botany msc

2. 1. INTRODUCTION
2. TYPES OF BIOGEOCHEMICAL CYCLE
3. GASEOUS CYCLE
4. REFERENCES
(a) GASEOUS CYCLE
(b) SEDIMENTARY CYCLES
(a) CARBON CYCLE
(b) NITROGEN CYCLE

3. INTRODUCTION
BIO = “life”
GEO = “earth”
CHEMICAL = “elements”

4. :– The term gaseous cycle refers to the transformation
of gases between various biogeochemical reservoirs; Hydrosphere,
Atmosphere & iosphere
a)
b)
c)
d)

5. transportation of the matter through the ground to water.

6. Carbon moves from the atmosphere to plants.
Carbon moves from plants to animals.
Carbon moves from plants and animals to the ground.
Carbon moves from fossil fuels to the atmosphere when fuels are
burned.

7. Atmospheric CO2
Plants convert CO2 into carbohydrate
by the process of Photosynthesis.
Herbivores Death
Carnivores
Apex consumers
6CO2 + 6H2O + energy C6H12O6 + 6O2
C6H12O6 + 6O2 6CO2 + 6H2O + energy

9. Nitrogen Cycle :-

11. 1.Nitrogen fixation – Atmospheric Nitrogen can not be
used by plants and animals directly.It need to get
converted into Nitrogen compound.
2. Nitrification – some nitrifying bacteria convert
ammonia into nitrite and nitrate because NH3 is highly
toxic for some organisms.
3. Assimilation – nitrogenous compounds is various
forms such as NO3, NO2, NH3, NH4 are used to
plant and animal protein.
4. Ammonification – Dead plants and animals or
their waste containing organism nitrogenous
compound which enter into the soil fungi or bacteria
convert it back to ammonia.

12. – In this process the denitrification bacteria breaks
the nitrate to use its oxygen in anaerobic condition thus the nitrate
again get converted into gaseous nitrogen.