1

Question 1

Which country and what was the theme?2007

Answer 1

Melting Ice - A hot topic – London, England

Question 2

Which country and what was the theme?2022

Answer 2

Only one Earth – Sweden

Question 3

Which country and what was the theme?2004

Answer 3

Wanted! Seas and Oceans - Dead or alive?

Question 4

Which country and what was the theme?2011

Answer 4

Forests: Nature at your Service – New Delhi, India

Question 5

that rivers and total
living species contain comparable amounts of
freshwater.

Answer 5

true

Question 6

Journey of hydrogen in primitive earth

Answer 6

took about 400,000 years for the universe to cool down
enough for electrons to be captured in orbits around protons.
* And then the first atom, the hydrogen, formed, simply one
electron and one proton.

Question 7

how planets came into existence

Answer 7

Hydrogen and Oxygen with some energy,fused together to form Water.
* After formation of water, it turned to ice in the coldness
of space and mixed with other dust particles
when enough dust from multiple supernova explosions
collected over time in one spot, the gravitational pull of all this
matter began to coalesce and collapse into another generation of
stars.

The leftover dust from the star formation coalesced into planets,
planetesimals, asteroids and comets.

Question 8

Hypothesis- Origin of water on earth since water coalesced into planets, our planet
would have had all the water it has today from its early
beginning.?

Answer 8

no
Theia collided
with earth and essentially turned it into one
giant piece of molten rock. The heat of this
collision would have evaporated most of the
water on earth.While some of it probably remained
due to gravity, a lot of the water would
have spewed back out into space.

Question 9

then source of water was ?

Answer 9

most scientists
thought that the most likely water delivery candidates were comets. But in 2012, researchers found that the
chemical makeup of the water on Comets doesn’t fit with the chemical makeup of the water on Earth.

Question 9

snowflakes

Question 10

The source of Earth’s water is most likely
asteroids.

Answer 10

Asteroids had huge amounts of
water too, since they had not been exposed
to the heat of the sun for as long as they
have now.

• The isotope ratios of near-earth
  asteroids match almost perfectly
  with the isotope ratios in water that
  we find on Earth.

Question 10

role of temp and water in snowflake

Answer 10

The ultimate shape of a snowflake depends mainly on temperature and humidity (water
vapor availability):
* Temperature: Snowflakes are crystals of water ice. They form at a temperature at or below
the freezing point of water. Different freezing temperatures promote the growth of specific
facets on the forming crystal.
* Also, snow crystals experience temperature gradients on their journey toward the ground,
sometimes partially melting and re-freezing.
Because the process is complex, no two snowflakes are quite alike. However, snowflakes often look similar to each other when
they fall under the same conditions.
* Humidity: High humidity levels mean more water vapor is available for deposition,
influencing the rate of melting

Question 11

Formation of strong magnetic field

Answer 11

By 4.2 billion years ago, a
liquid core formed in the
center of the Earth.

• Convection within the liquid
  core created a strong magnetic
  field surrounding the Earth.
• This geomagnetic field shields
  the earth’s surface from
  cosmic rays.
• The early earth prevented
  sunlight from reaching the
  surface.

Question 11

Primitive life origin

Answer 11

Uranium ore in the geysers emitted
large amount of radiation which created a diverse range of materials (Hydrogen, Methane, Ammonia)
.

• Which then led to formation of building blocks of life, the amino acid, phosphoric acid, and Nucleobase
  .
• These molecules circulated between the geyser cave and surface and interactions made the molecules complex and led to the production of Proto
  -RNA encoding molecule
  .
• Proto-RNA combined with enzyme
  -like basis materials and formed ribosomes which can replicate themselves

Question 12

By 4.0 billion years ago, the mother continent had
disappeared, leaving life on the margins of a fragmented
landmass.

The subducted primordial continent descended toward

the core mantle boundary and led to melting of the core-
mantle boundary.

Which led to strengthening of the Earth’s magnetic field
which again created a better platform for life.

Question 13

The emergence of Photosynthesis

Answer 13

2.9 billion years ago
* Oxygen, unbound to any other material, can be
toxic to life because oxygen destroys the
reductive life-body.
The oxygen released crystalized into felsic iron
bearing oxide which reduced the iron content of
the ocean.
* But still, the ocean was 5 times as saline as it is
today.

Question 14

Mantle overturn - 2.7 billion years ago

Answer 14

When the earth cooled down, the old slabs of the
primordial crust rest at the bottom of the upper mantle,
fell into the lower mantle and meanwhile, numerous
mantle plumes ascended from the lower mantle to the
upper mantle.

• Mantle plumes pushed the basaltic crust upward and
  that generated landmass which allowed the shallow
  marine environment exposed to sunlight and
  nourishment of cyanobacteria.

Answer 15

A collision between the Milky Way and a nearby galaxy led to
the creation of many stars which later became supernova.

• They deteriorated the sun’s heliosphere and bombarded with
  Earth.The cosmic rays helped in generating cloud condensation nuclei and
  produced more clouds until the Earth was completely covered.
• The cloud cover prevented sunlight and hence Earth became a
  snowball Earth eventually. This created a mass extinction. But, some
  life survived beneath the water below the ice covered

Question 16

Calcium helped Microdictyon to have a hard scales to protect them
from other animals.

Answer 17

• Salt from the sea water was relocated to the land in the form of rock salt.
• Decrease in salinity further helped the ocean to be more livable.

Question 18

Compensation depth

Answer 18

: The depth at which the gross
photosynthetic carbon assimilation and the respiratory
carbon loss or net photosynthesis is zero

phytoplankton do not stay at the same depth all
the time

. So, the net and gross should be calculated
based on the daily integrated photosynthetic or
respiration rates

Question 19

Critical depth

Answer 19

Depth at which the integrated daily
photosynthesis rate is balanced with the integrated
daily respiration rate
.

If the phytoplankton should have

a net production

and cell

• growth, the mixed layer depth should be
  shallower than critical depth

Question 20

Gross production/photosynthesis:

Answer 20

The total photosynthesis

Question 21

New production:

Answer 21

The primary production that is supported by newly produced nitrogen; the NO3- that comes through nitrification or upwelling.

Question 22

Net production/photosynthesis:

Answer 22

The gross photosynthesis -
respiration

Question 23

Regenerated production:

Answer 23

The primary production that is
supported by regenerated nitrogen which are reduced forms
of N. NH4+ , Urea etc.

Question 24

Light and photosynthesis -P/I curve

Answer 24

With increasing light, photosynthesis increases linearly
(with a slope a) until it reaches where the photosynthesis
rate is equal to the respiration rate.

compensation irradiance (Ic).

Question 25

maximum Photosynthetic rate

Answer 25

P max

Question 26

If the irradiance increases further, than compensation point

Answer 26

the trend become
gradually non-linear and a point is reached where further
increases in irradiance do not result in increases in the
photosynthetic rate.

Question 27

photoinhibition

Answer 27

In some species, decrease in photosynthetic rate happens
at high irradiance is called photo inhibition.Under high light conditions, plants absorb more light energy than they can use in photosynthesis. This excess energy can generate reactive oxygen species (ROS), which can damage cellular components, including proteins, lipid

Question 28

compensation depth

Answer 28

The compensation depth is the depth in a water column where the rate of photosynthesis by phytoplankton or aquatic plants exactly matches the rate of respiration. At this depth, the amount of oxygen produced by photosynthesis is equal to the amount consumed by respiration, and the net production of oxygen or organic carbon is zero.

Question 29

can cleaner or clearer water affect carbon assimilation

Answer 29

Light Intensity: The primary factor influencing the compensation depth is the availability of light. In clearer waters, light penetrates deeper, resulting in a deeper compensation depth

Question 30

Above/below Compensation Depth

Answer 30

Aquatic plants and phytoplankton can thrive, as they produce more organic matter through photosynthesis than they consume through respiration, contributing to the oxygen levels and supporting higher trophic levels.

Below Compensation Depth: The environment becomes net heterotrophic, meaning more organic matter is consumed than produced, leading to lower oxygen levels

Question 31

why is compensation depth not very practical

Answer 31

phytoplankton do not stay at same depth all the time. So, the net and gross should be calculated based on the daily integrated photosynthetic or respiration rates. Gross photosynthesis must be calculated by integrating these rates over the entire depth range they traverse and throughout the day.
.

Question 32

net total production

Answer 32

The net primary production, which represents the actual biomass available for higher trophic levels after respiration losses, is given by the difference between gross photosynthesis and respiration, integrated over the day and depth.

Question 33

critical depth

Answer 33

The critical depth is the depth at which the total gross photosynthesis (carbon fixation) by phytoplankton in the water column above it equals the total respiration (carbon loss) in that same column. Below this depth, the water column cannot sustain a positive net primary production.

Question 34

When the mixed layer depth extends below critical depth algal growth is light limited
and hence, no net phytoplankton growth.

Answer 34

This is the depth in the ocean where the water is well-mixed due to wind, waves, and turbulence. In this layer, temperature, salinity, and other properties are relatively uniform, and phytoplankton are evenly distributed.

When the mixed layer depth (MLD) is shallower than the critical depth: Phytoplankton spend enough time in the well-lit surface layers, where they can photosynthesize more than they respire, leading to net growth.

When the mixed layer depth extends below the critical depth: Phytoplankton are mixed deeper into the ocean, where light is insufficient for photosynthesis, so they spend more time in darkness or dim light. This results in light limitation, and there is no net phytoplankton growth because respiration exceeds photosynthesis.

Question 35

net production and cell growth, in relation to mixed depth layer and critical depth

Answer 35

the mixed layer depth should be
shallower than critical depth (provided sufficient
nutrients)
.

Question 36

red fields ratio

Answer 36

C:N:P = 106:16:1 for a healthy phytoplankton cell
* A. C. Redfield described the elemental composition of the bulk of the particulate organic matter in the
oceans.
* C:N ratio is 6.6:1 - helps to determine the physiological status of the algae.
* When it is nitrogen limited algal cells die and C:N ratio increases.

Question 37

for high NO3

• concentrations in

the polar region.

Answer 37

Low primary production
(plants cant take up)and global circulation
is the reason

Question 38

Decrease of Sea Salinity

Answer 38

Salt from the sea water was relocated to the land in the form of rock salt.
* Decrease in salinity further helped the ocean to be more livable.

Question 39

Through three major ways life
evolved:

Answer 39

1. Mass extinction - Through geological processes eradication of
   species.
2. Stem evolution - Genetic
   mutations while continental drift
3. Crown evolution - Bio- diversification when continents
   collided.

Question 40

meso/macroplanktons

Answer 40

krill

Question 41

megaplankton

Answer 41

Jellyfish are mostly carnivore and feed on
larvae and small fish.

Question 42

sizes of plankton

Answer 42

femto pico nano micro meso macro mega

Question 43

Femto- and picoplankton

Answer 43

1 ml of seawater there will be 1 million bacteria cells and approximately 100 million (1 x
108)

Question 44

photons in phtosynthesis

Answer 44

6CO2 +6H2O +48 photons of light 6O2 + C6H12O6

Question 45

Net production/photosynthesis:

Answer 45

The gross photosynthesis -
respiration

Question 46

New production:

Answer 46

The primary production that is supported
by newly produced nitrogen; the NO3

• that comes through

nitrification or upwelling.

Question 47

Regenerated production:

Answer 47

The primary production that is
supported by regenerated nitrogen which are reduced forms
of N. NH4
+
, Urea etc.

Question 48

Iz = mean irradiance experienced by the algal cell at mixed layer depth

I0 = Surface irradiance

k = attenuation coefficient
z = depth of mixed layer

Answer 48

Iz = I0*e-kz
If the mean irradiance is greater than the Ic (compensation irradiance) for the cell, it
can grow in the surface mixed layer.

Question 49

describe the seasonal variation of mixed depth layer

Answer 49

During spring, the mixed layer depth
(MLD) is shallow. Further, the surface
light availability gets higher and the MLD
gets more shallower.

Question 50

comparison of the mixed layer depth (MLD) and the critical depth.

Answer 50

Starting in mid-April, the mixed layer shallows and stays closer to or above the critical depth, which likely provides more light to the phytoplankton in the mixed layer. This could lead to the phytoplankton bloom seen in late April and May.
Timing of Phytoplankton Blooms:

The bloom in phytoplankton seems to occur after the mixed layer depth remains consistently above or equal to the critical depth in late April. This is consistent with the Critical Depth Hypothesis, which states that phytoplankton growth is optimized when the MLD is above the critical depth, allowing for sufficient light for net growth.

Question 51

Thermal stratification oceans

Answer 51

Thermal stratification is absence of
vertical mixing which result in nutrient
poor surface waters.
* Polar regions are rich in nutrient but
limited by light.

Net PP of the global ocean range
between 40-50 Pg C year-1

Question 52

inorganic carbon
1)lithosphere
2)atmosphere
3)hydrosphere

Answer 52

1)Limestone
(Calcite)(CaCO3+
(dolomite)CaMg(C2)

2)Carbon
Dioxide

3)CO2(aqueous)
, Bicarbonate,
andCarbonate
carbonic acid in rain

4)bios-Carbonate in
calcareous
organisms
like mussels