Want to do a biology practical investigation, but don’t have access to a lab?
Do you have a passion for ecology and to discover the living world around you?
This project starter is full of ideas for hands-on practical investigations you can carry out.
Adaptation, evolution and survival can make great topics for a biology investigation. A good starting point is to have a close look at some plants, such as the ‘weeds’, which grow around your house or in the school grounds. Many of these have amazing survival strategies – which is why they are such successful weeds. These weeds offer valuable traits for crops and key medicinal plants, which may help the breeding of new varieties that can better resist climate change.
If you’re struggling for practical ideas for a project or investigation, sow some seeds and watch them grow. Make a note of any interesting observations. Then get into the habit of asking yourself some simple questions about your observations. It is quite likely that, sooner or later, one of your questions will turn into a good project.
The leaves of dandelions (Taraxacum officinale) sometimes lie flat and sometimes stand up.
What stimulus are the leaves responding to?
Where is it detected?
The vase life of some cut flowers seems to be affected by the presence of other flowers in the same vase, e.g. Forget-me-nots (Myosotis sp) wilt rapidly when they are put in the same vase as Narcissi (Narcissus sp).
Try to devise your own questions relating to this observation.
Seedlings respond to unidirectional light by bending towards the light source (positive phototropism).
What wavelength or wavelengths are they responding to?
Does the part of the seedling which responds also detect the unidirectional light?
Record the number and type of insects visiting different coloured flowers on sunny days.
When the petals are separated from the nectaries are the same insects still attracted to the petals?
Is it the colour of the flowers which is significant in attracting insects. What else could it be? Devise simple investigations to find out more.
The flowers of daisies (Bellis perennis) are sometimes open and sometimes closed.
What is it that stimulates the flowers to open and close?
Where is the stimulus detected, e.g. in the flowers themselves or elsewhere?
Do the flowers of other plants behave in the same way? Are they responding to the same stimulus?
Can the open flowers of laboratory grown plants, e.g. rapid-cycling brassicas, be made to close? (or inhibited from opening?)
Many small crucifer weeds are widespread and easy to culture in the lab. e.g. Shepherd’s Purse (Capsella bursa-pastoris), Hairy Bittercress (Cardamine hirsuta) and Thale Cress (Arabidopsis thaliana).
Drill a single hole about 5 mm in diameter in the bottom of a black film can. Insert a short wick of any suitable absorbent material. Transplant crucifer seedlings, one to a film can. Grow them in soil or compost. Place the film cans on capillary matting on a water reservoir made out of a margarine or ice cream carton. Follow the development of the plants through flowering to seed set. Growth may be more rapid under a light bank. A number of questions will arise, e.g:
What factors influence flowering, pollination mechanisms, tropic response of the flowering shoot, seed maturation, seed dispersal (especially in C. hirsuta)?
Grow some seedlings in bright light, shade and darkness. You will see some distinct differences which will raise questions which you can pursue. Suitable seedlings: Garden Pea (Pisum sativum), White Mustard (Sinapis alba), Salad Cress (Lepidium sativum), French Bean (Phaseolus vulgaris), etc.
Plants in the genus Euphorbia (the spurges) contain a white latex which is toxic and said to offer them protection from predation e.g. by herbivorous insects.
Petty Spurge (Euphorbia peplus) is a common weed on cultivated ground.
SAFETY NOTE: Euphorbia latex is toxic can cause skin burns and irritation. Take care to keep it off your skin and particular care to avoid getting it in your eyes.
Find a Euphorbia and look for evidence of predation. If you find it, try to find out what animal is causing the damage.
Smear Euphorbia latex onto other plants. Does it protect them from predation?
Learn a suitable technique for examining the stomata on leaf surfaces (e.g. nail varnish impressions).
Grow seedlings (e.g. in film cans) under controlled conditions.
Is the size and/or distribution of stomata influenced by the conditions under which the seedlings are grown?
What factors influence the behaviour of stomata?
Weeds compete with each other and with our crops and garden plants.
What sort of things do plants compete for when growing close together?
Make sure that you understand what the words bioassay and allelopathy mean. Use small seed such as Garden Cress (Lepidium sativum) as a bioassay to investigate the production of allelopathic compounds by other plants.
Why don’t seeds germinate inside ripe fruits such as tomatoes, apples, oranges, etc?
Use small inexpensive seed, e.g. Garden Cress (Lepidium sativum), as a bioassay to examine extracts from the tissues which surround the seeds in various ripe fruits. (Reference: Gill, J. (1982) ‘A study of germination inhibition in fruits’, Journal of Biological Education, 16 (3) pp 162 -163).
Study the way in which plants and animals are dependent on each other.
For example, adult hoverflies feed on nectar and pollen. Their larvae feed on aphids.
Do adult hoverflies lay their eggs on the same plants from which they get pollen and nectar?
What is it that attracts the adult hoverflies to a flower?