Agriculture+-+Humans+and+Food+Plants

toc =Agriculture: Humans and Food Plants=

I. Miscellaneous

 * Humans have been **cultivating** plants for food for at least 2000 years
 * Angiosperms are the major group of plants used for food. Why?
 * Only about 3% of the Earth’s surface is available for food production
 * The world’s population is heavily influenced by how much food we can produce
 * Less than 2% of Canada’s population provides food for the whole country
 * Therefore farmers are having an increasingly hard time keeping up, while at the same time paying attention to environmental concerns (e.g. soil quality and pollution)

II. Food Plants

 * Everything we eat comes from plants
 * Fruits and animals are obviously plants, but, meat also has to consume plants before we can consume it
 * Edible plants are divided into 3 groups:
 * 1) underground (potatoes and carrots)
 * 2) above ground (lettuce)
 * 3) seeds and fruits of plants (apples and wheat)


 * **Legumes** are a special type of fruit-producing plant (e.g. beans, peas, soy)
 * Many plants can be eaten in their original form, but many are also processed (e.g. wheat into grain)

III. Increasing Plant Productivity

 * **Selective breeding**: analogy... humans differ a lot (e.g. height, weight, race, hair, shape, etc.)
 * Plants also differ a lot and farmers can isolate desired genes and make sure they are present in offspring through selective breeding
 * Wheat and corn are examples of crops that have been heavily selectively bred


 * **Hybridization**: selective breeding may cause one species of plant to develop frost resistance, whereas another species may develop a better crop yield
 * Hybridization **cross-pollinates** these species so that the two varieties are present in the offspring


 * **Cloning Techniques**: A small cutting is removed off the parent tree
 * The **cutting** is put in callus and a clone is able to grow
 * Another technique is **grafting**.

IV. Control of Agricultural Pests

 * We can have a better crop yield by improving crops or ensuring more crops survive


 * **Chemical Control**: pesticides, insecticides, fungicides herbicides, etc.
 * Although many farmers argue that chemical control is necessary it is:
 * 1) expensive
 * 2) destroys biodiversity
 * 3) destroys soil and surrounding environment


 * **Biological Control**: Using natural components to try and do the job of chemical control
 * e.g. Wasps were introduced to fight the alfalfa weevil
 * Problem: Biological controls don’t always have the intended results

V. Genetically Modified Organisms (GMOs)

 * With the rise of recombinant DNA technology, scientists can do years worth of selective breeding much faster. They can even add traits that would have been impossible to add using selective breeding.
 * Chemical controls (e.g. pesticide built-in to the plant so farmers don't have to spray pesticides on their crops) can be incorporated right into the GMO (and other good stuff)