Agriculture Flashcards
What are contact action pesticides?
Kill plants by damaging their tissues. Contact insecticides kill insects that are sprayed directly or come into contact with the pesticide on the crop. (May be washed off by rain)
Describe hormone pesticides
Kill pests through their biochemical action, kill insects by increasing/starting natural processes. Low persistence and are quite specific.
What are examples of cultural pest control methods?
Companion crops, crop rotation, pest predator habitats, biological control, predator/pathogen species introduction
How can temperature be controlled in agriculture?
Smudge pots in apple orchards to prevent frost
Briefly outline what pheromone traps are
Used to indicate presence of pest so that pesticides may be sprayed. Can also be used to trap all of one gender of a species so that they can’t breed
Name three pros and one con of using antibiotics in agriculture
Increase livestock mass, prevent disease spread, treat infections in livestock
Although can lead to development of antibiotic resistant pathogens
Why is topography important in agriculture?
Terraced slopes
Contour ploughing to reduce soil erosion
Levelling undulating fields for eg rice padis
How can soil ph be controlled and what ph is optimal for agriculture?
Crushed limestone if too acidic
Sulphur powder if too alkaline
5.5-7 optimal
Define the term genetic manipulation
To control the inherited features of crop/livestock
Discuss the pros and cons of asexual reproduction/vegetative cloning
Produces genetically identical individuals
No genetic variation in offspring so no improvement in characteristics
Discuss the pros and cons of cloning in animals? 3 pros one con
Cloning not yet generally possible in animals
Potential advantages include replacement of animals with desirable features
Produce more individuals with the same desirable characteristics
Replace herds culled for disease control
How can cloning be useful in plants
Cultivation of cuttings or runners eg strawberries
Explain the term crossbreeding
Breeding between different varieties of crop or livestock breeds. Each parent has different desirable characteristics. Offspring may have a combination of the desired characteristics.
Name three improved breeding techniques involving genetic control
Artificial insemination, (AI)
Embryo transfer
F1 hybrids
Explain the process of artificial insemination
Semen sample inserted into a female. No need for animals to meet. Semen can be froze for later use
Explain the process of embryo transfer
Eggs are removed from female with desirable characteristics, then they are fertilised with semen. Embryos transferred into surrogate females. Original female can produce many offspring. Embryos can be stored frozen.
Explain the term F1 hybrids
True breeding varieties are homozygous for all genes
Offspring produced by breeding between two true breeding varieties
Characteristics inherited are often predictable
Genetic uniformity produces same characteristics and makes management easier-same growth rate, nutrient requirements etc
Explain Genetic engineering/transgenics
Genes are artificially transferred between organisms, often of different species. It produces characteristics that couldn’t be produced by natural breeding.
Name two examples of genetic engineering/transgenics
Golden rice in the Philippines
Increases vitamin A content
Genes transferred from daffodil and a bacterium.
Bt crops, genes transferred from a bacterium that releases a toxin. Bt crops are toxic to insect pests
Define the term productivity
A measure of yield per unit area of land
Define the term efficiency
A measure of yield per unit of input
What is food conversion ratio
The ratio of the mass of food needed to produce a given mass of animal biomass
