Unit 3 Flashcards
(42 cards)
What is food security
Your billeted to access food that is of quality and of quantity
Why do livestock produce less food per unit of area then crops
They lose 90% of energy is lost between trophic levels
What ways does light interact with leaves
It can be absorbed, reflected, transmitted
What are some examples of photosynthetic pigments
Chlorophyll A, chlorophyll B and Carotenoids
What is the absorption spectra
The wavelength of light absorbed by the pigment
What is the action spectra
Demonstrates which wavelengths can be used for photosynthesis
How is light captured in the chlorophyll
Absorb light energy excites the electrons within the pigment
Describe Photolysis
Light is captured in photosynthetic pigments, energy is harnessed to split water so that the hydrogen can be accepted by NADP and turned into NADPH, ATP is formed from ADP plus Pi and passed onto carbon fixation
Explain the Calvin cycle
It begins with RUBP with the addition of CO2 it is turned into RuBisCO which becomes 3PG and into G3P which can form glucose. The remaining is converted back into are you BP and the cycle continues. Energy is used and hydrogen is taken from NADPH. It is temperature dependent
Why are animals and plants bred for consumption purposes
To have higher food yields higher nutritional values and pest and disease resistance and the ability to thrive in particular environmental conditions
What are plant field trials used for
To compare performance. The selection of treatments to allow valid comparisons, replicates to take into account the variability within the sample, random treatments to eliminate bias
What does inbreeding produce
A uniform crop however inbreeding depression is the accumulation of homozygous recessive alleles that lower fitness
What happens when crossbreeding 2
inbred variants
Produces a population with improved characteristics known as F1 hybrids. Uniform heterozygous with increased vigour and yield
An example of recombinant DNA technology
BT toxin put into maize 
Explain annual weeds
One year life-cycle with rapid growth, short life-cycle, large number of seeds, long-term seed viability
Explain perennial weeds
They continue to return year by year, have storage organs and reproduce vegetatively
How do plant diseases work
They are caused by microorganisms such as fungi, bacteria, viruses.Often carried by insects, vectors.
How do you deal with weeds and disease
By ploughing, weeding and crop rotation
How do selective herbicides work
Overstimulating metabolism broadleaf weeds are targeted
How do systemic herbicides work
Through the vascular system, preventing regrowth
What are some examples of pests and how do you treat them, crops
Nematodes, mollusks and insects. Using herbicides, fungicides, insecticides, Molluskicides, nematocide
How do you systemic Pesticides work
Through the vascular system, kills pest upon consumption
When do you know to use pesticides
Using a disease forecast
What are some issues with using chemicals on crops
Toxicity to animal species, persistence in environment, accumulation/magnification, resistant past population
