
- 6 x cups
- Food colouring (red, yellow, blue and green)
- Knife (to be used only by an adult)
- Fill each cup half full with water.
- Add about 30 drops of colouring into four different cups. One cup with blue colouring, another red, one yellow and one green. The more food colouring the better.
- Before placing any of the flowers in coloured water, have an adult make a fresh diagonal cut at the end of each stem. Ideally cut the flower stems underwater, to avoid any air getting into the stem tubes.
- Place one freshly cut carnation into each of the four cups of coloured water. Save the remaining two carnations for later. Which colour will be soaked up first? How long does it take? Do other white flowers work? li>
- Now its time to use the other two carnations. Have an adult cut the stem straight down the middle. Do not cut all the way to the flower head. Put each half of the stem into a cup of different coloured water (ie. One blue and one red, or one red and one clear). Will the colours mix? Remember to keep the stems wet at all times and to make fresh cuts.
- Check the flowers every couple of hours to see the progress of the colour. It may take as long as 2 days for the colour to work its way up to the white petals. Remember to examine the whole plant carefully including the stems, leaves, buds and petal to find every trace of colour.
Why is it so?Plants obtain (or drink) their water from the ground through their roots. The water travels up the stem of the plant into the leaves and flowers where it makes food.
Cut flowers no longer have their roots, but water still travels up the stem to the leaves and flowers through a process called capillary action. As water evaporates from the leaves, flowers and petals (transpiration) more water is pulled up the stem of the plant. Just like sucking on a straw. This happens because water can stick to itself (water cohesion) and the tubes in the plant stem are very small.
Adding colour allows you to see the movement of water through the plant easily and does not harm the plant in any way. Splitting the stem proves that the tiny tubes in the stem run all the way from the stem to the petals of the flowers.
Just like the coloured dyes in this experiment, some chemicals that pollute our waters can get into the soil and ground water and contaminate plants. Sadly, these pollutants can affect the health of the plant and its growth.
Recycled Seedling Paper Pots
Its easy to forget that making paper consumes trees and energy. These recycled paper-pots are not only fun to make, but they give new life to old catalogues and newspapers - reducing waste and helping the earth Raise a seed in your new eco-pot, then, when its time, plant the seedling pot and all in the garden no need to worry because the pots biodegradable and will break down quickly in the soil.Suitable for kids aged 5+ with parental supervisionCAUTIONThis experiment requires the use of hot water.You Need:
What to do:
- Cup, yoghurt container or bowl to mould your pot
- Newspaper, or other scrap, used un-wanted paper
- Large bowl or container to hold soaked paper
- Fine sieve
- Potato masher, or mortar and pestle
- Hot water
- Potting mix and seeds
- Tear scrap paper into very small pieces and soak in hot water for at least 3 hours. The longer the better, ideally leave the paper to soak overnight.
- Pour off excess water and mash up the paper with a potato masher, or a mortar and pestle - even a metal spoon if you dont have anything else. You want a pulpy, liquid consistency.
- Fill your pot-mould (cup or container) with the pulped-liquid paper using a spoon.
- Tip the pulped-paper out of the mould and into a sieve. Press as much water out of the paper-mush as possible.
- Put the drained paper back into the pot-mould, and use your fingers to press the paper into the sides of the mould and hollow out the centre. Youre making the shape of your final pot.
- Place the mould on a window sill or other sunny place so your paper pot can dry. It about a week youll have a finished paper seedling pot.
- Fill the pot with potting mix and plant some seeds. In time, plant your seedling and pot in the garden. The post will eventually decompose.
Why is it so?What else can you make out of recycled paper? Its a fun, environmentally friendly craft material. Did you know? More than 1 billion tress are cut down each year just to make disposable diapers! So recycling efforts count.