1) By looking at a plant externally can you tell whether a plant
is C3or C4 why & how?
morphological characters’ generally do not judge C3 and C4
plants. But some common habitats and characters’ can judge mum. C4
leaves are generally isobilateral but all isobilateral leaves are not C4
in natural & leaves of C3 plants are generally dorsiventral.
            Habitat: –        C4 plants are tropical plants
while C3 plants are found in all zones on earth.
        By looking at which internal
structure of a plant can you tell whether a plant is C3 or C4
            In case of C4 plants :-             In C4 plants a leaf has
kranz anatomy where the undifferentiated mesophyll occurs in concentrate layers
around vascular bundles & each vascular bundle is surrounded by a bundle
sheath of large sixed green cells. Starch grains do not occur in them.
            In case of C3 plants: –
Bundle sheath is not large, nor they contain chloroplasts. Mesophyll is often differentiated
into palisade & spongy parenchyma. They possess starch grass.
        Even though a very few cells in a
C4 plant carry out byways the tic calves’ pathway yet they are highly
productive. Can you discuss why?
            Calvin cycle is case of C4
plants occurs is bundle sheath. C4 plants have a high rate of
photosynthesis due to
        Rapid supply of CO2
from all mesophyll cells taking part in initial carbon dioxide fixation.
ii)         Absence of photorespiration due to absence
of photolysis in bundle sheath cells.
       Rapid windrow of photosysthates
from the bundle sheath cells as they lie occur the vascular bundles.
        Rubisco is an enzyme that acts
both as a carboxylase and oxygenize. Why do you think Rubio co carries out more
carboxylation in C4 plants?
            Rubisco functions as oxygenize only
when there is higher cone of oxygen & lower cone of CO2. Both
the conditions do not occurs in Rubisco containing bundle sheath cells of C4
plants. They do not have photolytic evolution of oxygen they receive a regular
supply of CO2 even when the stomata are closed.
             Rlubisco of C4 plants functions
only as carboxyl is.
5.         Suppose there were plants that had a
high concentration of chlorophyll a would it carry out photosynthesis? Then why
do plants have chlorophylls to and other accessory pigments?
            Chlorophyll a is essential for photosynthesis
because only its special molecules function as reaction centers (P700,
P688) Reaction centers convert light energy into chemical of
electron energy. Photosynthesis is absent is plants lacking chlorophyll a. /
            The importance of chlorophyll b
& other accessory pigment is (i) Absorption of light rays of different
wavelengths & transfer of this energy to reaction centre through resonance.
            ii) Protection of chlorophyll a
reaction centre from nascent oxygen & the other destructive radicals.
        Why is the color of leaf kept is
the dark frequently yellow or pale green? Which pigment do you think is more
            It will become yellow or pale green
when kept in dark because of the disintegration of chlorophylls careopnoids
which provide yellow color to the leaf are more stable.
        look at leaves of the same plant
on the shady side & compare it with the leaves on the sunny side orcorupane
the potted plants kept in the sun light with those in the shade. Which of them
has leaves that are darker green? Why?
            Shaded leaves are dark green due to
the reason
            i) Photo oxidation of chlorophyll is
bright light & its non oxidation is shaded region.
        Orientation of chloroplasts in
vertical files along the walls in strong light & their irregular
arrangement in shade.
        Figures show the effect of light
on the rate of photosynthesis Basic on the graph, answer the following question
            a) A which points (A, B or C) in the
curve are a light limiting factor.
            b) What could be the limiting
factor/s in the region A.
            c) What do C and D represent on the curve?
                        a) light is limiting in
A & 50% of B.
                        b) light
                        C-factors other than
light (like Co2) is limiting
                         D- light oration point under existing
conditions of other factors.
        Give comparison between the following:
                        a) C3 & C4
                        b) Cyclic &
non-cyclic ph to phosphor reach
                        c) Anatomy of leaf in C3
& C4 plants.
a) C3
i) Optimum
temperature for photosynthesis is 10-250 C
2) Serrations point
is reached at 10-700 of full sunlight
3) Photosynthesis
stops under conditions of water stress
4) Phospoglyciric
acid is 1st product
1) Optimum
temperature is 300-450 C
2) Serration point is
not reached even at full sunlight
3) It is not stopped.
4) Oxalo – acetic
acid is the first product.
Cyclic photo phosporyleation
1) It is performed by
photo system Independently.
ii) An external
source of electron is not required
iii) Synthesis only
i) It is performed by
collaboration of both photo system I & II
ii) The process
requires an external electron donor
iii) Synthesis ATP
& produce NADPIT 
C) Anatomy of leaf in C3
& C4 plants
C3  Plants
a) The leaves do not
possess Kranz & anatomy
b) Chlorophyll do not
have peripheral reticulum
c) Chloroplast are of
one type
d) Bundle neat cells
usually do not contain chloroplasts
C4 plants
a) They have
b) They have
c) They are two types
They possess
prominent chloroplasts.