Theme 4 Homestasis In Land Plants Part 1 Flashcards
How was bigger and better wheat cultivated
By giving plants water nutrition fertilizer and space.
The green revolution happened through breeding plants, the yield increased
What is the disadvantage of growing the same crop?
Monoculture
If the type of crop has a defect all crops are gone
What is homeostasis
Regulating the internal environment to keep a stable state
Dynamic process that compensates/adjusts for changes in the internal and external environment
Includes metabolism
What is the difference in animal nutrition vs plant nutrition
Animals depend on others for essential things (eg. can’t make methionine)
Plants concentrated things that are in low concentration. (Ex, co2, minerals,etc.
What are the essential elements for plants
How many are there
Nucleic acids (N,P) and amino acids (N,S)
Need to function as enzyme cofactors (help with making things, Ca2+
Need stuff to play a role in photosynthesis (mg2+, Fe2+, Fe3+) or regulation of osmotic potential (K+)
17 essential elements
What are the essential elements for plants divided into
Macronutrients
Micronutrients
What are macronutrients and what are they called
They’re Essential in large amounts
C,H,O from air and water (not considered minerals, make up 90% of dry mass)
N,P,K,S,Ca,Mg are minerals (only available as ions in water from the soil, only way for plants to take in)
What are micronutrients and what are they called
Essential in smaller amounts
Cu2+, cl-, Ni2+
What are the limitations of nitrogen
It’s mostly in air (78%) so it’s limiting to the plants that need it in soil
Need to convert to ionic form before plant can take it up
Hard to use because it makes strong triple bond with itself, need specific enzymes to break down
Nitrogen cycle provides some nitrogen though
What is nitrogen fixation
Nitrogen fixing bacteria Makes atmospheric N2 available to the plant by converting to NH4+
What is bacterial ammonification
Nitrogen from decaying organic matter is broken down to NH4+
But plants prefer no3-
What is bacterial nitrification
When nh4+ get oxidized to No3- (nitrate)
Once plant takes up the nitrate to make is easier to pick up, it get converted back to nh4+
What is special about legumes
Their root nodules have symbiotic relationship with nitrogen fixing bacteria
So the nitrogen in atmosphere is taken as nh4 into the plant
Don’t need nitrogen fertilizer
What is the disadvantage of nitrogen fertilization’s
The extra nitrogen is converted to nitrous oxide (major green house gas) and it released into atmosphere
What did dr borlauge do
He used breeding techniques to turn wheat to a dwarf plant
This gave it a high yield and disease/pest resistance, since shorter they reponded to higher rates of nutrients
Didn’t fall over
Led the green revolution which triple wheat amount and rice
But more water is needed to support the plants since they use more chemical and make bad soil quality
Creating diff strains with resistance
