Aim

To prepare a temporary mount of a leaf peel in order to show the stomata of a leaf
Principle/Theory
Plants are the primary producers. They carry out physiological processes such as
photosynthesis and respiration which requires a gas exchange between the tissues
of plants and the atmosphere. This process is carried out through tiny openings
located in leaves, known as stomata. Stomata are tiny openings or pores which are
commonly noticed being distributed on the epidermis of the leaves and also in young
stems. Typically, stomata are found on the lower surface of a dicot leaf and in a
monocot leaf, on both of its surfaces. Stomata carry out the function of regulating gas
exchange and wate r vapour between the leave s of the pl ant and the
atmosphere.Stomata are are girdled by two-kidney shaped cells known as guard
cells on either side of the stomata. The guard cells possess a thick inner wall and a
thin outer covering which control the closing and opening of the pores of stomata.
Turgidity of the guard cells causes the stomata to open while the flaccid nature of
the guard cells causes the stomata to close.
Materials Required
 A potted plant of Bryophyllum or Tradescantia
 Needles
 Forceps
 Watch glass
 Dropper
 Glass slides
 A brush
 Coverslips
 Blotting paper
 Safranin
 Compound microscope
 Glycerine
Procedure
 Pick a healthy leaf from the potted plant.
 Fold the leaf to gently pull the peel apart to separate a peeled section from the lower
surface of the leaf. Use the forceps to perform this step. Allow the peel to remain in
a watch glass holding water for some time.
 In the watch glass, stain the sample by adding some drops of safranin through a
dropper.
 Take the peel out after 2-3 minutes. Set it on a clear glass slide.
 Add a drop of glycerine on the peel. Put a clear coverslip over it gently using a needle.
 Excess glycerine and stain can be removed using blotting paper.
 Examine the slide first under a low-power and then under a high-power magnification
of a compound microscope.
Diagram

Observation
 Visible epidermal cells. The cells in their outline are irregular with no intercellular
spaces.
 Small openings, stomata are scattered through the epidermal cells.
 Guard cells are observed which have chloroplasts and nucleus.
 Guard cells are obse rved having a thin outer cove ring and a thick inne r
boundary(concave).
 Guard cells control the closing and opening of the stomata.
Conclusion
Epidermal cells are found containing stomata on the lower surfaces of the leaf.
Precautions
 Avoid folding the leaf too much. The peel should be snipped to a proper size
 The peel should always be placed at the centre of the slide and the slides should be
held from the sides.
 The peel should neither be overstained nor understained.
 A brush should be used to handle the peel, otherwise would damage cells.
 Glycerine should be used in order to prevent drying of the peel.
 Coverslip needs to be placed gently to avoid the entry of air bubbles.
 Blotting paper can be used to remove excess stain.
Aim
To experimentally demonstrate that carbon dioxide is released during the process of
respiration.
Principle/Theory
The process of respiration is biochemically carried out wherein food, glucose to be
precise, is oxidized and energy is released. In this experiment, gram seeds (moistened)
are used. The purpose of using these seeds is that they release carbon dioxide and
are respiring actively. The released carbon dioxide is consumed by the solution of
KOH.
Materials Required
 Soaked gram seeds
 U-shaped delivery tube
 Conical flask
 Blotting paper (moist) /cotton wool
 Thread
 Water
 Beaker
 Test tube
 Rubber cork with a single hole
 Freshly prepared KOH solution (20%)
 Vaseline
Procedure
 Germinate close to 25 seeds. This can be done by wrapping them in moist blotting
paper or cotton wool for around 3 to 4 days.
 Set up the germinated or sprouted seeds in the conical flask. Spray some water into
the flask to dampen the seeds.
 With the help of a thread, suspend the conical flask containing the test tube having
a freshly prepared 20% KOH solution.
 Use the rubber cork to seal the opening of the conical flask.
 One edge of the U-shaped glass delivery tube present in the conical flask should be
inserted through the hole in the rubber cork. The other edge should be placed into a
beaker that is saturated with water.
 All attachments of the set-up should be sealed. This can be done using vaseline to
create an air-tight environment.
 The initial water level present in the U-shaped delivery tube needs to be marked.
 Leave the experimental set-up uninterrupted for 1 to 2 hours. Observe the fluctuations
in the water level in the tube.
Diagram.

Observation
Careful observation after a certain period of time reveals that the water level in the
U-shaped delivery tube has risen in the beaker.
Conclusions
The rise in level water indicates that carbon dioxide is released as a result of
germinating gram seeds during the process of respiration in the conical flask. The
carbon dioxide that is released in the process is absorbed or consumed by the KOH
solution that is suspended in the test tube in the conical flask, creating a vacuum or
a void in the flask resulting in the upward water movement in the tube. Hence, the
water level in the tube changes.
Precautions
 The seeds that are to be germinated need to be moistened.
 Air-tight environment for all the connections in the experimental set-up.
 The KOH solution that is used needs to be freshly prepared.
 Care needs to be taken to ensure that one end of the delivery tube is placed in the
conical flask. The other edge is submerged in the water of the beaker.
 The tube that contains the KOH solution needs to be suspended carefully.
Aim
To study about (a) Binary Fission in amoeba and (b) Budding in yeast with the help of
prepared slides
Principle/Theory
Budding and binary fission are types of asexual reproduction observed in lower
organisms such as bacteria, unicellular protozoans and some other entities.
Binary fission
In this type of reproduction, the parent cell divides or is split into two daughter cells
through mitosis wherein each daughter cell develops into an adult. Amitosis is the
division of the nucleus.
Budding
It is a kind of asexual reproduction wherein a new organism develops from a bud or
an outgrowth due to the process of cell division at a particular site.
Materials Required
 Compound microscope.
 Permanent slides of budding in yeast and binary fission in amoeba.
Procedure
 Place the slide under a compound microscope.
 Focus the slide, first under low power and later under high power of the compound
microscope.
 Various stages of budding and binary fission can be carefully examined.
Diagrams
BINARY FISSION IN AMOEBA

BUDDING IN YEAST
Observation
(a) Binary fission in Amoeba.
 Initially, the pseudopodia are retrieved. The body of amoeba is coiled and becomes
round.
 Amitosis is observed, the division of the nucleus takes places which are followed by
splitting of cytoplasm.
 At the point of fission in the body of the amoeba, a constriction starts to develop.
 The constriction or furrow turns deeper resulting in the formation of two daughter
cells.
(b) Budding in yeast
 Protuberance or a tiny outgrowth is observed on the parent cell.
 Division of the nucleus is observed which is later seen in the bud.
 Repetitive budding leads to the formation of a chain of cells.
Conclusion
The prepared slides display asexual reproduction. One individual is involved to produce
a new offspring of its own kind.
Precautions
 Slides need to be aligned and focused accurately
 Sketch out your observation that is observed under a microscope
 The slides first need to be examined under a low-power magnification of the compound
microscope and then under high-power magnification.
Aim
To identify the different parts of an embryo of a dicot seed
Principle/Theory
The process of fertilization in plants leads to the formation of fruits which forms the
ripened ovary. The seed can be one or many which form the mature ovule.
A seed consists of the following parts:
 Hilum – It is a scar that is located on the seed coat, associated with the stalk of the
plant
 Seed coat – Forms the exterior covering of the plant, supplying with nourishment
and protection to the seed inside
 Endosperm – It is the tissue containing nutrients for the growth of the embryo
 Embryo – Several divisions of the zygote gives rise to this structure. Embryo consist
of the following parts:
 Radicle
 Plumule
 Cotyledons
On the basis of cotyledons in the seed, angiosperms can be classified into the following:
 Monocots
 Dicots
Germination:
Germination is the process wherein the micropyle present in one part of the hilum
takes up water. which under favorable conditions, such as suitable light, temperature,
air, etc, uses up for the seedlings to develop into tiny, immature embryonic plants
from the seed coats.
Germination involves the following steps:
 Seeds swell, plumules develop into shoots.
 From the radicle of the seeds, the roots arise.
 Formation of cotyledons(one in monocots and two in dicots)
Materials Required
 Seeds of red kidney bean/gram
 Forceps
 Magnifying glass
 Cloth
 Petri dish
 Water
Procedure
 Soak a few seeds overnight.
 Next morning, drain the excess water out.
 Now wrap the seeds in a clean and a moist cloth for a day, allow it to dry.
 Next, carefully peel the seed coat.
 With the help of forceps, dissect the seed so as to get two equal halves.
 Examine with the help of a magnifying glass. Carefully identify and locate different
parts of the seed.
 Sketch out the interior of the seed you examined labelling all the parts as shown in
the diagram.
Diagram

Observation
 The bean seed resembles the shape of a kidney. It has a convex and a concave side.
 A scar known as the hilum is observed on the slightly darker side of the concave side.
 A tiny pore known as the micropyle is located just adjacent to the hilum.
 The seed is enclosed by a seed coat.
 The embryo possesses two distinct and large cotyledons that resemble the shape of a
kidney and are white in color.
 Lateral attachment of the cotyledons to the curved embryonal axis is observed.
 Radicle is examined. It is the rod-shaped and lightly protrusive lower end of the
embryonal axis that is found placed towards the micropylar end.
 The upper end of the embryonal axis exhibits the plumule.
 Hypocotyl is observed which is a section of the embryo axis found in between the
radicle and adjunct of cotyledon leaves.
 The epicotyl is also observed which is the section of the embryo axis between the
adjunct of cotyledon leaves and plumule.
Conclusion
Three principle parts of the embryo of dicot seeds are observed, they are:
 Cotyledons
 Plumule
 Radicle
Precautions
· Care needs to be taken while dissecting the seed as it may damage the seed.
· The cloth that is used to wrap the seeds needs to be moist.