Controlling Weeds Organically

I am studying for a GCSE in Agriculture and Horticulture. The study I have chosen is to investigate types of weeds and the best ways to control them organically in different areas of the garden. I have set up a trial looking at hand weeding, mulching and the use of black polythene. Have you any advice you can give?

Competition between weeds and crop plants

I want to do a practical investigation into how weeds and plants compete in a field. Can you give me some ideas for this?

Weeds and how they spread

How are weeds spread?

What makes a "good" or successful weed?

Weeds versus plants

What is the difference between a weed and a plant?

How is DNA arranged in a plant cell nucleus?

Is there a central - source repository of plant DNA?

What might happen to the functioning of an enzyme if the gene that codes for it was altered by a mutation?

RNA and DNA

How did the RNA world develop into the DNA world? Why does RNA have uracil and DNA thymine?

What is "epigenetics"?

What is epigenetics? I wondered whether allergies such as a gluten intolerance could be a result of epigenetics?

Using PCR with plants

What plants should I use to get the best results from PCR? ie. related and non-related species.

Genetics, DNA, plants and humans

How much DNA do plants share with humans? Over 99%?

Practical activities for teaching genetics

I am about to start teaching the Applications of Genetics module of the UCLES modular A level Biology Course. I wondered if you have any practical work ideas which you feel are particularly suitable for this module, bearing in mind that I only have about 12 weeks in which to deliver it.

Extracting DNA from fruit and vegetables

Antibacterial effect of rosemary

Does rosemary have an antibacterial effect? I am interested in doing a project looking at the antibacterial properties of herbs available in the garden.

Can you suggest some plants with antibacterial or antibiotic properties?

Antibiotics from garlic

I am interested in doing a project on the antibiotic properties of garlic.

Genetic modification of plants

In an explanation of genetic manipulation, a marker gene conferring antibiotic resistance is used. This is said to be so that only cells which are resitant to antobiotics survive after incubation with the antibiotic. Why do antibiotics kill the plant cells that do not have the marker gene? I thought antibiotics only killed bacterial cells.

Extracting antibiotics from lichens

How can I extract antibiotics from Lichens? I would like to do this for a project.

Oxygen production by plants

How much oxygen does a houseplant give off in a day?