movement of fluids in plants due to a pressure difference
ex. transpiration cohesion mechanism
cavitation
when the air bubble in xylem causes it to be useless
happens when its freezing
secondary growth creates new xylem
sink
where sucrose is being used (transport of phloem sap)
source
place where phloem sap is being made (transport of phloem sap)
phloem sap moves from ____ to ____
source to sink
pressure flow model
get better summary
significance of Jean Baptiste von Helmont's experiment
trees do not eat soil, most of their weight is from carbohydrates that come from CO2
nitrogen cycle is sped along by ____
prokaryotes (or bacteria)
four types of bacteria
ammonifying
nitrifying
denitrifying
nitrogen fixing
ammonifying bacteria
breaks down organic material which releases ammonia so that ammonium can be formed
nitrifying bacteria
uses ammonium to produce nitrate
denitrifying
takes some of the nitrate and converts it into nitrogen gas
nitrogen fixing
takes nitrogen gas from air, breaks tripple covalent bond to make ammonia
why cant eukaryotes break the tripple covalent bond in N2?
because enzyme nitrogenous cannot function in presence of oxygen
3 examples of legumes
peanuts, beans, alfalpha
root nodules
swelling on roots
bacteriods
vessicles in in the root nodules that contain one or more prokaryotes
rhizobium
type of bacteria that resides in vessicles of nodules of legumes
rhizobium is an exmaple of ____ and ____
mutualistic symbiosis and endosymbiosis
in angiosperms the ____ generation is dominant and the ____ generation is reduced
sporophyte
dominant
whorl
leaves at a particular place ona shoot
4 whorls of modified leaves
carpel-at base of plant, make up calyx
stamens-male part of plant
petals-makes up corolla
sepals-at base of flower, make up calyx
complete flower
has all 4 whorls
incomplete flower
doesn't have all 4 whorls
perfect flower
flower with stamen and carpel
imperfect flower
can be carpellate or staminate
monoecious
(one house) a single plant has both carpellate and staminate flowers on it
dioecious
(two houses) individuals contain only male parts while other individuals contain only female parts
how does pollen develope?
microsporocytes undergo meiosis to produce 4 microspores which undergo mitosis produce pollen grain
how does the ovule develope?
megasporocytes in the sporangium undergo meiosis to produces 4 megaspores. 3 die and the 1 that lives continues to grow and then divides 3 times to give you eight nuclei