DHARMANANDA HARIPAL Roll NoClass-XII (Science)
This is certify that Dharmananda Haripal has Satisfactory completed the project in biology Prescribed by CBSE course in the lab Of this vidyalaya in the year 2017-18
Date charge
Teacher in
Submitted for the Practical Examination in Held on Teacher
Examiner
I am thankful to S.K.Mohanta (PGT BIOLOGY),JNV NARLA for providing necessary usefull guideness and suggestions in the selection for the project works and its completion. I must be thanksful to Mr. GVS Babu (Principal of JNV Narla) for his useful suggestion from time to time. I extend my thanks to Mr. Bhoi Lab. Attendant JNV NARLA for providing the essential material for the project. I could get the materials and guidelines from the Library of JNV NARLA. So I am thanking to Mr.R.Sika, Librarian, JNV Narla who provided me the facilities. I am also Highly grateful to my deep friends for their encouraging support for the completion of this Project Work.
Guided by-
Dharmananda Haripal
S .Mohanta
Class XII(science)
(PGT Biology)
The process of DNA fingerprinting was invented by Alec Jeffreys at the University of Leicester in 1985. He was knighted in 1994. DNA fingerprinting or DNA profiling, any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, semen, or other biological materials found at the scene of a violent crime. It depends on the fact that no two people, save identical twins, have exactly the same DNA sequence, and that although only limited segments of a person's DNA are scrutinized in the procedure, those segments will be statistically unique.
History of DNA Fingerprinting Up to 1984, the only method of establishing and authenticating personal identification was by the fingerprint process. DNA fingerprinting technique was devised in 1985 by Alec Jeffrey at University of Leicester in England, while working on the sequences within myoglobin gene.
What is DNA Fingerprinting ? It is a technique, by which an individual can be identified at molecular level. With the advancement of science and technology STR analysis has become very popular in forensic laboratories. Scientists have chosen repeating sequences in the DNA, which are present in all individuals on different chromosomes, and are known to vary from individual to individual except in identical twins. These are used as genetic markers to identify the Individual.
DNA fingerprinting technology DNA fingerprinting technology has made it possible to identify the source of biological samples found at scenes of crime. This will resolve disputes of maternity /paternity, identification of mutilated remains, identification of rape/ murder, identification of missing child, exchange of babies in hospital wards, forensic wildlife, protection of farmers rights and biodiversity. This remarkable technology provides exclusion as well as positive identification with virtually 100% precision.
Biological Material Used for DNA fingerprinting Blood Hair Saliva Semen Body tissue cells DNA samples have been obtained from vaginal cells transferred to the outside of a condom during sexual intercourse.
Stage Of DNA Fingerprinting • Cells broken down to release DNA
• DNA strands cut into fragments • Fragments separated • Pattern of fragments analysed
DNA fingerprinting: Methods A common procedure for DNA fingerprinting is restriction fragment length polymorphism (RFLP). In this method,DNA is extracted from a sample and cut into segments using special restriction enzymes. RFLP focuses on contain sequences of repeated DNA bases, which vary widely from person to person. The segments are separated using a laboratory technique called electrophoresis, which sorts the fragments by length. The segments are radioactively tagged to produce a visual pattern known as an autoradiograph, or DNA fingerprint, on X-ray film. A newer method known as short tandem repeats (STR) analyzes DNA segments for the number of repeats at 13 specific DNA sites. The chance of misidentification in this procedure is one in several billion. Yet another process, polymerase chain reaction , is used to produce multiple copies of segments from a very limited amount of DNA (as little as 50 molecules), enabling a DNA fingerprint to be made from a single hair. Once a sufficient sample has been produced, the pattern of the alleles (see genetics ) from a limited number of genes is compared with the pattern from the reference sample. A nonmatch is conclusive, but the technique provides less certainty when a match occurs.
DNA fingerprinting: Applications DNA fingerprinting can be applied in the following scenarios: Establishment of paternity and Maternity Establishment of the parentage for child swapping cases Establish the identity of the rapist in rape cases Identification of mutilated remains In murder, bomb blast, air crashes etc. Wild life identification, and Seed authentication.
Conclusion
In conclusion, while evidences can be tampered with and witnesses can turn hostile, DNA will never lie. It will indeed, unravel the truth even several decades after a crime has been committed. Such are the powers of DNA Fingerprinting.

BHAGWATI INTERNATIONAL PUBLIC SCHOOL Dr. Indu Dayal Meshri Primary English School
INVESTIGATORY PROJECT ON “ Logic Gates ”
Guided by: - Mr. Sandeep Darji Submitted by: - Rohan .D. Patel Roll no: -
This is to certify that Mr. Rohan Patel student of XII science Roll no ___________worked on project titled“Logic Gates” held in Bhagwati International Public School during the academic year 2016-2017. He worked sincerely under the guidance of faculties and prepared this dissertation.
External Teacher
Principal
Subject Teacher
ACKNOWLEDGEMENT First of all, I am immensely indebted to almighty god for his blessings and grace without which I could not have undertaken this task and my efforts would never have been a success. I humbly consider a privilege and honor to express my heartiest and profound gratitude to Mr. Rajendra.S. Malwal, principal BIPS, Patan. For his appropriate direction, valuable suggestion, under judging assistance so generously extended to me. I wish to express my deepest feelings of gratitude to Mr. Sandeep Darji, physics department, BIPS Patan. For his erudite involvement and sustained guidance which has been pivotal in my project work. His minute observation, precious insights, critical comments have indeed greatly helped to shape my ideas. This guidance and support received from my entire classmates who contributed and who are contributing to this project, is vital for the success of this project. I am grateful for their constant support and help. I also owe sense of gratitude to my parents for encouragement and support throughout the project.
- ROHAN PATEL
Content’s. Sr.no
Title
Page no.
1
Introduction
1
2
Principle
2
3
Basic Gates
3
4
The OR Gate
5
5
The AND Gate
7
6
The NOT Gate
9
7
The NOR Gate
11
8
The NAND Gate
13
9
The EX-OR Gate
15
10
The EX-NOR Gate
17
11
Conclusion
19
12
Bibliography
20
Introduction. GATE: - A gate is defined as a digital circuit which follows some logical relationship between the input and output voltages. It is a digital circuit which either allows a signal to pass through or stop it.  The logic gates are building blocks at digital electronics. They are used in digital electronics to change one voltage level into another according to some logic statement relating to them.
Truth Table: - A logic gate may have one or more than one inputs, but it has only one output. The relationship between the possible values of input and output voltages are expressed in the form of a table called truth table.  Truth table of a logic gate is a table that shows all the inputs and outputs that are possible for the logic gates.
Boolean Algebra: - The algebra which is based on binary nature of the logic gates.
Boolean Expressions: - They are the logical statement which are followed by logical gates.
1
Principle. Any Boolean algebraic operation can be associated with the input and output, which represents the statement of Boolean algebra. Although these circuits may be complex, they may all be constructed from three basic devices like a P-N junction diode, a resistance and a N-PN transistor. We have three different type of logic gates and they are the AND gate, the OR gate and the NOT gate.
LOGICAL STATEMENTS. 1
0
High
Low
Positive
Negative
On
Off
Close
Open
Conducting
Non-Conducting
Right
Wrong
True
False
Yes
No
2
Basic Gates. The OR Gate: - It is a device that combines A and B to give Y as the result. The OR gate has two or more inputs and one output. In Boolean algebra, addition symbol (+), is referred as the OR. The Boolean expression: A+B=Y This indicates that Y equals to A or B.
The AND Gate: - It is a device that combines A with B to give Y as the result. The AND gate has two or more inputs and one output. In Boolean algebra, multiplication sign is referred as the AND. The Boolean expression: A.B=Y or A X B=Y This indicates that Y equals to A and B.
3
The NOT Gate: - It is a device that inverts the inputs. The NOT has one input and has one output. In Boolean algebra, bar symbol is referred as the NOT. ̅=𝒀 The Boolean expression: 𝑨 This indicates that Y is not equal to A.
- Making of logic gates was started by binary numbers. - Logic gates can also store information.
4
The OR Gate. Aim: To design and stimulate the OR gate circuit.
Components: Two ideal p-n junction diode (D1 and D2).
Theory and Construction: An OR gate can be realized by the electronic circuit, making use of two diodes D1 and D2.
Hear the negative terminal of the battery is grounded and corresponds to the 0 level, and the positive terminal of the battery corresponds to level 1. The output Y is voltage at C with respect to earth.
5
The following conclusion can be drawn from the above circuit: (i)
If the switch A and B are kept open (A=1, B=0), then bulb does not glow, hence Y=0 If switch A is kept closed and B is kept open (A=1, B=0), then bulb does not glow, hence Y=0 If switch A is kept open and B is kept closed (A=0, B=1), then bulb does not glow, hence Y=0 If switch A and B both are kept closed (A=1, B=1), then bulb glows, hence Y=1
(ii)
(iii)
(iv)
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
0
0
1
0
1
0
0
1
1
1
6
The AND Gate. Aim: TO DESING AND STIMULATE THE AND GATE CIRCUIT.
Components:  Two ideal p-n junction diode (D1 and D2)  A resistance R.
Theory and Construction: An AND gate can be realized by the electronic circuit, making use of two diodes D1 and D2. The resistance R is connected to the positive terminal of a 5V battery permanently.
Here the negative terminal of the battery is grounded and corresponds to the 0 level, and the positive terminal of the battery corresponds to the level 1. The output Y is the voltage at C with respect to earth.
7
The following conclusion can be easily drawn from the working of this circuit: (i) (ii)
(iii)
(iv)
If the switch A and B are kept open (A=0, B=0), then bulb does not glow., hence Y=0. If switch A is kept closed and B is kept open (A=1, B=0), then bulb does not glow, hence Y=0. If switch A is kept open and B is kept closed (A=0, B=1), then bulb does not glow, hence Y=0. If both switch A and B are kept closed (A=1, B=1), then bulb glows, hence Y=1.
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
0
0
1
0
1
0
0
1
1
1
8
The NOT Gate. Aim: TO DESIGN AND STIMULATE THE NOT GATE CIRCUIT.
Components: An ideal n-p-n transistor.
Theory and Construction: A NOT gate cannot be realized by using diodes. However, an electronic circuit of NOT gate can be realized by making use a n-p-n transistor.
The base of the transistor is connected to the input A through a resistance Rb and the emitter is earthed. The collector is connected to 5V battery. The output Y is voltage at C with respect to earth.
9
The following inference can be easily drawn from the working of circuit: (i) (ii)
If the switch A is kept open(A=0) then bulb glows, hence Y=1 If the switch A is kept closed(A=1) then bulb does not glow, hence Y=0
TRUTH TABLE: Input A
OUTPUT Y
0
1
1
0
10
The NOR Gate. Aim: TO DESIGN AND STIMULATE THE NOR GATE CIRCUIT.
Component:  Two ideal p-n junction diode (D1 and D2).  An ideal n-p-n transistor
Theory and Construction: If we connect the output Y’ of OR gate to the input of a NOT gate, then the gate obtained is the NOR gate. The output Y is voltage at C with respect to earth.
11
In Boolean expression, the NOR gate is expressed as: (𝑦 = ̅̅̅̅̅̅̅̅ 𝐴 + 𝐵) And is being read as “A or B negated”.
Th following inference can be easily drawn from the working of electrical circuit: (i) (ii)
(iii)
(iv)
If the switch A and B is kept open (A=0, B=0) then bulb glows, hence Y=1. If the switch A is kept closed and B is kept open (A=1, B=0) then the bulb glows, hence Y=0. If the switch A is kept open and B is kept closed (A=0, B=1) then the bulb does not glow, hence Y=0. If the both switch A and B are kept closed (A=1, B=1) then bulb does not glow, hence Y=0.
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
1
0
1
0
1
0
0
1
1
0
12
The NAND Gate. Aim: TO DESIGN AND STIMULATE THE NAND GATE CIRCUIT.
Components:  Two ideal p-n junction diode(D1 and D2)  A resistance R  An ideal n-p-n transistor
Theory and Construction: If we connect the output Y’ of the AND gate to the input of a NOT gate then the gate obtained is the NAND gate. The output Y is voltage at C with respect to earth.
13
In Boolean expression, the NAND gate is expressed as: (𝑦 = ̅̅̅̅̅ 𝐴. 𝐵 ) And is being read as ‘A and B negated’.
The following inference can be easily drawn from the working of circuit: (i) (ii)
(iii)
(iv)
If the switch A and B are kept closed (A=0, B=0) then bulb glows, hence Y=1. If the switch A is kept open and B is kept closed (A=0, B=1), then bulb glows, hence Y=1 If switch A is kept closed and B is kept open (A=1, B=0), then bulb glows, hence Y=1 If both switch A and B are kept closed (A=1, B=1) then bulb does not glow, hence Y=0.
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
1
0
1
1
1
0
1
1
1
0
14
The EX-OR Gate. Aim: TO DESIGNA AND STIMULATE THE EX-OR GATE CIRCUIT.
Components:  Two AND gates  An OR gate  Two NOT gate
Theory and Construction: The operation EX-OR checks for the exclusivity in the value of the two signals A and B. It means if A and B are not identical, the output Y=1, and if both are identical, then output Y=0. This operation is also called exclusive OR gate, designated EX-OR.
15
In Boolean expression, the EX-OR gate is expressed as: (𝑦 = 𝐴 ⋅ 𝐵̅ + 𝐴 ⋅ 𝐵 = 𝐴 ⊕ 𝐵)
The following inference can be easily drawn from the working of electrical circuit: (i) (ii)
(iii)
(iv)
If the switch A and B are kept open (A=0, B=0) then bulb does not glow, hence Y=0 If the switch A is kept open and B is kept closed (A=0, B=1) then bulb glows, hence Y=1 If the switch A is kept closed and B is kept open (A=1, B=0) then the bulb will glow, hence Y=1 If the switch A and B are kept closed (A=1, B=1) then bulb will not glow, hence Y=0
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
0
0
1
1
1
0
1
1
1
0
16
The EX-NOR Gate. Aim: TO DESIGN AND STIMULATE THE EX-NOR GATE CIRCUIT.
Components:  Two AND gates  And OR gate  Three NOT gates
Theory and Components: The operation EX-NOR checks for the exclusively in the value of the two signals A and B. it means if A and B are not identical, the output Y=0, and if both are identical, then the output Y=1. This operation is also called exclusive NOR gate, designated EX-NOR.
17
In Boolean expression, the EX-NOR gate is expressed as (𝑦 = 𝐴 ⋅ 𝐵̅ + 𝐴̅ ⋅ 𝐵 = ̅̅̅̅̅̅̅̅ 𝐴 ⊕ 𝐵)
The following inference can be easily drawn from the working of electrical circuit: (v)
If the switch A and B are kept open (A=0, B=0) then bulb glows, hence Y=1 (vi) If the switch A is kept open and B is kept closed (A=0, B=1) then bulb does not glow, hence Y=0 (vii) If the switch A is kept closed and B is kept open (A=1, B=0) then the bulb does not glow, hence Y=0 (viii) If the switch A and B are kept closed (A=1, B=1) then bulb will glow, hence Y=1
TRUTH TABLE: Input A
Input B
OUTPUT
0
0
1
0
1
0
1
0
0
1
1
1
18
Conclusion. Logic gates are used to develop many IC circuits or microchips in today’s modern world. NAND gate and NOR gate are known as universal gates because we can construct all the three basic gates using NAND & NOR gates.
Without logic gates, electronic world would be nearly incomplete!
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Bibliography. This project would be nearly incomplete if I had not used the information given in the following websites. My special thanks to the uploader of information on these websites. If considered, I have used everything that GOOGLE shows me…….
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