ANTI-HEMOLYTIC ACTIVITY OF ADHATODA VASICA AND VITEX NEGUNDO

Anti-hemolytic activity of Adhatoda vasica and Vitex negundo.

Manoj Kumar, Sukumar Dandapat, Amit Kumar and M. P. Sinha

Department of Zoology, Ranchi University, Ranchi – 834008, Jharkhand, India.

Many plants produce biologically active substances, some may be responsible for special flavor or taste and other are/may be useful as antioxidants and/or antimicrobial agents. Antioxidants reduce the damage to cells and biomolecules caused by reactive oxygen species (ROS). The phytochemicals from plants such as phenols, saponins, flavonoids and tannins etc. are well known for their antibacterial and antioxidant properties, some are reported to possess an undesirable hemolytic activity of saponins present in the plant. Thus the present study was taken up to assess the phytochemicals and antioxidant properties of Adhatoda vasica and Vitex negundo and examined the hemolytic activity. The concentration of all the phytochemicals studied was higher in Vitex negundo than Adhatoda vasica, except alkaloids which was higher in Adhatoda vasica (11± 0.1mg/g) than 8.6±0.00 mg/g). Tannins were highest in both the plants, 61.3 ± 0.8mg/g in Adhatoda vasica and 93.9 ± mg/g in Adhatoda vasica. Both plants showed strong antioxidant and reducing power ability. The strong antioxidant and reducing power ability of the plant underlines their use as antioxidant supplement. Both the plants prevented the hemolysis of goat erythrocytes, that is Adhatoda vasica and Vitex negundo exhibited strong anti-hemolytic activity even at higher concentrations, thus they are further certified to be safe and useful for medicinal formulations.

Keywords:  Adhatoda vasica, Vitex negundo, reactive oxygen species, hemolytic activity, antioxidant, reducing

abstract published in Souvenir of International conference on HARMONY WITH NATURE IN CONTEXT OF ECOTECHNOLOGICAL INTERVENTION AND CLIMATE CHANGE. 2013: page  - 72-73

Antibacterial activity of Adhatoda vasica and Vitex negundo

Manoj Kumar

Department of Zoology, Ranchi University, Ranchi – 834008, Jharkhand, India

email: scholar.manojkumar@gmail.com 

The methanolic leaf extract of Vitex negundo and Adhatoda vasica were subjected to phytochemical, In-vitro antioxidant power analysis. The phytochemical studies showed the presence of alkaloids, tannins, flavonoids and saponins. The antioxidant activity was determined and compared with Butyl Hydroxy Anisole (BHA) as standard. The reducing power ability of both the plants were determined and compared with ascorbic acid as standard. Quantitative studies were also done. The extract was tested for antibacterial properties against five bacteria viz. Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Proteus mirabilis, Salmonella typhi Agar disc diffusion method and broth dilution method. The inhibition of microorganisms were compared within both plants and with pure antibiotic Gentamycin. The results exhibited strong antibacterial activity of Adhatoda vasica and Vitex negundo against B. subtilis and P. mirabilis. The minimum inhibitory concentration ranged from 0.612mg/ml in case of Vitex negundo and 2.5mg/ml in case of Adhatoda vasica.

Key words: Minimum inhibitory concentration, BHA, Gentamycin, antibacterial, antioxidant, phytochemicals

abstract published in Souvenir of International conference on HARMONY WITH NATURE IN CONTEXT OF ECOTECHNOLOGICAL INTERVENTION AND CLIMATE CHANGE. 2013: page  - 72 

PHYTOCHEMICAL SCREENING AND ANTIOXIDANT POTENCY OF ADHATODA VASICA AND VITEX NEGUNDO

8(2): 727-730, 2013, The Bioscan (Supplement on Medicinal Plants)

PHYTOCHEMICAL SCREENING AND ANTIOXIDANT POTENCY OF ADHATODA VASICA AND VITEX NEGUNDO

Manoj Kumar*, Amit Kumar, Sukumar Dandapat, M. P. Sinha

*Corresponding author email: eaddress.manojkumar@gmail.com

ABSTRACT

The leaf samples of Adhatoda vasica and Vitex negundo were subjected to phytochemical analysis. Both the plants contained antioxidant phytochemicals such as alkaloids, tannin, saponins, phenolics and flavonoids; which were present in comparatively higher amount in Vitex negundo. Tannins were recorded highest among all the phytochemicals (93.9 ± 0.8 and 61.3 ± 0.8 mg/g in Vitex negundo and Adhatoda vasica respectively). Phenolics were recorded lowest (13. ± 0.1 and 8.1 ± 0.5 mg/g in Adhatoda vasica and Vitex negundo respectively.The methanolic extracts of the plants were also analyzed for antioxidant and reducing power potentiality. Both plants showed strong antioxidant and reducing power ability. The strong antioxidant and reducing power ability of the plant underlines their use as antioxidant supplement against diseases such as typhoid during which antioxidant system fails; cardiovascular diseases which are caused due to accumulation of Reactive oxygen species; ageing related diseases, Alzheimer, Prkinson’s disease, Amytrophic lateral sclerosis, cataractogenesis and other diseases.

KEY WORDS: antioxidant, Adhatoda vaisca, Vitex negundo

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Anti-typhoid Activity of Adhatoda vasica and Vitex negundo

Persian Gulf Crop Protection

Available online on: www.cropprotection.ir

ISSN: 2251-9343 (Online)

Volume 2 Issue 3, September 2013

Pages 64-75

Anti-typhoid Activity of Adhatoda vasica and Vitex negundo

Manoj Kumar1*, Sukumar Dandapat1, Amit Kumar1 and M. P. Sinha1

1-Department of Zoology, Ranchi University, Ranchi, India (*Corresponding author e-mail:eaddress.manojkumar@gmail.com).

Abstract: Typhoid activity is an acute systemic infection caused by Salmonella typhi. In present study

the methanolic leafs extract of Vitex negundo and Adhatoda vasica were analyzed for anti-typhoid

activity against Salmonella typhi. The leave sample was subjected to phytochemical analysis. The

concentration of all the phytochemicals studied was higher in Vitex negundo than Adhatoda vasica,

except alkaloids which was higher in Adhatoda vasica (11.3 ± 0.1mg/g) than Vitex negundo (8.6 ± 0.00

mg/g). Tannins were highest in both the plants, 61.3 ± 0.8 mg/g in Adhatoda vasica and 93.9 ± 0.8

mg/g in Adhatoda vasica. The antioxidant activity was determined and compared with BHA and

reducing power was compared with Ascorbic acid. Both the samples had high antioxidant and reducing

power activity. Several studies reported the loss of antioxidant system during infection of Salmonella

typhi. The leaf extracts of Adhatoda vasica and Vitex negundo showed considerable antioxidant activity

which can used as remedy against antioxidant system collapse and thus promises to be effective

antioxidant supplement for typhoid patients. Besides antioxidant activity the leaves of both plants

inhibited the growth of Salmonella typhi. The antibacterial activity of both leaf extracts were compared

with gentamycin. The results of present study shows that leaf extracts of Vitex negundo and Adhatoda vasica

confer anti-typhoid activity against Salmonella typhi.

Key Words: Anti-typhoid, Adhatoda vasica, Vitex negundo.

Determination of Nutritive Value and Mineral Elements of Five-Leaf Chaste Tree (Vitex negundo L.) And Malabar Nut (Adhatoda vasica Nees)

Academic Journal of Plant Sciences 6 (3): 103-108, 2013
ISSN 1995-8986
© IDOSI Publications, 2013
DOI: 10.5829/idosi.ajps.2013.6.3.11011

Determination of Nutritive Value and Mineral Elements of

Five-Leaf Chaste Tree (Vitex negundo L.) And Malabar Nut

(Adhatoda vasica Nees)

Manoj Kumar*, Sukumar Dandapat, Amit Kumar and M.P. Sinha

Department of Zoology, Ranchi University, Ranchi - 834008, India.

Abstract: 

This study was undertaken to assess the nutritive value and mineral contents from Vitex negundo and Adhatoda vasica. These two plant species are fairly used as medicine throughout the greater part of India. Adhatoda vasica is used to control pain, inflammation and other related diseases. Leaves of Adhatoda vasica are used for treatment of cold, cough, chronic bronchitis and asthma. It was also used by traditional midwives at the time of delivery. The leaves of Adhatoda vasica are extensively used in indigenous medicines remedies. Both the plants contained important macro and micro elements: K, Ca, Fe, Cu, Zn and Cr. These elements were found in more quantity in Vitex negundo than in Adhatoda vasica. The leaves of both the plants were analyzed for ash content, moisture, crude fat, crude fibre, crude carbohydrate and crude protein content. The results for percentage of ash content, moisture content, crude fat, crude fiber, carbohydrate and protein were 5.4 ± 0.35, 16.50 ± 1.2, 7 ± 0.7, 28.02 +1.03, 8.5 ± 0.45, 13.7 ± 1.04 % respectively for Vitex negundo; and 5.2 ± 1.23, 15.3 ± 0.5, 1.6 ± 0.3, 6.4 ± 0.45, 16.4 ± 0.8, 6.5 ± 0.3 respectively for Adhatoda vasica. The leaves were also assessed for nutritional value. Nutritional value of Vitex negundo was 151.80 Cal/100g and that of Adhatoda vasica was 106.00 Cal/100.g.

Key words:

Vitex negundo, Adhatoda vasica, Nutritive value, Mineral contents

Corresponding Author: Manoj Kumar, Department of Zoology, Ranchi University, Ranchi - 834008, India.

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STUDIES ON ANTHERAEA MYLITTA DRURY HEMOCYTES DURING 3RD, 4TH LARVAL AND PUPAL STAGES

SOUVENIR AND BOOK OF ABSTRACTS, 4^TH InTERNATIONAL CONFERENCE OF NEA (ICAIECS), NOVEMBER 2012, 95.

STUDIES ON ANTHERAEA MYLITTA DRURY HEMOCYTES DURING 3RD, 4TH LARVAL AND PUPAL STAGES

MANOJ KUMAR and AMITABH HORE

DEPARTMENT OF ZOOLOGY, 

RANCHI UNIVERSITY, RANCHI

EMAIL: eaddress.manojkumar@gmail.com

ABSTRACT

Types of percentage occurrence of haemocytes in the blood lymph of Antheraea mylitta, have been studied using routine histological techniques through different larval and pupal stages. Blood smear from the proleg attatched to 7th abdominal segment shows the presence of five types of haemocytes namely:

1.      Prohemocytes (PRs)

2.      Plasmatocytes (PLs)

3.      Granulocytes (GRs)

4.      Spherulocytes (SPs)

5.      Oenocytoids (OEs)

The size and percentage of these hemocytes varied from stage to stage.

1.      GRs were prominent in pupal stages and disappeared during the wandering stage.

2.      Haemocyte titer decreased at pupation and declined after pupation.

3.      PLs were most abundant in pupal stages.

4.      OEs and SPs disappeared in wandering stages.

Histological observations revealed that PRS were round in shape and smaller than other haemocyte types and characterized by light purple staining of cytoplasm with Giemsa stain and a low concentration of granules in their cytoplasm. PRs measured 8.500 to 18.063 µm diameter and their nuclei, which stained in deep purple colour in Giemsa stain, were relatively large in comparison with other types. OEs were characterized by their spherical or ellipsoidal shape, large amount of cytoplasm and small nuclei. The mean length of larger axis was 21.548 ± 1.322 µm and smaller axis was 19.975 ± 1.344. The cytoplasm stained little yellowish red in Giemsa stain. PLs were round to elliptical in shape. Several fusiform PLs were also observed. The longer axis of elliptical forms ranged from 12.750 ± 23.375 µm and in fusiform cells it varied in between 17.00 to 34.00 µm. SPs were round to oval in shape. The longer axis of SPs from 12.750 ± 29.75 µm. and smaller axis ranged from 4.250 to 12.750 µm. The shape of the nucleus was irregular. GRs were recognized as spherical or oval shaped haemocytes, which varied considerably in size, the long axis of GRs ranged in between 12.750 to 25.500 µm. The short axis ranged between 8.500 to 23.375 µm. The cytoplasm had numerous vaclular bodies distributed around the nucleus. The nucleus stained deep purple and was irregular in shape. Densely dispersed cytoplasmic inclusions clearly distinguish GRs from other haemocytes. Probable involvement of these suspended cells in blood plasma in cellular defense, tissue repair and for transport and synthesis of nutrient and hormones has been discussed.

Keywords: Antheraea mylitta, Prohemocytes, Plasmatocytes, Spherulocytes, Granulocytes, Oenocytoids

INTERNATIONAL CONFERENCE ON HARMONY WITH NATURE IN CONTEXT OF ECOTECHNOLOGICAL INTERVENTION AND CLIMATE CHANGE (HARMONY - 2013)

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Revision test - 1 (Chemical reactions, life processes, Electricity)

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16^th June, 2013, STRT -1, Full marks – 45, Time – 1 ½ hr

1.     Write balanced equation for the following chemical reactions (a)Hydrogen + Chlorine à Hydrogen chloride (b)Sodium + Water à Sodium hydroxide + Hydrogen (c)Sodium hydroxide solution (in water) reacts hydrochloric acid solution (in water) to produce sodium chloride solution and water.

2.     Differentiate between respiration and photosynthesis, write their equation and balance them, what happens to glucose in aerobic, anaerobic respiration.[5]

3.     In an experiment with iron nail dipped in copper sulphate solution, why does the iron nail become brownish in colour and blue colour of copper sulphate solution disappear. [3]

4.     Give a balanced example each of (a) double displacement (b) exothermic (c) endothermic (d)double displacement reaction[4

5.     What are the benefits of separation of oxygenated blood from deoxygenated blood in mammals and aves. With the help of a diagram show the course of flow of blood in human circulatory system. What are the components of transport system in human beings? [2+2+1]

6.     Describe the structure and functioning of nephrons. What are the necessary conditions for autotrophic nutrition and what are its byproducts. [3+2]

7.     Differentiate between artery and veins.         [5]

8.     How much current will an electric bulb draw from a 220 V source, if the resistance of the bulb filament is 1200 Ω? (b) How much current will an electric heater coil draw from a 220 V source, if the resistance of the heater coil is 100 Ω?[5]

9.     An electric lamp, whose resistance is 20 Ω, and a conductor of 4 Ω resistance are connected to a 6 V battery in series.  Calculate (a) the total resistance of the circuit, (b) the current through the circuit, and (c) the potential difference across the electric lamp and conductor. [5]

10.                        What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series? [3]

11.                        Derive an equation for a system of resistors in series. [2]

Sex linked inheritance in humans

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Mendel’s laws are not applicable on those genes which are exclusively located either on X or Y gene chromosome. It has been observed that the genes only in X chromosomes are represented twice in females and once in male (because male have only one X-chromosomes). The sex linked inheritance can be classified into three types in XY type organisms.

1.      X-linked: here the linked genes are exclusively located on the non-homologous sections of X-chromosome, and do not have any corresponding allele on the Y-chromosome. These are called commonly as X-linked genes.

2.      Y-linked: the Y-Linked genes are localized on the non-homologous sections of Y-chromosome, and have no corresponding allele on the X-chromosome. The Y-linked genes are commonly known as Holandric genes.

3.      XY-linked: the XY linked genes are located on the homologous sections of X and Y chromosomes.

In human beings more than 150 confirmed or highly probable X-linked traits are known; most of these are recessives. Certain well known example of X-linked recessive genes in humares are those for red-green colour blindness and haemophilia.

Inheritance of X-linked genes:

1.      these genes whether dominant or recessive show there effects in male phenotypes.

2.      It shows criss-cross inheritance pattern (X-linked recessive genes are transmitted from P1 male to F1 female and from F1 female to F2 male)

3.      Usually none of the offspring of the affected male will be affected, but all of his daughters will carry the gene in masked heterozygous conditions.

Example: colour blindness, haemophilia.

Inheritance of Y-linked genes: the genes linked to Y-chromosomes are also called holandric genes. They are always transmitted from father to son.

Ex: the gene responsible for icthyosis hystrix gravis hypertrichosis (excessive development of pinnae hair) are transmitted from father to son only, because only the male posses the Y-Chromosomes.

INHERITENCE OF X-Y-LINKED GENES: the genes which occur in homologous sections of X and Y chromosomes have inheritance like an autosomal genes. .

PLEIOTROPISM

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• Pleiotropy refers to the situation in which a single gene influences more than one phenotypic trait.
• Most genes, if not all have their multiple effects and are called pleiotropic genes.
• The phenomenon of multiple effect (multiple phenotypic expressions of a single gene is called pleiotropism)
• Even though a structural gene may have many end effects, it usually has only one primary function, of producing one polypeptide. This polypeptide may give rise to different expressions at the phenotypic level.

Examples of pleiotropism

1.     In Drosophila the recessive gene for vestigial wings causes vestigial wings in homozygous condition and also effects other traits like:

Ø The tiny wing like balancer behind the wing

Ø Certain bristles

Ø The structure of reproductive organs

Ø Egg production is lowered

Ø Longevity is reduced

2.     In Drosophila the gene for white eyes may affect shape of sperm storage organs in females and also some other structures

3.     In human beings the gene for disease phenylketonuria has pleiotropic effect and produce various abnormal phenotypic traits. The affected individuals secrete large amount of an acid phynylalanine in their urine, cerebrospinal fluid and blood. They are short statured, mentally deficient with widely spaced incisors, pigmented patches on skin with excessive sweating and with non-pigmented hairs and eyes.

·      Pleiotropic genes must be more common because indirectly every gene may be involved in the expression of more than one trait. Thus most genes are pleiotropic IN NATURE

Hershey and chase experiment to prove that DNA is genetic material.

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Hershey (Alfred Hershey) and Chase (Martha Chase) performed a series of experiments in 1953 to prove that the DNA is the genetic material. The DNA was known to biologists since 1869, but still some scientists assumed that protein has some role in the inheritance. The key concept of their experiments was that Phage infection proved that DNA is the genetic material of viruses. When the DNA and protein components of bacteriophages were labelled with different radioactive isotopes, only the DNA is transmitted to the progeny phages produced by infecting bacteria.

First they labelled the bacteriophages with ³⁵S, since Sulphur is a component of protein coat of bacteriophage, the ³⁵S is incorporated to the coat of the bacteriophage. This bacteriophage was allowed to infect the bacteria. The bacteriophages infect the bacteria in a manner that their protein coat is left behind out side the bacterial cell and only the DNA of the bacteriophage enters the bacteria and incorporates with the genome of the bacteria. After the infection of the bacteriophage centrifugation is done to separate the capsids and the bacterial cells. It was found that ³⁵S was only found in the protein coat and not in the bacterial cells.

Secondly they labelled the bacteriophages with ³²P. Since Phosphorus is the essential component of the DNA. The ³²P was incorporated in the DNA of the bacteriophages. These labelled bacteriophages were allowed to infect the bacteria. The bacteriophages left their protein coat outside the bacterial cell and they injected their DNA into the bacterial cell which incorporated with the genome of bacteria. Then centrifugation was done to separate the protein coat and the bacteria. On testing ³²P was found in the bacterial cell. And not in the protein coat.

This experiment prominently proved that the DNA is the only genetic material, and the protein has nothing to do with the inheritance and genetic information.

Griffith and Avery’s experiment for the evidence that DNA is the genetic material.

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Genome consists of long sequence of nucleic acids that stores the information needed to construct the organism. The genome is the only thing that defines the hereditary nature of an organism.

The genome can be functionally divided in to genes. Each genes are nucleotide sequences that represent a particular protein. That is the genes code for the protein (Rather the genes code for an RNA which in turn may code for a specific protein.)

Experimental Evidence for DNA’s Role as Genetic material:

Griffith's experiment to show that DNA is genetic material.

The first direct evidence that the DNA transmits genetic information comes from the experiments of Griffith. In the year 1928 Griffith performed a fantastic experiment with mouse and bacteria (Streptococcus pneumoniae). The Streptococcus pneumoniae has two strains. One has smooth appearance due to presence of capsule, and are virulent to cause pneumonia, as the capsule allows the bacteria to escape destruction by the host. The other strain appears rough due to absence of the capsule, and is avirulent, because the host can easily destroy it. Avery first infected a mouse with the rough strain of bacteria, the mouse survived. Then he infected other mouse with the smooth strain, the second mouse died due to pneumonia. To the third mouse he infected it with heat killed smooth strain. The mouse survived. To the fourth mouse he infected with the mixture of heat killed smooth strain and live rough strain bacteria. Here the mouse died. Thus they concluded that the rough strain bacteria somehow transformed[1] itself to smooth strain and killed the mouse. These transformed bacteria were recovered from the dead mouse and then cultured. The result was culture of smooth strain, proofing that the transformation was permanent.

Drawbacks:

·         Griffith cannot explain the role of mouse in transformation of rough strain to smooth strain.

·         He also cannot make it clear, that which part of the smooth strain bacteria(DNA, RNA, protein etc) transformed the rough strain bacteria.

Experiment of Avery:

In 1944 Avery, C. Macleod and M. Mc Carty separated the extract of smooth, virulent bacteria into proteins, DNA, carbohydrate fractions. The incubated the rough strain of bacteria with all of these fractions. And they got the results. The only the bacteria incubated in the DNA fragment of the smooth strain bacteria, transformed to smooth strain. In other fractions there was no transformation. This experiment proved that it is the DNA which acts as genetic material.

---

[1] It is a permanent, inheritable change produced in one strain of bacteria by a substance (DNA) isolated from another strain of the same kind of bacteria

Aim: to study the response of the bacteria to the gram stain.

Aim: to study the response of the bacteria to the gram stain.

Requirements:
Slide, 90% alcohol, crystal violet stain, iodine reagent, saffranin, wash bottle, distilled water, pipette, spirit lamp, needle, microscope, bacterial stain.

Sample:
Bacterial sample (curd water)

Theory:
Fresh curd water may be smeared to have a leptococci and leptobacilli. Gram stain was developed             by Christian gram, a physician. According to the response of the bacteria to the gram stain, the bacteria are classified as gram negative and gram positive bacteria.

The bacteria are treated with crystal violet (primary stain) and iodine (mordant), formation of crystal-violet complex takes place which gets impregnated to the cell wall of the bacteria. After treating the stained bacteria with the ethyl alcohol (which acts as a decolourising agent) some bacteria retains their colour and some loose their colour. The bacterium which retains the colour is called as gram positive bacteria and the bacteria which loose the stain are called as gram negative bacteria.
The differential response of the bacteria to the gram stain is due to the composition of the cell wall. The gram negative bacterial wall has high lipid content, and so when the bacteria is washed with the ethyl alcohol then the lipid layer of the wall is dissolved and so does the crystal violet-iodine complex. This makes the bacterial wall colourless, and when these bacteria are treated with saffranin then the bacteria takes red coloured stain.

In the case of the gram positive bacteria the cell wall has insignificant lipid content and when the cell is washed with the decolourising agent then the bacteria retains the blue colour due to the presence of the Christian violet-iodine complex. Thus even if the bacterial is stained with the saffranin then also there is no scope for the bacteria to gain the red colour of safffranin, thus they remain violet coloured and hence is concluded as gram positive bacteria.

Procedure:
The slide was cleaned with the ethyl alcohol to make it grease free. A thin layer of smear of bacterial sample was made on slide by sterilised needle. The smear was allowed to be fixed by passing the slide quickly over the flame. Few drops of crystal violet were dropped over the smear. Crystal violet was drained away and iodine solution was added over the smear for 30 seconds. Smear was washed by dropping ethyl alcohol until no more colour flows from the smear. Smear was washed with distilled water and saffranin was applied to the smear for 30-60 seconds. Again smear was washed with sterile water. The slide was strained and dried in air.


Observations:
Smear was examined under low power then under high power and finally under oil emersion. Colour of the bacterial cell was noted. The bacterial cell retained the violet colour and hence is considered to be positive stain.
Shape of the bacterial cell was sketched.

Result:
Since the bacteria retained the stain that is the violet coloured; hence it is gram positive.

Precautions:
The slide was sterilised and handled carefully. During fixing care was taken while passing over the flame. All the apparatus including the chemicals and the spirit lamp were handled carefully.

Real time PCR

Real time PCR

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The real time polymerase chain reaction is also called as q-PCR (quantitative PCR).

It is a laboratory technique based on PCR, which is used to amplify and simultaneously quantify the targeted DNA molecule.

Its key feature is that the amplified DNA is detected as the reaction proceeds in real time.

The common methods:

1.       Use of non-specific dyes: the nonspecific dyes are not complementary to any specific sequences of the DNA, rather it intercalates with the double stranded DNA.

2.       Sequence specific fluorescent probes: consists of oligonucleotides that are labeled with fluorescent reporters, which permits detection only after hybridization of probe with targeted DNA.

3.       The probe is tagged with fluorescent materials (reporter) along with is attached the quencher molecule in very close proximity with the reporter. The quencher quenches (absorbs) the fluorescence of the reporter.

4.       The probe is first hybridized with the DNA, then the polymerase is allowed to perform its task, as the DNA polymerase adds nucleotides to the template strand, the flurophore is released away from the quencher molecule and the fluorescence is produced, depicting the formation of double stranded DNA. The intensity of fluorescence is directly proportional to the quantity of the ds DNA formed.

AGAROSE GEL ELECTROPHORESIS (AGE) Theory before performing electrophoresis

AGAROSE GEL ELECTROPHORESIS (AGE)

Theory before performing electrophoresis
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       AGE is the most convenient and easiest way to separate DNA molecules. The DNA molecules are separated on the basis of their size under the influence of an electric charge applied to the electrophoretic apparatus. The smaller molecules will travel faster and farther as compared to the bigger molecules which travel slower.

Agarose gel is obtained from Red Algae (Porphyra umbilicalis). The IUPAC name of agarose gel is

(1 4)-3,6-anhydro – α – L – galactosepyranosyl – (1 3) – β – D – galactopyranan

In general agarose gel is prepared between 0.2 – 0.7%. The 0.7% gel is ideal for the separation of larger molecules. And the 0.2% gel is ideal for separation of smaller molecules.

EAUIPMENTS AND MATERIAL NECESSARY FOR AGE:

1.       Electrophoretic apparatus:

2.       Gel casting trays:

3.       Sample combs: to form wells for samples to be loaded in the gel.

4.       Loading buffer: it allows the sample to be filled in the wells.

5.       Tracking dyes: it migrates in the gel with the DNA fragments and provides visualization for the proceeding status of the electrophoresis.

6.       Ethidium bromide: it is a fluorescent dye which can be seen under ultraviolet rays. It incorporates with the DNA fragments and when the gel is visualized under the UV rays. The ethidium bromide fluoresces to mark the location of the travelled DNA fragments in the gel.

7.       Transilluminator: it is an ultraviolet box. Which is used to visualized ethidium bromide stained separated DNA fragments after electrophoresis..

Soxhlet extraction: An introduction

Soxhletextraction

An introduction

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S

oxhlet extractor is a laboratory apparatus invented by Franz Von Soxhlet in the year 1879. Initially designed for the extraction of lipid from a solid material. But a soxhlet extractor is not limited to the extraction of lipids.

Normally a soxhlet extractor is employed for the extraction of compounds with limited solubility in a solvent, and the impurity is insoluble in that solvent. If the taken compound has a significant solubility in water, then simple water (aqueous) can be used to separate the compound from the insoluble substances.

The desired substance is placed in cellulose thimble, in the extraction chamber, the extraction chamber is placed over the collecting flask, over the extraction chamber is mounted the condensation chamber. A suitable solvent is added to the Distillation flask, and the setup is heated. After heating the solvent boils and evaporates and advances to the condenser through the bypass side arm. The vapour condenses and accumulates in the thimble, and gets siphoned in the Distillation flask.  And the process is repeated continuously depending upon the substance used for extraction. The main advantage of Soxhlet extraction is that it is a continuous process.

C.B.S.E. SA-II SCIENCE REVISION QUESTION PAPER

Shelford Tutorials

      Contact: manoj.kumar.mans@gmail.com website: www.mkshelford.blogspot.com  

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1.       Draw electron dot structure of H₂.

2.      What is the criteria for the arrangement of elements in the modern periodic table?

3.      Budding is one of the mode of reproduction in yeasts. [true/false]

4.    
The germ cells of human contains 23 pairs of chromosomes. [true/false]

5.      Who postulated the hypothesis -  ‘evolution takes place due to natural selection’

6.     What do you mean by acquired traits?

7.      Define focal length of a spherical mirror.

8.      What is Fovea centralis?

9.     Name one gas responsible for acid rain.

10.  What are two properties of carbon which lead to the huge amount of carbon compounds we see around us? 11. What do you mean by “Law of octaves”?

12.   Differentiate between atomic mass and atomic number.

13.   How does the creation of variations in a species promote survival?

14.  Give the phenotypic and genotypic ratio of a monohybrid cross.

15.  
Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

16.  What is Myopia? Suggest the corrective measures for it.

17.   Why is colour of sky blue?

18.   What is law of reversibility of light?

19.  What will be the formula and electron dot structure of cyclopentane?

20. (a) What were the limitations of Döbereiner’s classification?

(b) What were the limitations of Newlands’ Law of Octaves?

21.   How is the sex of the child determined in human beings?

22.  Describe the formation of rainbow with diagram?

23.  A convex mirror used for rear-view on an automobile has a radius of curvature of 3.00 m. If a bus is located at 5.00 m from this mirror, find the position, nature and size of the image.

24. An object is placed between the focal length and radius of curvature of a concave mirror. Draw a ray diagram to show the formation of image and right the characteristics of the image formed.

25.  Ethanol, commonly called as alcohol is an excellent solvent, is used in medicines and is an important chemical compound involved in synthesis of many chemical compounds. However in spite of its benefits to man, its impact on social behaviour has always been questioned. Media has often show abnormal behaviour of people while drunk. It is considered as a curse in the lives of those who are addicted to alcohol – ‘Alcoholic’ people are not only lowering their metabolism and affecting Central Nervous System, they are also a threat to the lives of others. Anger and rude behaviour are some of its ill effects.

(i)   Comment on the statement – ‘Should production of alcohol should be banned’, give three valid reasons to justify.

(ii)                        As a student what initiative would you take in the common concern of ‘Save Life, Do not Drink’. Give two suggestions.

Or

A 2.0 cm tall object is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. The distance of the object from the mirror is 15 cm. Find the nature, position and size of the image formed. Represent the situation with the help of a ray diagram.

26. Draw a well labeled diagram of human eye. What is power of accommodation?

Or

Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.

27.  Draw the electron dot structures of -- Cyclopentane, methane, S₈, N₂.

Or

Write the history of development of periodic table in brief.

Markings:  question no. 1 – 9 contains 1 mark each [1x9 = 9] Question no. 11 – 18 contains  2 marks each[2 x 9 = 18]

Question no. 19 – 24 contains 3 marks  each [3 x 6 = 18]

Question no. 25 – 25 contains 5 marks each [5 x 3 = 15]

Total = 9 + 18 + 18 + 15 = 70 marks