food production Flashcards
Which term describes the loss of fertiliser chemicals as water moves through soil?
leaching
What effect can leached fertiliser have on fresh water?
increase the nutrient concentration of fresh water
What can cause algal blooms?
increase in the concentration of dissolved nutrients in a lake
Weeds compete with crop plants for nutrients, water and light. How can farmers reduce this competition for resources?
by using pesticides
A pesticide accumulates in the bodies of organisms in a food chain
In which organism will the highest concentration of the pesticide be found
the organism at the top of the food chain
What happens to the toxicity of a pesticide in the bodies of organisms at higher levels in a food chain?
the toxicity of a pesticide in the bodies of organisms increases
Which term describes an organism of one species that can be used to reduce the population size of another species?
a biological control agent.
Which chemical must be inserted into a crop plant to genetically modify it?
DNA.
what modified crop plant would reduce the need to give it large quantities of fertiliser?
GM crops
what does an increasing human population require
an increased food yield
state the purpose of nitrates in the synthesis of proteins in plants and animals
it is a component of all the different amino acids that are used to make proteins
state the purpose of using fertilisers and pesticides in agriculture
it combat pests and diseases, boost productivity, and improve crop quality,
how do GM crops reduce the use of fertiliser
Scientists have added genes that make them toxic to insects.
what is bio accumulation
occurs when toxins build up - or accumulate - in a food chain.
name and describe alternative ways to remove pests instead of using pesticides
Biological control
involves using one species or biological agent to control the population size of another species.
