DINDIGUL NADAR URAVINMURAI

SMB MANICKAM NADAR PACKIATHAMMAL

NATIONAL PUBLIC SCHOOL

BIOLOGY BOARD PRACTICAL-2024-25

CLASS:XII STUDY MATERIAL

ISOLATION OF DNA FROM PLANT TISSUE

AIM:
To isolate the DNA from plant tissue like Papaya,Pea seeds,Spinach, etc.

MATERIALS REQURED:

BIOLOGICAL MATERIAL: Any of plant material like papaya pea

seeds ,spinach,onion,cauliflower or young leaves of plant.

GLASSWARE :Beakers ,test tube ,measuring cylinders glass rod ,droppers ,

conical flask ,ice cold pestle and mortar.

MISCELLANEOUS :Test tube stand ,water bath,refrigerator with temperature control,

filter paper,muslin cloth,forceps,blender,blade.

CHEMICALS: Palmolive liquid detergent ,distilled water non iodised sodium chloride
meat tenderizer 95%ethanol.

PREPARATION OF SOLUTIONS:
1. Prepare detergent salt solution by adding 10 ml detergent and 10g of salt to
90 ml of distilled water.
2. prepare 5% meat tenderizer solution to 95 ml of distilled water
3.95% ethanol must be left in plastic container in the freezer over night
4. Prepare 5% NaCl solution by adding 5g of non-iodized salt to 100 ml
distilled water.

PROCEDURE :
- Take plant tissue 100ml beaker add 10 ml of detergent salt solution.
Homogenised in a blender and filter through muslin cloth.
- To 10 ml of filterate ,add 3-4ml of meat tenderizer .swirl the tube to mix
- Carefully pour 10 ml of ice cold ethanol down the sides of test tubes to form a
layer on top.Let it settled for 3 mns.
- Using twirling motion of glassrod slowly move scored end of glass rod
through interforce of two layers to collect mucus like DNA and place it in test
tube with 5 % NaCl.

OBSERVATION:
Shiny white DNA is seen at the junction of two layers on adding ice chilled ethanol.
RESULT :
This DNA represent all the DNA found in plant cells.The chromosomes were
broken in the process and the DNA precipitated due to chemical treatment.

MINOR EXPERIMENTS: POPULATION DENSITY

AIM:
To determine and study plant population density of plants from the given
hypothetical data by the quadrate method.

METERIALS REQUIRED:
Scale and lead pencil.

PROCEDURE:
 Observe the given hypothetical data pertaining to distribution of various species
represented by the different symbols such as [ O, ◊, Δ, Ѳ,
Etc. for a given plant biodiversity.
 Make ten quadrates of 2 cm *2 cm randomly at different places in the given
hypothetical data.
 Count total no of individuals of one species in all the quadrates.
 Similarly count the total number of individuals of all the species in all quadrates.
 Divide the total number of individuals of each species by the total number of
quadrates under consideration for determination of population density of that species

SL. NUMBER OF Total TOTAL POPULATION

NO INDIVIDUALS
IN EACH number of NUMBER OF DENSITY
QUADRATE individuals QUADRATES
SPECIES of a
species in
all
quadrates
1 2 3 4 5 6 7 8 9 10
1 O 3 6 2 4 4 2 3 3 5 2 34 10 3.4
[A]
2 Δ 1 5 3 3 1 6 4 5 3 5 36 10 3.6
[B]
3 Ѳ 4 3 3 5 4 4 5 3 3 5 39 10 3.9
[C]
4 3 2 5 3 3 5 4 4 3 3 35 10 3.5
[D]
5 ◊ [E] 4 4 3 3 5 2 0 4 1 0 26 10 2.6
OBSERVATION TABLE

Total no.of individuals of a species in all quatrates

Population density of species =
Total number of quadrates
RESULT:
1.POPULATION DENSITY OF SPECIES ‘A’=34/10= 3.4
2.POPULATION DENSITY OF SPECIES ‘B’=36/10=3.6
3.POPULATION DENSITY OF SPECIES ‘C’=39/10=3.9
4.POPULATION DENSITY OF SPECIES ‘D’=35/10=3.5
5.POPULATION DENSITY OF SPECIES ‘E’=26/10=2.6

POPULATION FREQUENCY
AIM:
To determine and study plant population frequency of plants from the given
hypothetical data by the quadrate method.
METERIALS REQUIRED:
Scale and lead pencil.
PROCEDURE:
 Observe the given hypothetical data pertaining to distribution of various plant
species represented by the different symbols such as ( ) and labelled themas
A= ,B=, C=, D=, Etc. for a given plant biodiversity.
 Make ten quadrates of 2 cm X 2 cm randomly at different places in the given
hypothetical data of diversity.
 Count total no. of quadrates where plant sps. ‘A‘present
 Similarly count the total number of quadrates separately for plant species ‘B’ , ‘C’
and ‘D’
 Calculate the frequency of various plant sps.by following formula:

Numer of quadrets where the plant species is found

Population density of species =
Total number of quadrates under study

OBSERVATION TABLE
SI.N NUMBER OF INDIVIDUALS TOTAL TOTAL POPULATION
O NAM IN EACH QUADRATE NUMBE NUMBER DENSITY
E OF R OF OF
THE INDIVID QUADRA
PLAN UALS TES
T OF A
SPS. SPECIES
IN ALL
QUADR
ATES
1 2 3 4 5 6 7 8 9 10
1 A P P P A P P P A A P 7 10 7/10X100=70
%
2 B A P A A P P P A P A 5 10 5/10X100=50
%
3 C A P P P P P P P P A 8 10 8/10X100=80
%
4 D A A A P A A P A P P 4 10 4/10X100=40
%

RESULT:
1.Percentage of frequency of plant species ‘A’ =7/10 X100=70%
2. Percentage of frequency of plant species ‘B’ =5/10 X100=50%
3. Percentage of frequency of plant species ‘C’ =8/10 X100=80%
4.Percentage of frequency of plant species ‘D’ =4/10 X100=40%

MICRO SLIDE PREPARATION

AIM:
To study the different stages of mitosis in onion root tip from temprory or
permanent slides.

REQUIREMENTS :

Onion root tip,slides ,coverslips, filter paper ,Acetacarmine stain , dissecting

needles ,forceps,water ,water ,watch glass,microscope,sprit lamp,incubator,1 ml
NaCl,acetic acid ,methanol,formalin.

PROCEDURE:
To make slide of onion root tips :
 Remove the old roots from onion and put in beaker full of water ,new roots appear in
3-4 days.
 Cut the root tip when roots are about 2-3cm in length.
 Root tips are then transferred to carnoy’s fluid of 10 mns.
Carnoy’s fluid preparation:
Absolute alchohol(100%)…..30 ml.
Glacial acetic acid ……10ml
 Take a part of root tip on glass slide and put into drop of 1% Hcl and keep this 10
mns.
 Now to add 2-3 drops of acetacarmine for about 30 minute it makes the stain specific
nuclear materials
 Put the stain root tip in a drop of 45% acetic acid on slide, place coverslip over
it,gently press the cover slip with thumb it helps to spread uniform of squash.
 observe the slide first under the low power and then high power after locating a
specific area. Examine different stages of mitosis.
OBSERVATIONS :
Observe selected area under high magnification and identify various stages of mitosis

PROPHASE:

 Chromatin network begins to coil and appears as long thread -like structures
 Chromsomes consists two chromatids joined at point called centromere.
 Nucleolus disappeared earlier to late prophase and nuclear membrane disappeared at
late phase.

METAPHASE:

 It starts to completely disappearance of nuclear membrane.

 Chromatids become shorter thicker and condensed aquire specific shape and size.
 Chromatides move to the centre of the cell with their centromere arranged on
equatorial line.
 Spindle fibres appeared centromere of each chromosomes lies on the equator and is
attached to spindle fibres.

ANAPHASE:

 Centromere of each chromosomes divides into two so then each chromatids gets its
own centromere.
  Spindle fibres gradually shorter so each chromatids with its centromere is pulled
towards its respective poles.
 Each chromatids now behaves as an independent chromosomes and is thus known
daughter chromosomes. By the end of anaphase a cell plate is seen in the centre of
plant cells.

TELOPHASE:

 At each pole chromatids become uncoil thin invisible.

 Chromosomes again re-organised into network of chromatin threads.
 Nucleolus nuclear membrane reappear again .thus the two daughter nuclei are formed
each two poles of the cell
 The two daughter nuclei formed qualitatively and quantitatively similar to the parent
nucleus.
 Cell plates extends on either side completely divide the cytoplasm into two cell. the
cell plate known as middle lamella.

POLLEN GRAIN GERMINATION:

AIM:
To study the pollen germintaioin on a slide in a nutrient medium.

REQUIREMENT :
Different types of flowers Petunia, Catheranthes ,Hibiscus , Impatiens (balsom),
Grass ,slides ,cover slip,microscope,water,beaker,weighing machine ,filter paper,glass
rod ,boric acid,sucrose,potassium nitrate,magnesium sulphate.

PROCEDURE:
 Prepare a nutrient solution by dissolving 10g Sucrose,10g Boric acid ,50mg
Potassium nitrate,and 50mg Magnisium sulphate in 50ml of water.
 Dust the pollen from a flower over the slide .
 Put 2-3drops of nutrient solution over pollen grains and mix contents with
needle.
 Put the coverslip over gently and leave it for 10 minutes
  Observe it under the microscope to see the pollen germination and pollen tube
growth.
 If no pollen germination is seen wait 10-20 mns,and then observe under
microscope.
 Repeat step with flowers of other plants and record the time required for
pollen germination.
OBSERVATION:
Pollen grain of different plant spp.show the different types of sculpturing on the
exine .rate of pollen germination and viability also varies for different species.

Si.no Name of No.of the Total no.of % of pollen Time taken

the flower pollen pollen (b) germination for
showing =a/b x 100 germination
germination of pollen
(a)

RESULT AND DISCUSSION:

The viable pollen grains germinate in proper nutrient and show the viable length of
pollentubes. Pollen from different plant spp.take different time for their germination. Even
the pollen from different flowers have different ornamentation of exine.

SPOTTING

1.FLOWERS ARE ADAPTED TO POLLINATION BY DIFFERENT AGENCIES

[WIND,INSECTS,BIRDS]
Animophily:[wind pollination]:
 When the agent of pollination is wind, it is called Animophily.
 Flowers small, Colourless, odourless and nectarless.
 Calyx and corolla reduced.
 Pollens produced in huge quantities.
 Stigma large, well exposed, hairy, feathery to catch pollen.
Entomophily: [Insects pollination]

 Large, conspicuous, brightly Coloured and showy flowers to attract insects.

 Petal large and attractive.
 Flowers produce specific Odour to attract insects.
 Nectar secreted from nectaries of flower as source of food for insects.
Ornithophily [birds pollination]
 Flowers large with tubular or funnel shaped corolla.
 Flowers brightly coloured and produce abundant watery nectar.
 Odourless.
 Eg:Agave,bignonia,bombax.

2.POLLEN GERMINATION ON STIGMA THROUGH A PERMANENT SLIDE OR

SCANNING ELECTRON MICROGRAPH.

 It is the process of transfer of pollen grains from the anther to the stigma of the
flower.
 Stimulated by sugary substances from stigma.
 The pollen germinates and intine grows out as pollen tube which grows through
tissue of stigma and style.
 It carries the tube nucleus [vegetative nucleus]followed by two male gametes.
3. IDENTIFICATION OF GAMETE DEVELOPMENT, I. E, T.S. OF TESTIS AND T.S.
OF OVARY THROUGH PERMANENT SLIDES.
T.S. of Testes

 The testes comprise several seminiferous tubules embedded in the interstitial tissues.
 Thick fibrous tissues called tunica albuginea cover the testes.

 Sertoli cells are located between the germinal cells.

 The Leydig cells that produce testosterone are present in the interstitial tissues.

T.S. of Ovary

 An ovary is a germinal epithelium bounded by a solid structure covered by a thick

layer of fibrous tissue known as tunica albuginea.
 It consists of an inner medulla and an outer cortex.
 The medulla comprises several round or oval bodies known as ovarian follicles.
 Follicle development takes place in the following stages:
4.MEIOSIS IN ONION BUD CELL OR GRASSHOPPER TESTIS THROUGH
PERMANENT SLIDES.
Telophase stage:
 The chromatids (now the chromosomes) on the respective poles uncoil and form the
chromatin network again
 The nuclear membrane and nucleous reappear .
 Four haploid nuclei are seen in each cell.
 In plant cells ,middle lamella is formed to divide the cytoplasm into four cells, while
in animal cells pheriphery cytoplasm constricted into four parts

5.T.S.BLASTULA THROUGH PERMANENT SLIDES[MAMMALIANS]

T.S. of Blastula

 The blastula is an early embryonic stage that occurs during the development of many
animal species.
 It is characterized by a hollow, spherical structure, with a fluid-filled cavity called
the blastocoel.
 The blastula is formed through a series of cell divisions and differentiation events
that occur after fertilization.

 It plays a critical role in the establishment of the three germ layers that give rise to all
of the different tissues and organs in the body.

6.PREPARED PEDIGREE CHARTS OF ANY ONE OF THE GENETIC TRAITS

SUCH AS –
1.ROLLING OF TONGUE,
2.BLOOD GROUPS,
3.EAR LOBES,
4.WIDOW’SPEAK,
5.COLOR BLINDNESS.
1.ROLLING OF TONGUE,

 Tongue rolling trait is autosomal dominant trait [RR, Rr].

 Male parent is heterozygous tongue roller [Rr].
 Female parent is homozygous non- tongue roller[rr].
 Female daughter is heterozygous tongue roller [Rr].
 All grandchildren are homozygous non-tongue roller[rr].
2.BLOOD GROUPS

 Blood group is an autosomal multiple co dominant trait

 Inheritance of blood group is not related to sex-linked trait.
 Male parent with blood group ‘A’ is heterozygous [IA, Io].
 Granddaughter with blood group ‘A’ is also heterozygous [IA, Io].

3. EAR LOBES

 Attached ear lobe is an autosomal homozygous recessive trait.[ff].

 Female parent with free ear lobe trait is heterozygous (Ff)
 Male parent with attached ear lobe trait is homozygous recessive (ff)
 Son with free ear lobe trait is also heterozygous (Ff)
 All the grand children are homozygous recessive (ff)

4. WIDOW’SPEAK
  Widows speak is an autosomal dominant trait
 Female parent with widows speak hairline trait is heterozygous (Ww)
 Male parent with straight hairline trait is homozygous (ww)
 Male son (I-Generation ) is also heterozygous for widows speak hairline trait (Ww)
 All grand children are homozygous for straight line trait (ww)

5. COLOR BLINDNESS.

 Colour blindness is a sex linked homozygous recessive trait

 Colour blindness is related with X chromosome and is a homozygous recessive
trait.Hence female is either normal, carrier or colour blind where as male is either be
colour blind or normal but never be a carrier of colourblindness trait.
 Female parent in chart is the carrier of colourblindness trait
 Two grant daughter in the second generation are also carrier of colour blindness trait

7. CONTROLLED POLLINATION -EMASCULATION,TAGGING AND BAGGING

EMASCULATION
 Removal of anther from the bisexual flowers before the anthers mature is known as
emasculation.

 This process is carried out long before the anthers mature.

 The emasculated flower is then bagged to prevent any unwanted pollination.

 This process helps in the production of flowers with desired characteristics.

 Hand Emasculation. In species with large flowers, removal of anthers is possible with
the help of forceps.
BAGGING

 A plant breeding technique in which the stigma of a flower is covered with bags is
known as the bagging technique.
 In the bagging technique, the anthers of a bisexual flower are removed and the flower
is wrapped with paper bags or butter paper.
 This process ensures pollination with pollens from the preferred male parent.

TAGGING
 A tag is put up on the flower with important details
 like the date of emasculation,
 date of fertilization,
 Names of the father and mother plant's variety

10. MODELS SPECIMENS SHOWING SYMBIOTIC ASSOCIATION IN ROOT

NODULES OF LEGUMINOUS PLANTS, CUSCUTTA ON THE HOST, LICHENS
a. ROOT NODULES OF LEGUMINOUS PLANTS:

 Root nodules are commonly found in the roots of leguminous plants.

 They are formed due to association with a nitrogen-fixing bacteria, Rhizobium.
 Rhizobia is the general term used for different genera of nitrogen-fixing bacteria,
e.g. Rhizobium.
 It is used as a biofertilizer and reduces the use of chemical fertilizers.
b. CUSCUTTA

Cuscutta is a parasite plant

It’s a leafless plant and cannot perfom photosynthesis.
Hence it depends on other plants known s host plant,for its food.
It has sucking roots called haustorial roots whit penetrate into host plant
conducting tissue absorb water and food.

c. LICHENS

COMMON DISEASE – CAUSING ORGANISMS LIKE ASCARIS, ENTAMOEBA,

PLASMODIUM, AND ANY FUNGUS-CAUSING RINGWORM THROUGH
PERMANENT SLIDES, MODELS, OR VIRTUAL IMAGES OR
SPECIMENS.COMMENT ON SYMPTOMS OF DISEASES THAT THEY CAUSE.

ASCARIS.

 It is found as an intestinal parasite in the body of humans particularly small

children.it lies freely in the lumen of small intestine.
 The body is cylindrical and tapering at both the ends.
  The animal shows sexual dimorphism with separate male and female individuals.
 Males are smaller in size than females.
 Posterior end of male is curved having cloacal aperture and penial setae.

ENTAMOEBA:

 It is a microscopic protozoan which is monogenic endoparasite of humans.

 It is irregular in shape and has one large pseudopodia.
 It is an endoparasite of colon of large intestine of man.
 It causes amoebic dysentery or amoebiasis particularly in children of slum areas.
 In amoebiasis,fluid faecal matter associated with blood,mucous and cysts is passed
out.
PLASMODIUM:

 It is a protozoan, digenic and endoparasite of humans.

 Its primary host is human and secondary host is female Anopheles mosquito.
 It is causes malarial fever. Which is characterized by periodic reappearance of high
fever with chilling and shivering.
 Infection of malaria is spread through bite by female Anopheles mosquito.

RINGWORM:

 They are found as network of fine thread -like structures called mycelia which
usually spread under the surface of skin
 These mycelia feed on the keratin of skin /hair of human beings and cause skin
disease called ring worm/tenia
 These mycelia give out hyphae which grow up and bear spores called conidia.
 Conidia are small and produced large numbers .
  These spores are redily detachebale and can spread the infection and make the
disease ringworm highly contagious .
 Ringworm appears as round patches on skin which causes itching ,pinkish colour
slightly raised from the surface of skin with sharply defined edges.these patches of
ringworm blister and can ooze out.
 Personal ,family and community cleanliness is important to get rid this dreded
disease.

FLASH CARDS MODELS SHOW THE EXAMPLES OF HOMOLOGOUS AND

ANALOGOUS ORGANS.
HOMOLOGOUS ORGANS IN ANIMALS:

 Homologous organs are organs that have the same structural organization but
different functional properties.
 They have a common ancestral origin.
 These organs are anatomically similar.
 Homologous organs are a result of divergent evolution as they evolved through
a common ancestor.

HOMOLOGOUS ORGANS IN PLANTS:

 Homologous organs in plants are structures that are similar in origin and structure,
but may have different functions.
 For example, the roots of a plant and the stems are considered homologous organs
because they both develop from the same embryonic tissues, even though they serve
different purposes.