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FAQS
Q1. What is photosynthesis and what are its raw materials?
Ans. Photosynthesis is an anabolic process that converts carbon
dioxide into organic compounds, especially sugars, using
the energy from sunlight. Water (H2O), carbon dioxide (CO2), sunlight
and
chlorophyll are the raw materials needed for photosynthesis.
Q2. What are the two important functions of a leaf?
Ans.
The two important functions of leaf are:1. Gaseous exchange &
2. Manufacturing of food through photosynthesis.
Q3. What is meant by water loss by a plant and what is it
called as?
Ans. Water loss by a plant means oozing of water vapours in the
form of invisible water vapours through aerial organs of
plants. This water loss mainly takes place through stomata
of the leaves. This process is called transpiration.
Q4. What are three important tissue systems of a typical leaf?
Ans. Leaf is comprised of three basic tissue systems, which
include
the dermal, vascular,
and ground tissue
systems. Epidermis constitutes the dermal tissue, veins
(Xylem and phloem) the vascular tissue and mesophyll
forms the ground tissue.
Q5. What is Chlorenchyma?
Ans. Chlorenchyma is a type of parenchyma that contains
abundant chloroplasts.
Q6. Define mesophyll?
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Ans. It is the middle part of leaf comprising of spongy and palisade
tissues.
Q7. What is role of water in photosynthesis?
Ans. Water is the donor of electrons and protons during the
process of light reactions of photosynthesis.
Q8 Which organ of a plant is associated with photosynthesis and
why?
Ans. The organ of a plant associated with photosynthesis
is leaf. The carbon dioxide which is the raw material of
the photosynthesis enters through stomata of leaf and is
reduced to sugars in leaves.
Q9. Which structures of a leaf are mainly associated with gaseous
exchange?
Ans. The structures of a leaf associated with gaseous exchange
are stomata
Q10.What is light reaction of photosynthesis?
Ans. It is a light dependent chemical process which generates
assimilatory power, i.e. ATP & NADPH + H+.
Q11.What regulates opening and closing of stomata?
Ans.The opening and closing of stomata is regulated by turgor
changes. During day time stomata gain water and become
turgid. The concave sides of guard cells move apart and
stomata opens. At night guard cells loose turgidity which
leads to closure of stomata.
Q12 What is assimilatory power of cell.?
Ans. Light reaction generates ATP and NADPH + H+ molecules
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during Electron Transport Chain. These two are required
during dark reaction of photosynthesis for assimilation
of carbon dioxide into sugars. Therefore ATP and NADPH
together constitutes assimilatory power of cell.
Q13.Which process converts light energy into chemical energy?
Ans. A metabolic process called photosynthesis converts light
energy into chemical energy. This energy remains locked
in bonds of sugar molecules. During respiration sugars get
oxidized and ATP molecules are generated.
Q14.How does water loss exerts cooling effect in plants.?
Ans. As plant continuously loose water during transpiration,
fresh water is being absorbed through roots. It circulates
throughout plant which lowers temperature of plant with
respect to outer atmosphere.
Q15Which type of transpiration accounts for maximum water
loss?
Ans. Stomatal transpiration accounts for upto 90% of water loss
and is maximum water loss through any plant organ.