Class X
EXPERIMENT No: 10
AIM: To identify the different parts of an embryo of a dicot seed (Pea, gram or red kidney bean)
MATERIAL REQUIRED: Pea / gram / red kidney bean, Beaker, Cloth (cotton), Water, magnifying
glass, Toothpicks, Scissors, Paper plates.
PROCEDURE:
1)
Soak a few seeds of Bengal gram (chana)/kidney bean (rajma) in a beaker and keep
them overnight. Decant excess water and keep the seeds in a wet cloth. Leave them
for a day; now open the seeds carefully to observe the different parts.
2.
Find the largest kidney bean /Bengal gram seed you can. Peel off the seed coat VERY
carefully with toothpick. This seed coat protects the plants and keeps it from drying out.
3.
Now open the seed VERY carefully along its natural seam.
4.
The seed will divide into two parts. Each part is a cotyledon or seed leaf.
5.
The plant where seeds divide into two cotyledons are called dicot plants!
5.
Get a magnifying glass and look closely at the opened seed.
6.
On each cotyledon we find attached a minute plant like structure, this is called the
EMBRYO.
7.
The Embryo really is a very tiny plant! We can see the presence of plumule and radical
on the opposite terminals. The plumule gives rise to stem system and radical gives rise
to the root system.
Plumule
Axis
Radicle
Cotyledons
Internal Structure
External Structure
106
Embryo
OBSERVATION:
After removal of seed coat, at attachment point of two cotyledons we find a small embryo
consisting of radical and plumule.
INFERENCE:
Seed coat protects the inner parts of the seed. A seed contains two cotyledons hence is
called a dicot seed. Under favourable conditions the seed germinates .Radicle emerges first
followed by plumule.
PRECAUTIONS:
1.
Proper soaking should be done.
2.
Seed should be healthy.
3.
Seed coat should be properly removed.
107
COMPONENTS OF A GOOD LABORATORY
A good laboratory must have the followings :1.
Adequate furniture (stool/working table).
2.
Adequate lighting
3.
Sufficient water supply (either running or stocked in containers)
4.
Ample space for movement of students while performing the activity.
5.
Proper ventilation.
6.
Fans and exhaust fans.
7.
First aid material.
8.
Almirah/shelves for storage of articles
9.
Updated stock of materials
10.
Calm and serene atmosphere
11.
Displayed list of practicals, classwise
12.
Displayed record of experiments performed by students.
13.
Regular condemnation/write off of unservicable items.
14.
Regular deletion of consumable articles (at least once a year)
15.
Open the doors and windows during the work in the laboratory.
16.
Specimens, chemicals etc. should be kept at place after use.
17.
Gas connection should be put off after use.
108
List of Equipments/Materials used in Laboratory
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Ammeter
Awlpin
Beaker
Boiling Tubes
Burette
Brush
Battery
Clips
Crucible
Compound Microscope
Coverslips
Conical Flask
Cork
Chromatography paper
Cork borer
Connecting Wires
Dissecting Microscope
Dropper
Delivery Tube
Drawing Board
Drawing Pins
Forceps
Funnel
Filter Paper
Glass rods
Glass Slab
Hand Lens
Hammer
Key
Measuring Cylinders
Meter Scale
Magnets
Needle
Nails
Overflow Can
40. Permanent Slide of Binary fission in
Amoeba and Budding in yeast
41. Plier
42. Resitances
43. Rheostat
44. Scissors
45. Scalpel
46. Slides
47. Spirit Lamp or Burner
48. String or Cord
49. Stands (Iron wooden)
50. Staining Racks
51. Slinky
52. Spring balance
.
53. Specimens
54. Spherical Mirrors
55. Spherical Lenses
56. Test Tubes
57. Test Tube Stand
58. Tripod Stand
59. Thermometer
60. Test Tube Holder
61. Voltmeter
62. Weight Box
63. Whatman's Filter Paper
64. Watch Glass
65. Wire Gauge
66. Water bath
109
List of Chemicals
1.
Ammonium Oxalate
25.
Metal Strip
2.
Acetocarmine Stain
26.
Nitric Acid
3.
Acetic acid
27.
Potassium permanganate
4.
Acetone
28.
Potassium nitrate
5.
Aluminium sulphate
29.
Petroleum ether
6.
Acetone
30.
Potassium chloride
7.
Boric Acid
31.
Potassium hydroxide
8.
Benedict's reagent
32.
Potassium Iodide
9.
Biuret reagent
33.
pH paper/Tablets
10.
Cobalt chloride
34.
Potassium dichromate
11.
Copper sulphate
35.
Quick lime
12.
Distilled water
36.
Robert's Solution
13.
Etnanol
37.
Safranine Stain
14.
Fehling Solution 'A’
38.
Sulphuric acid
15.
Fehling Solution 'B’
39.
Sucrose
16.
Ferrous Sulphate
40.
Sodium hydroxide
17.
Glycerine
41.
Sodium carbonate
18.
Hydrochloric Acid
42.
Sodium chloride
19.
Iodine Solution
43.
Sodium III
20.
Litmus solution/Paper
44.
Starch
21.
Methylene Blue
45.
Sucrose
22.
Magnesium sulphate
46.
Sulphosalicylic acid
23.
Methanol
47.
Sodium Hydrogen Carbonate
24.
Million's reagent
48.
Zinc sulphate
110
111
112
123
F. Solid Reagents :
Aluminium powder, Ammonium chloride, Borax, Calcium chloride Lead dioxide, Magnesium
metal, Potassium nitrite, Potassium
permanganate, Potassium bisulphate, Potassium
dichromate, Potassium iodide, Sodium nitrate. Sodium bicarbonate, sodium nitrite, Sodium
peroxide, Sodium bisulphate, Zinc metal, Zinc chloride, α-naphthol.
Organic Liquids :
Petroleum ether, furfural, 2:4 dinitrophenyl hydrazine, glycerine
Organic Solids :
Pyrogallol. Resorcinol, Urea. β-naphthol.
Indicators :
Phenolphthalein soln. : Dissolve 5 g of phenolphthalein in 50 ml of rectified spirit and 500 ml
water with constant stirring. Filter, if necessary.
Litimus soln. (blue) : Dissolve 10 g of the solid in 100 ml of water.
Litimus soln. (red) : To 1% blue litmus soln. Prepared above, add a few drops of HCI till the
soln. Acquires a red colour.
Methyl orange soln. : Dissolve 1 g of solid in 1 litre of hot water and filter.
Methyl red soln. : Dissolve 1 g of solid in 0.5 litre of alcohol and dilute with water to 1 litre.
114
Stock Maintenance and Condemnation of Science
Laboratory articles
It is duty of Stock In-charge to maintain all stocks by registering receipts, issue of stock
items and make its disposal. Stock Registers have typical format showing all details of inward and
outward movement of articles for a given period of time. This is a summarized report of all the stock
items to help Store In-charge to keep better control on the movement of articles. Stock Register
maintenance ensure the effective inventory control, All items of the stock register are classified as
Non Consumable & Consumable.
Non Consumable Stores :
Non Consumable Stores are the stores which are intended to be used over prolonged
period of time then become unusable or obsolete in function. The stores which are sub-systems or
parts of an equipment potentially repaired and reused and stores which are fabricated equipments
or assembled equipment bought as a single item will be classified as Non Consumable Store.
All NCS will be entered into the Stock Register of the School or NCS stock register of
appropriate department. For example, these stores are Machinery, instruments, glassware,
motors, equipments or books etc.
Consumable Stores :
Stores satisfying any of the following conditions shall be classified as Consumable Stores
(CS).
i.
Stores which exhaust with the lapse of time.
ii.
Stores which do not have significant disposal value.
iii.
Spares of equipment which do not fall either in the NCS.
For example, Chemicals, medicines, stationery items, electronic components like resistors,
capacitors, connectors, wire, switches, plugs, bulbs, needle, brush, lab. preparation materials,
perishable items like paper and rubber, tool bits, hand tool etc.
Write off, Condemnation and Disposal :
An item may be declared surplus or obsolete or unserviceable, if the same is of no use to the
school or when the items is beyond economical repair. An item may be rendered surplus, obsolete
or unserviceable in the process of replacing school’s property or equipment no longer serves the
functional purpose. Under such circumstances the property and equipment be disposed off in the
best interest of the school as per the following guidelines with the prior approval of the Competent
Authority. These items are disposed off as per procedure.
General Procedure for writing off the unserviceable materials / items :
The items to be declared as obsolete / unserviceable should be examined by a committe at
appropriate level to be appointed by the Director to declare an item of store as obsolete or
115
unserviceable and order their disposal. The committee should take into prescribed / stipulate or it
is not over, the committee should examine the condition of stores and record suitable reasons.
Where the “life period” has been prescribed on any item and the same is already over, it
should normally be taken as enough ground for declaring the item obsolete and unserviceable.
However, the condition of the item should still be thoroughly examined to see whether the item
could be put to further use.
In other cases, where the life period is not or no life period has been prescribed or
stipulated, the reason for declaring the item unserviceable should be clearly recorded such as,
may be normal for declaring the item unserviceable should be clearly recorded such as, may be
normal wear and tear, excessive use in public interest, accidental fire, unintentional breakage,
flood and other natural causes, damage due to insect, rats etc.
An item may be declared obsolete / surplus if it is no longer required by the school. Reasons
for the same should be recorded.
In case of loss due to negligence, fraud or mischief on the part of any employee,
responsibility should be fixed and losses made good.
Authority competent to purchase stores shall be competent to declare the store as obsolete
/ surplus / unserviceable.
The condemnation Committee/Board shall submit its recommendations in the prescribed
form (i.e Form Ger - 17).
Actual physical disposal of items which have been declared obsolete will be done by public
auction only after the recommendations of the condemnation committee.
Procedure for Auction :
After approval / recommendations of Condemnation Committee, Head of the School shall
forward a copy each member open / sealed tendering. The Auction Committee shall decide the
mode of auction. The tenders in a sealed cover super-scribed “Tender for unserviceable materials”
should be submitted and will be opened in the presence of Committee members and tenderer who
may wish to be present.
The party whose tender is accepted will be required to deposit the amount after the receipt
of the order / notification. After depositing the amount, the party should lift the materials. If the
goods are not removed, the tenderer shall have no right or claim to the goods and whatever maony
have been deposited shall be deemed to have forfeited.
The sale account of auction shall be prepared (in triplicate) in the prescribed form (GFR 18). The members of Auction Committee shall arrange for the handing over of unserviceable
materials of the successful tenderer after the deposit of the auction money to the school chest. On
receipt of the sale account, school store in-charge will off the auctioned items from the Stock
Register on the written order of Head of the School.
116
Condemnation Process :
The Condemnation power for Non Consumable articles as per Order of Caretaking Branch,
Directorate of Education, GNCT Delhi is given below :
1.
Power of Condemnation :
As per Order F.No. 10(7) / CTB/Misc/Condemn./03-04/2132-3332 dated 17/6/2003.
2.
(a)
Head of School (Principal /Vice Principal)
Below Rs. 5000/-
(b)
D.D.E.
Between Rs. 5000/- to 24999/-
(c)
D.E.
Between Rs. 25000/- to 50000/
(d)
L.G.
Above Rs. 50000/-
Condemnation Board :
As per Order F.No. 10 (7)/CTB/Misc/Condemn./03-04/2132-3332 dated 17/6/2003.
(a)
E.O.
Chairman
(b)
HOS of neighboring School
Member
(c)
HOS of neighboring School
Member
(d)
Technical staff for sports/Lab. Library etc.
Member
(Sc. Counsellor of concerned Science Centre for Science articles)
(e)
DDO of the same school
Memebr
For articles costing Rs. 5000/- to 25000/(a)
E.O.
Chairman
(b)
HOS of neighboring School
Member
©
HOS of neighboring
Member
(d)
Technical staff for sports/Lab/Library etc.
Member
(e)
JAO/AAO of the concerned District
Member
117
LIFE OF ARTICLES
S. No.
(Articles)
Life (proposed)
(1)
(2)
(3)
1.
Almirah wooden
20 Years
2.
Almirah Iron
50 Years
3.
Black Board
3 Years
4
Black Board Stand
3 Years
5
Benches
5 Years
6.
Buckets (Tin)
2 Years
7.
Bicycles
8 Years
8.
Bicycles stand (iron)
10 Years
9.
Bicycles stand (wooden)
3 Years
10.
Chairs wooden seat
5 Years1
11
Chairs iron/steel seat
10 Years
12.
Chairs cane seat
5 Years
13.
Cash Box (wooden)
5 Years
14.
Cash Box (iron)
25 Years
15.
Chauki Takhat
10 Years
16.
Desks Single shift
7 Years
17.
Desks double shift
5 Years
18.
Stools
3 Years
19.
Durries
5 Years
20.
Racks (wooden)
10 Years
21.
Racks (iron)
25 Years
22.
Officers Table
20 Years
23.
Teachers’ Table
7 Years
24.
Office Table
10 Years
25.
Library Table
10 Years
118
26.
Laboratory Tables Physics
10 Years
27.
Laboratory Tables Chemistry
8 Years
28.
Lab. Tables Domestic Science
8 Years
29.
Biology
10 Years
30.
Table cloth
2 years
31.
Screens
10 Years
32.
News Paper Stand
5 Years
33.
Waste Paper basket (Tin)
5 Years
34.
Water Paper basket (Wooden)
3 Years
35.
Notice Board
5 Years
36.
Tray (Wooden)
5 Years
37.
Tray (Iron)
5 Years
38.
Paper stand
7 Years
39.
Foot Rest
5 Years
40.
Hat Hanger and looking glass
10 Years
41.
Confidential box
10 Years
42.
Teapoy wooden
10 Years
43.
Carpet
10 Years
44.
Trunk
10 Years
45.
Map stand
5 Years
46.
Cash safe
50 Years
119
CHEMISTRY APPARATUS (NON-CONSUMABLE)
S. No.
(Articles)
Life (proposed)
(1)
(2)
(3)
(a) Metal and Wooden Apparatus
1.
Balance (chemical)
5 Years
2.
Blow pipe (iron)
2 Years
3.
Burette stand (wooden)
2 Years
4.
Test-tube brush
1 Years
5.
Cork borer (iron)
2 Years
6.
Cork pressure (iron)
5 Years
7.
Crucible (Cilica)
2 Years
8.
Charcoal slab borer (iron)
2 Years
9.
Crucible (Cilica) Breakeable
2 Years
10.
Deflagrating spoon (iron)
5 Years
11.
Distillation apparatus (iron)
2 Years
12.
Drying cones (iron)
5 Years
13.
Funnel stand or filter stand (wooden)
2 Years
14.
Pestle and mortar
2 Years
15.
Pinch cock (iron)
2 Years
16.
Retort stand with ring and clamp
10 Years
17.
Round file
5 Years
18.
Sand Bath
5 Years
19.
Spirit Lamp (Brass)
4 Years
20.
Stoves
120
21.
Test-tube Holder (wooden)
2 Years
22.
Test-tube Holder (iron)
5 Years
23.
Triangular file (iron)
2 Years
24.
Tripod stand (iron)
5 Years
25.
Trough (tin)
2 Years
26.
Wire gauge (iron)
1 Years
27.
Wight boxes (wooden)
5 Years
28.
Triangular clay pipes
4 Years
(iron wire covered with clay)
(b)
Glass Apparatus
1.
Beehive shelf (Clay)
1 Year
2.
Beaker (Glass)
1 Year
3.
Burette (Glass)
3 Years
4.
China dish (Clay)
1 Year
5.
Conical flasks glass
1 Year
6.
Dessicator, Glass
5 Years
7.
Gas Jar discs glass
1 Year
8.
Flasks (F.B. & R.B.) Glass
1 Year
9.
Funnel Glass
1 Year
10.
Gas jar or cylinder glass
2 Years
11.
Glazsed tile glass
2 Years
12.
Measuring flasks glass
1 Year
13.
Pipette glass
1 Year
14.
Retort glass
1 Year
15.
Thistle funnel glass
1 Year
16.
Woulfs bottle glass
2 Years
121
17.
Nipple apparatus glass
3 Years
18.
Watch glass
1 Years
PHYSICS APPARATUS (NON-CONSUMABLE)
1.
Balance spring
5 Years
2.
Balance (physical)
5 Years
3.
Weight boxes
5 Years
4.
Boyles’ law apparatus
5 Years
5.
Vernier Callipers
5 Years
6.
Fortin’s Barometer
5 Years
7.
Metallic cylinders
5 Years
8.
Metal spheres
7 Years
9.
Metre scale
1 Years
10.
S.G. Bottle
5 Years
11.
Spherometers
5 Years
12.
Screw gauge
15 Years
13.
Stop watches
10 Years
14.
Inclined plane
5 Years
15.
Gravesands’ apparatus (for s/law)
5 Years
16.
Young’s modulus
5 Years
17.
Concave mirrors
2 Years
18.
Convex mirrors
5 Years
19.
Glass prisms
5 Years
20.
Glass slabs
5 Years
21.
Screen (glass)
2 Years
122
22.
Lens stands (wooden)
2 Years
23.
Optical bench (wooden)
2 Years
24.
Spectrometer
5 Years
25.
Wire gauge stand iron
3 Years
26.
Travelling microscope
10 Years
27.
Copper calorimeter
5 Years
28.
Hypsometer (copper)
5 Years
29.
Thermometers
1 Year
30.
Max. Min. thermometers
5 Years
31.
Magnets (bar)
5 Years
32.
Compass needles
3 Years
33.
Compasses (for time and force)
5 Years
34.
Deflection magnetometer
5 Years
35.
Ammeter
10 Years
36.
Voltameter
10 Years
37.
Galvanometers
7 Years
38.
Accumulators
2 Years
39.
Laclanche cell
2 Years
40.
Electric bell
2 Years
41.
Electrophorus
5 Years
42.
Gold leaf electroscope
5 Years
43.
Glass rods
1 Year
44.
Ebonite rods
1 Year
45.
Silk and cat skin pieces
1 Year
46.
Proof plane
2 Years
47.
Slide wire bridge
5 Years
123
48.
Potentiometer
5 Years
49.
One way and two ways keys
5 Years
50.
Resistance boxes
5 Years
51.
Resistance coils
5 Years
52.
Steding key (two key)
5 Years
53.
Tangent galvanometer
7 Years
54.
Induction coil
5 Years
55.
Torch lamp holder
2 Years
56.
Switches
1 Year
57.
Cutout fuses
1 Year
58.
Pliers
5 Years
59.
Spirit lamps
4 Years
60.
Tripod stands
5 Years
61.
Retort stand clamps
5 Years
62.
Tuning forks
2 Years
63.
Resonance apparatus
5 Years
64.
Stove (oil)
10 Years
65.
Binoculars
10 Years
66.
Soldering rods (fire)
5 Years
67.
Solder (electric)
2 Years
68.
Graduated cylinder
2 Years
69.
Glass plate machine
5 Years
70.
Sprit level
5 Years
71.
Battery clamps
3 Years
72.
Siren
7 Years
73.
Hydrometers
5 Years
124
74.
Lactometer
5 Years
75.
Drawing boards
2 Years
76.
Barometer tube
2 Years
77.
Photographic camera
20 Years
78.
Telescope
20 Years
79.
Newton’s Disc
10 Years
80.
Pin hole camera
10 Years
81.
Microscope
20 Years
82.
Epidiascope
10 Years
83.
Radio set
10 Years
84.
T.V. set
10 Years
NON-CONSUMABLE ARTICLES OF BIOLOGY
1.
Microscope
30 Years
2.
Dissecting microscope
10 Years
3.
Magnifiers (Tripod) and Hand lenses
10 Years
4.
Charts
3 Years
5.
Models
5 Years
6.
Stuffed animals
5 Years
7.
Skeletons (in show case)
10 Years
Skeletons (articulated)
8.
Preserved specimens in show cases
5 Years
9.
-do- in museum jars
5 Years
10.
Microslides prepared
5 Years
11.
Dissecting instruments
5 Years
12.
Dissecting dishes
5 Years
125