11 - EduSys A Spoiled Fruit 11 ... Discovery of electron, proton and neutron; ... inductive effect,...

Class - XI 3 Eduheal Foundation

CLASS ‐ XI S. No. Category Topic Page No.

1. Syllabus Guide Line 04

2. Invent Trick Birthday Candles 08

3. Explore Trial by Fire 09

3. Experiment A Spoiled Fruit 11

4. Explore What makes glass transparent? 14

5. Discover Blood and Scientific Method 17

6. Activity Photosynthesis 20

7. Experiment Enzyme Amylase Action on Strarch 21

8. Experiment How Good is Your Enzymatic Detergent? 23

9. Explore What We Don’t Know 26

10. Discover Jelly Optics 28

11. Explore & Experiment: Cracking Fun 29

12. Explore Chlorophyll Fluorescence 31

13. Explore Microorganisms Everywhere 32

14. Experiment Automn Leaves 34

15. Interactive Activity Who Ate the Cheese? 35

4 Class - XI Eduheal Foundation

CLASS VIII PHYSICS Physical World and Measurement Physics scope and excitement; nature of physical laws; Physics, technology and society. Need for measurement: Units of measurement; systems of units; SI units, fundamental and derived units. Length, mass and time measurements; accuracy and precision of measuring instruments; errors in measurement; significant figures. Dimensions of physical quantities, dimensional analysis and its applications. Kinematics Frame of reference. Motion in a straight line: Positiontime graph, speed and velocity. Uniform and nonuniform motion, average speed and instantaneous velocity. Uniformly accelerated motion, velocitytime, positiontime graphs, relations for uniformly accelerated motion (graphical treatment). Elementary concepts of differentiation and integration for describing motion. Scalar and vector quantities: Position and displacement vectors, general vectors and notation, equality of vectors, multiplication of vectors by a real number; addition and subtraction of vectors. Relative velocity. Unit vector; Resolution of a vector in a plane rectangular components. Motion in a plane. Cases of uniform velocity and uniform accelerationprojectile motion. Uniform circular motion. Laws of Motion Intuitive concept of force. Inertia, Newton’s first law of motion; momentum and Newton’s second law of motion; impulse; Newton’s third law of motion. Law of conservation of linear momentum and its applications. Equilibrium of concurrent forces. Static and kinetic friction, laws of friction, rolling friction. Dynamics of uniform circular motion: Centripetal force, examples of circular motion (vehicle on level circular road, vehicle on banked road). Work, Energy and Power Scalar product of vectors. Work done by a constant force and a variable force; kinetic energy, workenergy theorem, power. Notion of potential energy, potential energy of a spring, conservative forces: conservation of mechanical energy (kinetic and potential energies); nonconservative forces: elastic and inelastic collisions in one and two dimensions. Motion of System of Particles and Rigid Body Centre of mass of a twoparticle system, momentum conversation and centre of mass motion. Centre of mass of a rigid body; centre of mass of uniform rod. Vector product of vectors; moment of a force, torque, angular momentum, conservation of angular momentum with some examples. Equilibrium of rigid bodies, rigid body rotation and equations of rotational motion, comparison of linear and rotational motions; moment of inertia, radius of gyration. Values of moments of inertia for simple geometrical objects (no derivation). Statement of parallel and perpendicular axes theorems and their applications. Gravitation Keplar’s laws of planetary motion. The universal law of gravitation. Acceleration due to gravity and its variation with altitude and depth. Gravitational potential energy; gravitational potential. Escape velocity. Orbital velocity of a satellite. Geostationary satellites. Properties of Bulk Matter Elastic behaviour, Stressstrain relationship, Hooke’s law, Young’s modulus, bulk modulus, shear, modulus of rigidity. Pressure due to a fluid column; Pascal’s law and its applications (hydraulic lift and hydraulic brakes). Effect of gravity on fluid pressure. Viscosity, Stokes’ law, terminal velocity, Reynold’s number, streamline and turbulent flow. Bernoulli’s theorem and its applications. Surface energy and surface tension, angle of contact, application of surface tension ideas to drops, bubbles and capillary rise. Heat, temperature, thermal expansion; specific heat calorimetry; change of state latent heat. Heat transferconduction, convection and radiation, thermal conductivity, Newton’s law of cooling.


Thermodynamics Thermal equilibrium and definition of temperature (zeroth law of thermodynamics). Heat, work and internal energy. First law of thermodynamics. Second law of thermodynamics: reversible and irreversible processes. Heat engines and refrigerators. Behaviour of Perfect Gas and Kinetic Theory Equation of state of a perfect gas, work done on compressing a gas. Kinetic theory of gases assumptions, concept of pressure. Kinetic energy and temperature; rms speed of gas molecules; degrees of freedom, law of equipartition of energy (statement only) and application to specific heats of gases; concept of mean free path, Avogadro’s number. Oscillations and Waves Periodic motion period, frequency, displacement as a function of time. Periodic functions. Simple harmonic motion (S.H.M) and its equation; phase; oscillations of a spring–restoring force and force constant; energy in S.H.M.kinetic and potential energies; simple pendulum–derivation of expression for its time period; free, forced and damped oscillations (qualitative ideas only), resonance. Wave motion. Longitudinal and transverse waves, speed of wave motion. Displacement relation for a progressive wave. Principle of superposition of waves, reflection of waves, standing waves in strings and organ pipes, fundamental mode and harmonics, Beats, Doppler effect.

CHEMISTRY Some Basic Concepts of Chemistry General Introduction: Importance and scope of chemistry. Historical approach to particulate ature of matter, laws of chemical combination. Dalton’s atomic theory: concept of elements, atoms and molecules. Atomic and molecular masses. Mole concept and molar mass: percentage composition, empirical and molecular formula; chemical reactions, stoichiometry and calculations based on stoichiometry. Structure of Atom Discovery of electron, proton and neutron; atomic number, isotopes and isobars. Thomson’s model and its limitations, Rutherford’s model and its limitations. Bohr’s model and its limitations, concept of shells and subshells, dual nature of matter and light, De Broglie’s relationship, Heisenberg uncertainty principle, concept of orbitals, quantum numbers, shapes of s, p, and d orbitals, rules for filling electrons in orbitals Aufuau principle, Pauli exclusion principle and Hund’s rule, electronic configuration of atoms, stability of half filled and completely filled orbitals. Classification of Elements and Periodicity in Properties Significance of classification, brief history of the development of periodic table, modern periodic law and the present form of periodic table, periodic trends in properties of elements atomic radii, ionic radii, inert gas radii. Ionization enthalpy, electron gain enthalpy, electro negativity, valence. Chemical Bonding and Molecular Structure Valence electrons, ionic bond, covalent bond: bond parameters. Lewis structure, polar character of covalent bond, covalent character of ionic bond, valence bond theory, resonance, geometry of covalent molecules, VSEPR theory, concept of hybridization, involving s, p and d orbitals and shapes of some simple molecules, molecular orbital; theory of homo nuclear diatomic molecules (qualitative idea only), hydrogen bond. States of Matter: gases and liquids Three states of matter. Intermolecular interactions, type of bonding, melting and boiling points. Role of gas laws in elucidating the concept of the molecule, Boyle’s law. Charles law, Gay Lussac’s law, Avogadro’s law. Ideal behaviour, empirical derivation of gas equation, Avogadro’s number. Ideal gas equation. Derivation from ideal behaviour, liquefaction of gases, critical temperature. Liquid State Vapour pressure, viscosity and surface tension (qualitative idea only, no mathematical derivations).


Thermodynamics Concepts Of System, types of systems, surroundings. Work, heat, energy, extensive and intensive properties, state functions. First law of thermodynamics internal energy and enthalpy, heat capacity and specific heat, measurement of∆U and ∆H, Hess’s law of constant heat summation, enthalpy of: bond dissociation, combustion, formation, atomization, sublimation. Phase transition, ionization, and dilution. Introduction of entropy as a state function, free energy change for spontaneous and nonspontaneous process, equilibrium. Equilibrium Equilibrium in physical and chemical processes, dynamic nature of equilibrium, law of mass action, equilibrium constant, factors affecting equilibrium Le Chatelier’s principle; ionic equilibrium ionization of acids and bases, strong and weak electrolytes, degree of ionization, concept of pH. Hydrolysis of salts (elementary idea). Buffer solutions, solubility product, common ion effect (with illustrative examples). Redox Reactions Concept of oxidation and reduction, redox reactions, oxidation number, balancing redox reactions, applications of redox reactions. Hydrogen Position of hydrogen in periodic table, occurrence, isotopes, preparation, properties and uses of hydrogen; hydrides ionic, covalent and interstitial; physical and chemical properties of water, heavy water; hydrogen peroxidepreparation, reactions and structure; hydrogen as a fuel. sBlock Elements (Alkali and Alkaline earth metals) Group 1 and Group 2 elements: General introduction, electronic configuration, occurrence, anomalous properties of the first element of each group, diagonal relationship, trends in the variation of properties (such as ionization enthalpy, atomic and ionic radii), trends in chemical reactivity with oxygen, water, hydrogen and halogens; uses. Preparation and properties of some important compounds: Sodium carbonate, sodium chloride, sodium hydroxide and sodium hydrogen carbonate, biological importance of sodium and potassium. CaO, CaCO3 and industrial use of lime and limestone, biological importance of Mg and Ca Some pBlock Elements General Introduction to pBlock Elements Group 13 elements:General introduction, electronic configuration, occurrence. Variation of properties, oxidation states, trends in chemical reactivity, anomalous properties of first element of the group; Boron physical and chemical properties, some important compounds: borax, boric acids, boron hydrides. Aluminium: uses, reactions with acids and alkalies. Group 14 elements:General introduction, electronic configuration, occurrence, variation of properties, oxidation states, trends in chemical reactivity, anomalous behaviour of first element, Carbon catenation, allotropic forms, physical and chemical properties; uses of some important compounds: oxides. Important compounds of silicon and a few uses: silicon tetrachloride, silicones, silicates and zeolites. Organic Chemistry Some Basic Principles and Techniques General introduction, method, qualitative and quantitative analysis, classification and IUPAC nomenclature of organic compounds Electronic displacements in a covalent bond: inductive effect, electromeric effect, resonance and hyper conjugation. Homolytic and heterolytic fission of a covalent bond: free radicals, carbocations, carbanions; electrophiles and nucleophiles, types of organic reactions


Hydrocarbons Classification of hydrocarbons Alkanes Nomenclature, isomerism, conformations (ethane only), physical properties, chemical reactions including free radical mechanism or halogenation, combustion and pyrolysis. Alkenes Nomenclature, structure of double bond (ethene) geometrical isomerism, physical properties, methods of preparation; chemical reactions: addition of hydrogen, halogen, water, hydrogen halides (Markovnikov’s addition and peroxide effect), ozonolysis, oxidation, mechanism of electrophilic addition. Alkynes Nomenclature, structure of triple bond (ethyne), physical properties. Methods of preparation, chemical reactions: acidic character of alkynes, addition reaction of hydrogen, halogens, hydrogen halides and water. Aromatic hydrocarbons: Introduction, IUPAC nomenclature; Benzene: resonance aromaticity ; chemical properties: mechanism of electrophilic substitution. – nitration sulphonation, halogenation, Friedel Craft’s alkylation and acylation: directive influence of functional group in monosubstituted benzene; carcinogenicity and toxicity. Environmental Chemistry Environmental pollution air, water and soil pollution, chemical reactions in atmosphere, smog, major atmospheric pollutants; acid rain, ozone and its reactions, effects of depletion of ozone layer, greenhouse effect and global warming pollution due to industrial wastes; green chemistry as an alternative tool for reducing pollution, strategy for control of environmental pollution.

BIOLOGY Diversity in Living World Diversity of living organisms Classification of the living organisms (five kingdom classification, major groups and principles of classification within each kingdom). Systematics and binomial System of nomenclature Salient features of animal (non chordates up to phylum level and chordates up to class level) and plant (major groups; Angiosperms up to subclass) classification. Botanical gardens, herbaria, zoological parks and museums. Structural Organisation in Animals and Plants Tissues in animals and plants. Morphology, anatomy and functions of different parts of flowering plants: Root, stem, leaf, inflorescence, flower, fruit and seed. Morphology, anatomy and functions of different systems of an annelid (earthworm), an insect (cockroach) and an amphibian (frog). CELL: STRUCTURE AND FUNCTION Cell: cell wall, cell membrane and cell organelles’ (plastids, mitochondria, endoplasmic reticulum, Golgi bodies/ dictyosomes, ribosomes, lysosomes, vacuoles, centrioles) and nuclear organization. Mitosis, meiosis, cell cycle. Basic chemical constituents of living bodies. Structure and functions of carbohydrates, proteins, lipids and nucleic acids. Enzymes: types, properties and function. Plant Physiology Movement of water, food, nutrients and gases, Plants and Water Mineral nutrition, Respiration, Photosynthesis, Plant growth and development. Human Physiology Digestion and absorption. Breathing and respiration. Body fluids and circulation. Excretory products and elimination. Locomotion and movement. Control and coordination.


Have you ever seen a trick candle? You blow it out and it ‘magically‛ re-lights itself in a few seconds, usually accompanied by a few sparks. The difference between a normal candle and a trick candle is what happens just after you blow it out. When you blow out a normal candle, you will see a thin ribbon of smoke rise up from the wick. This is vaporized paraffin (candle wax). The wick ember you get when you blow out the candle is hot enough to vaporize the paraffin of the candle, but it isn‛t hot enough to re-ignite it. If you blow across the wick of a normal candle right after you blow it out, you might be able to get it to glow red-hot, but the candle won‛t burst into flame.

Trick candles have a material added to the wick that is capable of being ignited by the relatively low temperature of the hot wick ember.

When a trick candle is blown out, the wick ember ignites this material, which burns hot enough to ignite the paraffin vapour of the candle. The flame you see in a candle is burning paraffin vapour.

What substance is added to the wick of a magic candle? It‛s usually fine flakes of the metal magnesium. It doesn‛t take too much heat to make magnesium ignite (800° F or 430° C), but the magnesium itself burns white-hot and readily ignites the paraffin vapour. When a trick candle is blown out, the burning magnesium particles appear as tiny sparks in the wick. When the ‘magic‛ works, one of these sparks ignites the paraffin vapour and the candle starts to burn normally again. The magnesium in the rest of the wick doesn‛t burn because the liquid paraffin isolates it from oxygen and keeps it cool.

So next time when you cut your birthday cake surprise all guest with your magical candle.

Trick Birthday Candles


What is the flame test? Have you ever noticed that some substances give characteristic smell or colour when burnt. This property is used by scientists to recognise the unknown metal in an ionic salt. This type of testing is called flame test.

The flame test is used to visually determine the identity of an unknown metal of an ionic salt based on the characteristic colour the salt turns the flame of a bunsen burner.

How is the test performed? First, you need a clean wire loop! Platinum or nickel-chromium loops are most common. They may be cleaned by dipping in hydrochloric or nitric acid, followed by rinsing with distilled or deionized water. Test the cleanliness of the loop by inserting it into a bunsen burner flame. If a burst of colour is produced, the loop was not sufficiently clean. Ideally, a separate loop is used for each sample to be tested, but a loop may be carefully cleaned between tests.

The clean loop is dipped in either a powder or solution of an ionic (metal) salt. The loop with sample is placed in the clear or blue part of the flame and the resulting colour is observed.

What metals do colours indicate?

Trial by Fire


Colour

Red

Metal

Carmine: Lithium compounds, masked by barium or sodium. Scarlet or Crimson: Strontium compounds, masked by barium. Yellow-Red: Calcium compounds masked by barium.

Yellow Sodium compounds, even in trace amounts. A yellow flame is not indicative of sodium unless it persists and is not intensified by addition of 1% NaCl to the dry compound.

White White-Green: Zinc

Green

Emerald: Copper compounds, other than halides. Thallium. Blue-Green: Phosphates, when moistened with H SO or B O . Faint Green: Antimony and NH compounds. Yellow-Green: Barium, molybdenum.

2 4 2 3

4

Blue

Azure: Lead, selenium, bismuth, CuCl and other copper compounds moistened with hydrochloric acid. Light Blue: Arsenic and some of its compounds. Greenish Blue: CuBr , antimony

2

2

Violet

Potassium compounds other than borates, phosphates, and silicates. Masked by sodium or lithium. Purple-Red: Potassium, rubudium, and/or cesium in the presence of sodium when viewed through a blue glass.

What are the limitations of this test? There are some limitation of this test hence this is also performed as preliminary test. The value of the flame test is limited by interference from other brighter colours and by ambiguities where certain different metals cause the same flame colour. Sodium, in particular, is present in most compounds and will colour the flame. Sometimes a coloured glass is used to filter out light from one metal. Cobalt glass is often used to filter out the yellow of sodium.


You must have heard the saying, ‘one bad apple spoils the whole bushel‛? It‛s true. Bruised, damaged, or overripe fruit gives off a hormone that accelerates the ripening of the other fruit.

Plant tissues communicate by means of hormones. Hormones are chemicals that are produced in one location that have an effect on cells in a different location. Most plant hormones are transported through the plant vascular system, but some, like ethylene, are released into the gaseous phase, or air.

Ethylene is produced and released by rapidly-growing plant tissues. It is released by the growing tips of roots, flowers, damaged tissue, and ripening fruit. The hormone has multiple effects on plants. One is fruit ripening. When fruit ripens, the starch in the fleshy part of the fruit is converted to sugar. The sweeter fruit is more attractive to animals, so they will eat it and disperse the seeds. Ethylene initiates the reaction in which the starch is converted into sugar.

Iodine solution binds to starch, but not to sugar, forming a dark-coloured complex. You can estimate how ripe a fruit is, by whether or not it darkens after painting with an iodine solution. Unripe fruit is starchy so it will be dark. The more ripe the fruit is, the more starch will have been converted to sugar. Less iodine complex will be formed, so the stained fruit will be lighter.

Materials l 8 sealable plastic bags, large enough to contain a whole apple and banana

l 4 ripe bananas

l 8 unripe pears or 8 unripe apples (pears usually are sold unripe, so they may be a better choice than apples)

l potassium iodide (KI)

l iodine (I)

A Spoiled Fruit


l distilled water

l graduated cylinders

l large brown glass or plastic bottle (not metal)

l shallow glass or plastic tray or dish (not metal)

l knife for cutting fruit

Prepare the Test & Control 1. If you are not sure your pears or apples are unripe, test one using the

staining procedure outlined below before continuing.

2. Label the bags, numbers 1-8. Bags 1-4 will be the control group. Bags 5-8 will be the test group.

3. Place one unripe pear or apple in each of the control bags. Seal each bag.

4. Place one unripe pear or apple and one banana in each of the test bags. Seal each bag.

5. Place the bags together. Record your observations of the initial appearance of the fruit.

6. Observe and record the changes to the appearance of the fruit each day.

7. After 2-3 days, test the pears or apples for starch by staining them with the iodine stain.

Make the Iodine Stain Solution 1. Dissolve 10 g potassium iodide (KI) in 10 ml of water. 2. Stir in 2.5 g iodine (I). 3. Dilute the solution with water to make 1.1 litres. 4. Store the iodine stain solution in a brown or blue glass or plastic bottle.

It should last for several days.

Precautions l Do not use metal utensils or

containers for preparing or for storing the iodine solutions. Iodine is corrosive to metals.

l The iodine solutions will stain skin and clothing so handle carefully.


Stain the Fruit 1. Pour the iodine stain into the bottom of the shallow tray, so that it fills

the tray about half a centimetre deep.

2. Cut the pear or apple in half (cross section) and set the fruit into the tray, with the cut surface in the stain.

3. Allow the fruit to absorb the stain for one minute.

4. Remove the fruit and rinse the fruit with water. Record the data for the fruit, then repeat the procedure for the other apples/pears.

5. Add more stain to the tray, as needed.

Fruit Ripening Experiment ‐ Analyze the Data Examine the stained fruit. The best way to compare the data is to set up some sort of scoring. Compare the levels of staining for unripe versus ripe fruit. The unripe fruit should be heavily stained, while fully ripe or rotting fruit should be unstained. How many levels of staining can you distinguish between the ripe and unripe fruit?

Test Your Hypothesis If the ripening of the fruit was unaffected by storing it with a banana, then both the control and test groups should have the same level of ripeness.

Science Quotes from Kids l H 2 O is hot water, and CO 2 is cold water. l To collect fumes of sulfur, hold a deacon over a flame in a test tube. When you smell an odorless gas,

it is probably carbon monoxide. l Water is composed of two gins, Oxygin and Hydrogin. Oxygin is pure gin. Hydrogin is gin and water. l Three kinds of blood vessels are arteries, vanes and caterpillars. l Blood flows down one leg and up the other. l Respiration is composed of two acts, first inspiration, and then expectoration. l The moon is a planet, just like the earth, only it is even deader. l Dew is formed on leaves when the sun shines down on them and makes them perspire. l Mushrooms always grow in damp places so they look like umbrellas. l The pistol of a flower is its only protections against insects. l The skeleton is what is left after the insides have been taken out and the outsides have been taken off.


Glass is so common that most of us take it completely for granted. But just what is it about glass that makes it transparent? Why can we see through a window and not through the wooden frame that surrounds it?

You have probably noticed that most liquids and gases are transparent. Water, cooking oil, rubbing alcohol, air, natural gas, etc. are all clear. That‛s because of a fundamental difference between solids, liquids and gases. When a substance is in its solid state, normally its molecules are highly organized in relation to one another, strengthening the bond between them and giving the substance rigidity. As the substance changes from a solid to a liquid, however, the strength of the bond lessens and the molecules begin to align themselves randomly. If we follow the substance‛s progression to a gas, we see that the molecular bond is greatly weakened and the relationship of the molecules to one another is almost completely random.

This progression from ordered to random organization is the primary reason that light can pass through liquids and gases. Just like bricks stacked neatly on top of one another, the ordered molecules of most solids are virtually impenetrable to light waves. Depending on the substance, the light waves will be reflected, scattered, absorbed or, more likely, some combination of the three. But as the substance changes to liquid or gas and the molecules are not stacked neatly anymore, gaps and holes occur that allow portions of the light waves to pass through. The greater the randomness of the molecular organization of the substance, the easier it is for the light to pass through.

What Makes Glass Transparent?

Solid Liquid Gas


Another factor happens at the sub-atomic level. The atoms that bind together to make the molecules of any particular substance have electrons, usually lots of them. When photons come in contact with these electrons, the following can occur:

l An electron absorbs the energy of the photon and transforms it (usually into heat).

l An electron absorbs the energy of the photon and stores it (this can result in luminescence, which is called fluorescence if the electron stores the energy for a short time and phosphorescence if it stores it for long time).

l An electron absorbs the energy of the photon and sends it back out the way it came in (reflection).

l An electron cannot absorb the energy of the photon, in which case the photon continues on its path (transmitted).

Most of the time, it is a combination of the above that happens to the light that hits an object. The electrons in different materials vary in the range of energy that they can absorb. For example, a lot of glass, blocks out ultraviolet (UV) light. What happens is the electrons in the glass absorb the energy of the photons in the UV range while ignoring the weaker energy of photons in the visible light spectrum. If the electrons absorb the energy of any portion of the visible spectrum, the light that transmits through will appear coloured according to the portion of the spectrum absorbed. In fact, the colour of any object is a direct result of what levels of energy the electrons in the substance will absorb!

Although forms of glass, such as obsidian or volcanic glass, can occur naturally. Glass is generally a man made substance. Here is the basic way to make glass:

l Take the most common glass material, silica, which is just plain old sand like you would find on the beach.

l Heat it to an extreme temperature until it becomes liquid, then cool it.

The resulting substance has a molecular structure that is very random like a liquid yet that retains the strong bond and rigidity of a solid. This is a


simplification of the process. Usually you add both a substance to make the silica melt quicker and something else to stabilize it so that the glass is not brittle and easily broken. The temperature, heating time and cooling method must all be very exact.

The materials used for glass-making cool to form an amorphous mix of molecules (like a liquid) and have electrons that do not absorb the energy of photons in the visible spectrum. This is why you can see through glass, but not wood, metal or stone, which are all solids.

A similar method, called quenching, is used with plastics to make them transparent or translucent. Quenching causes the polymers (long-chain molecules) in the plastic to settle into a random pattern that allows light to pass through. You can even use this process with organic substances. Clear or translucent candy is created by heating the ingredients of the recipe and then rapidly cooling them.

Notice that clear glass, clear plastic and clear candy are all solids that are melted and then cooled in the same process!

Thousands of different substances are used to make various forms of glass. How much and what type of light is transmitted depends on the type and purity of the substance used. Silica, in its purest form, transmits light well. Very little of the light wave is absorbed, but some of it is usually reflected. Look at almost any window and you will see this is true.

Other materials used to make glass may transmit or block specific types of light, such as ultraviolet light, or even parts of the visible spectrum. You have probably seen glass that was black or some other opaque colour. Most often the colour is caused by microscopic particles suspended in the glass, like the impurities we talked about in some liquids and gases. Another way to change the properties of the glass, such as filtering specific wavelengths of light, is to slow down the cooling process enough to allow the molecules to partially crystallize, or form pattern. And finally, some materials are chosen because they can be shaped and made to transmit and/or refract light in specific ways to use, for instance, as eyeglass lenses or as a magnifying glass.


A scientific method started with forming a hypothesis. In this experiment you will learn to form a hypothesis, conduct experiments around that hypothesis, and collect and analyze data. One of the most important characteristics of modern science is its quantitative approach to solving problems. One of the first scientists to use quantitative methods was William Harvey, who discovered that blood circulated through the body. At the time Harvey began his work, anatomists believed that the liver produced blood from the food that the body consumed. The blood was then carried by veins to the heart, purified in the lungs, and then pumped to the various organs of the body, where it was consumed. Harvey measured that the left ventricle of the heart held roughly 100 ml of blood. He also measured that the heart beats an average of 64 times per minute.

Question 1: From the information above, and assuming that 1 ml of blood weighs 1 g, how much blood would the body need to produce per hour in (g/hr) to replace the blood consumed by the organs? ______g/hr. Harvey hypothesized that the same blood must circulate continuously throughout the body.

Materials: Watch with second hand, or clock

Procedure: 1. While sitting quietly in your room, find the pulse in your wrist and count the beats for one minute. You and your friend can do this on yourselves, or each other. Record the names of both subjects and their beats per minute heart rate on DATA TABLE 1 as sample 1.

2. Repeat step 1 two more times for each subject. Record the data in the appropriate place on DATA TABLE 1.

Blood and Scientific Method


3. Calculate the average pulse rate for each subject and record the results on DATA TABLE 1.

How do you think standing or holding your breath will affect your pulse rate? __________________________________________________________

Question 2:

Choose one of these activities and formulate a hypothesis about its effect on pulse rate. What is the independent variable? What is the dependent variable?

Hypothesis _________________________________________________

Independent Variable _________________________________________

Dependent Variable ___________________________________________

4. Repeat steps 1, 2, and 3 for each subject, this time with the subjects standing or holding their breath. Record your data and calculations in the appropriate DATA TABLE

DATA TABLE 1: Resting heart rate

SUBJECT sample 1 sample 2 sample 3

NUMBER OF BEATS PER MINUTE

AVERAGE NUMBER OF BEATS PER MINUTE


DATA TABLE 2: Heart rate standing


DATA TABLE 2: Heart rate holding breath


Conclusion: Compare your data from step 4 with your data from step 3. 1. How do your results in step 4 compare with the hypothesis you made?

_______________________________________________________ 2. What measurement did you use as a control in this investigation?

_______________________________________________________ 3. What are some possible sources of error in this experiment?

_______________________________________________________






Photosynthesis is one of the most important process. So let‛s see how much you about it. Fill in the blanks with the correct words from the word bank given below.

All organisms use __________ to carry out their life functions. Some organisms obtain this energy from __________. The process by which this energy transfer takes place is called _______________. Photosynthesis involves a _________ pathway in which the __________ of one reaction is consumed in the __________ reaction. __________ are organisms that carry on photosynthesis and includes __________ and other organisms containing the __________ pigment __________. Autotrophs use ______________ and water to make __________ and the simple sugar __________. The pigment chlorophyll absorbs __________ energy from the sun during the light __________. __________ pigments also in the __________ absorb other __________ of light that chlorophyll does not absorb. These accessory __________ are responsible for other colors we see in plants such as _______, orange, and __________. Chloroplasts are surrounded by a __________ membrane. Inside chloroplasts is a system of membranes arranged as stacks of __________ sacs called __________. Each sac in the stack is called a __________. The thylakoids are surrounded by a solution called the _________. The _______ reactions of photosynthesis take place in the stroma. Most chloroplasts are found in the _________ of plants. The __________ of a leaf contains openings called __________ where __________ such as oxygen and carbon dioxide enter and leave. These openings or stomata are __________ during the hottest times of the day by cells called __________ cells.

Word Bank: sunlight autotrophs carbon dioxide biochemical chlorophyll light photosynthesis next wavelengths energy plants glucose yellow accessory stroma chloroplast pigments reactions leaves oxygen dark stomata underside gases closed red thylakoids flattened guard double product granum green

Photosynthesis


In this experiment you will observe the action of the enzyme amylase on starch. Amylase changes starch into a simpler form: the sugar maltose, which is soluble in water. Amylase is present in our saliva, and begins to act on the starch in our food while still in the mouth.

Exposure to heat or extreme pH will denature proteins. Enzymes, including amylase, are proteins. If denatured, an enzyme can no longer act as a catalyst for the reaction. Benedict‛s solution is a test reagent that reacts positively with simple reducing sugars like maltose, but will not react with starch. A positive test is observed as the formation of a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange.

Materials: Cornstarch Distilled water Saliva Vinegar Benedict‛s qualitative solution 3 graduated cylinders (10mL) 250-ml beaker Stirring rod 3 test stand Test tube stand Marker Water Bath

PRE‐LAB:

Add 1g of cornstarch to a beaker containing 100ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.

Procedure:

1. Fill the 250-mL beaker about 3 / 4 full of water and place on the hot plate for a boiling water bath. Keep the water just at boiling.

2. Mark 3 test tubes A, B and C. “Spit” between 1 and 2 mL of saliva into each test tube.

Enzyme Amylase Action on Starch


3. Into tube A, add 2 mL of vinegar. Into tubes B and C, add 2 mL of distilled water. Thump the tubes to mix.

4. Place tube B into the boiling water bath for 5 minutes. After the five minutes, remove from the bath, and place back into the test tube rack.

5. Add 5 mL of the starch solution to each tube and thump to mix. Allow the tubes to sit for 10 minutes, occasionally thumping the tubes to mix.

6. Add 5 mL of Benedict‛s solution to each tube and thump to mix. Place the tubes in the hot water bath. The reaction takes several minutes to begin.

Observations:

Tube A: Starch + saliva treated with vinegar (acid).

Was the test positive or negative?_________________________________

What does this indicate?________________________________________

________________________________________________________________

Tube B: Starch + saliva and water, treated in a boiling water bath.

Was the test positive or negative?

__________________________________________________________


____________________________________________________________________

Tube C: Starch + saliva.

Was the test positive or negative?_________________________________


____________________________________________________________________

Q: Can you guess the name of a first year natural science college student who scored one “C” and 4 “F”s in five courses?

A: Carbon Tetrafluoride


“How Good Is Your Enzymatic Detergent?

In nature there are enzymes called proteases that “digest” or degrade proteins. Some of these enzymes have been genetically engineered and added to our laundry detergents in the hope that they will “digest” the protein off of our clothing. Do they work? Do they help in cleaning? In this experiment you can compare different detergents and their ability to “digest” protein.

What is gelatin? Gelatin consists of protein chains that are easily digested into their amino acid components. Gelatin is prepared from collagen, a protein found in animal tendons and skin and taken out during the meat rendering process. Boiling collagen reduces the weight by about one-third and separates the protein strands by breaking bonds. When the boiled collagen is cooled, it does not revert back to collagen but sets to a gel we know as gelatin.

Purpose: To test the effectiveness of laundry detergent brands (and their enzymes) to digest protein (in the form of gelatin).

Hypothesis: ____________ will decompose more gelatin in millimeters than ______________.

Materials: Gelatin in 4 test tubes Permanent marker 3 detergent brands Distilled water Test tube rack Ruler

Procedure: Day 1 1. Pour 5 ml of melted gelatin into 4 test tubes. Let the gelatin solidify.


2. Make 10% solutions of the five non-liquid detergents selected for testing. (Mix 10 g of detergent in 90 mL of distilled water). Label the solutions carefully and note whether enzymes are listed as a component of each.

3. Mark the top level of the gelatin with a permanent marker. Add 15 drops of each detergent solution to the top surface of the hardened gelatin in a test tube. To one tube add 15 drops of distilled water. Label carefully.

Day 2 4. After 24 hours examine the test tubes. Notice that the gelatin has been liquefied in some tubes. Use a ruler to measure the depth of the liquefication. Measure from the mark where the hardened gelatin started down to where it is still hard. Measure to the nearest mm. Record.

Day 3 5. Measure the depth of liquefication again after 48 hours.

Data 1 data table, 1 graph (time vs. mm. liquefied)

Enzymes listed? Liquefied After 24 Liquefied After hours (mm.) 48 hours (mm.)

Distilled Water

Detergent 1 ?

Detergent 2 ?

Detergent 3 ?

Now plot your observation on a graph.

Conclusion:

1. What is the job of enzymes?

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2. Why do laundry detergents often contain enzymes?

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3. Why was gelatin used in this lab?

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4. How is gelatin made?

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5. Name each of the laundry detergents you used and describe the effect each one had on the gelatin.

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_______________________________________________________

6. Did any of the laundry detergents contain enzymes? If so, which one(s)?

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7. Was your original hypothesis correct? Explain.

_______________________________________________________

_______________________________________________________


From the nature of the cosmos to the nature of societies, the following questions span the sciences. Some are pieces of questions others are big questions in their own right. Some will drive scientific inquiry for the next century; others may soon be answered. Many will undoubtedly spawn new questions. If you make your career in science you may be the one to find out the answer of any of the following question.

Is ours the only universe? A number of quantum theorists and cosmologists are trying to figure out whether our universe is part of a bigger “multiverse.” But others suspect that this hard-to-test idea may be a question for philosophers.

What drove cosmic inflation? In the first moments after the big bang, the universe blew up at an incredible rate. But what did the blowing? Measurements of the cosmic microwave background and other astrophysical observations are narrowing the possibilities.

When and how did the first stars and galaxies form? The broad brush strokes are visible, but the fine details aren‛t. Data from satellites and ground-based telescopes may soon help pinpoint, among other particulars, when the first generation of stars burned off the hydrogen “fog” that filled the universe.

Where do ultrahigh-energy cosmic rays come from? Above a certain energy, cosmic rays don‛t travel very far before being destroyed. So why are cosmic-ray hunters spotting such rays with no obvious source within our galaxy?

What We Don’t Know


What powers quasars? The mightiest energy fountains in the universe probably get their power from matter plunging into whirling super massive black holes. But the details of what drives their jets remain anybody‛s guess.

What is the nature of black holes? Relativistic mass crammed into a quantum-sized object? It‛s a recipe for disaster—and scientists are still trying to figure out the ingredients.

Why is there more matter than antimatter? To a particle physicist, matter and antimatter are almost the same. Some subtle difference must explain why matter is common and antimatter rare.

Does the proton decay? In a theory of everything, quarks (which make up protons) should somehow be convertible to leptons (such as electrons)—so catching a proton decaying into something else might reveal new laws of particle physics.

What is the nature of gravity? It clashes with quantum theory. It doesn‛t fit in the Standard Model. Nobody has spotted the particle that is responsible for it. Newton‛s apple contained a whole can of worms.

Why is time different from other dimensions? It took millennia for scientists to realize that time is a dimension, like the three spatial dimensions, and that time and space are inextricably linked. The equations make sense, but they don‛t satisfy those who ask why we perceive a “now” or why time seems to flow the way it does.


Can you ever imagine that jelly crystal, which is a kitchen ingredient can also help you in the physics lab? Come lets find out..........

What you need: a torch a comb a table two packets of jelly crystals (both the same flavour and preferably a light colour or clear). a rectangular plastic container, such as a lunch box, to use as a jelly mould a cutting board hot water a spoon a fridge a dark room a knife with a straight edge

What to do :

Mix up your jelly, but only use half as much.

1. Water as normal. You need to make very stiff jelly.

2. Pour the jelly into your mould and leave it to set overnight.

3. When the jelly has set, tip it out onto the cutting board. It is easier to tip out if you run a knife around the edge and then dip the outside of the mould into warm water for about ten seconds.

4. Use the knife to cut the jelly into the shape of some lenses such as: l wide in the middle and thin at the ends l thin in the middle and wide at the ends l semicircular.

5. Shine light from the torch through the lenses and look at how they bend the light. If you place a comb between the torch and the lenses, you will get lines of light, which can make it easier to see the light bending.

6. After you have finished, you can eat the jelly! Which way does the light bend?

Jelly Optics


What you need

To do this experiment you will need the following: a tin container with a tin lid, such as a coffee tin four long pencils a metal bottle cap (a soft drink bottle cap is less effective) strong sticky tape adhesive putty.

What to do 1. Fill the container with water until it is overflowing and press the lid on.

2. Place the metal bottle cap on the centre of the lid and secure it with a small piece of adhesive putty.

3. Place three of the pencils next to each other on the table and tape them together to make a flat platform.

4. Rest the container on the pencil platform so that the pencils poke out on both sides.

5. Place the fourth pencil on top of the bottle cap and fasten it with a bit of adhesive putty.

6. As one person holds all the pieces together, use strong tape to strap the top pencil tightly to the pencil platform on either side of the tin, and then place in the freezer.

Have a look after 24 hours (if you have used a large container it may take 48 hours). Marvel at the power of ice!

What’s happening

Water is one of a few chemicals that expands when it changes from liquid to solid. As water cools, it contracts like any other substance – the molecules slow down, they have less energy and get closer together.

Cracking fun


But as its temperature drops below four degrees Celsius, water begins to expand. The molecules begin forming stiff bonds with their neighbouring molecules, which push them outwards to form a hollow structure, or crystal lattice, which can float in liquid water.

As water freezes and expands, it can exert incredible pressure. For example, it has enough energy to burst open the walls of plant and animal cells, crack rocks, burst water pipes and crack your pencil!

Plant and animal cells contain water. As this water turns to ice, the cells expand, causing them to burst. In mountain and polar explorers, such burst cells can cause frostbite, which is an irreversible condition.

Also, severe damage to fruit and vegetable crops can occur when sudden cold snaps cause plant cells to burst.

APPLICATIONS People in cold climates need to add anti-freeze to the coolant in their motor vehicles. The anti-freeze lowers the freezing point of the coolant beyond the coldest temperature that the vehicle will be exposed to. This means that the coolant does not freeze solid and cause damage to the engine.

Some people believe that they can ‘cheat death‛ by having themselves cryogenically frozen. The idea is that if you die from an incurable disease such as cancer and have yourself frozen, you can be re-animated in the future once people discover a cure.

People who are cryogenically frozen are kept at temperatures well below –196° Celsius using liquid nitrogen. If they were to be placed straight into liquid nitrogen, all the cells in their body would freeze and burst. To prevent damage to the cells, all the water in the body is removed and replaced with a glycerol-based mixture called cryoprotectant, which is similar to antifreeze.

So far, dozens of people have been cryogenically frozen but no one has been reanimated – the technology to do so is yet to be discovered.


When a pigment absorbs light, electrons of certain atoms in the pigment molecules are to a higher energy level. The energy of an absorbed photon is converted to the potential energy of the electron that has been raised to an excited state. In most pigments, the excited electron drops back to its ground-state, or normal orbit, and releases the excess energy as heat. Some pigments, including chlorophyll, emit light as well as heat after absorbing photons. In the chloroplast, these excited electrons jump from the chlorophyll molecule to a protein molecule in the thylakoid membrane, and are replaced by electrons from the splitting of water. The energy thus transferred, is used in carbohydrate production. This release of light is called fluorescence. Chlorophyll will fluoresce in the red part of the spectrum, and also give off heat. In this experiment, you will observe this fluorescence by separating the chlorophyll from the thylakoid membrane.

Materials Spinach leaves Torchlight Mortar and pestle Test tube Acetone Filter paper Funnel Funnel rack Safety goggles 25-mL graduated cylinder

Procedure 1. Grind the spinach leaves using a mortar and pestle. 2. Add acetone to the ground leaves, using enough acetone and spinach leaves to get between 10 and 15 mL of extract. 3. Set up your filtering apparatus, and using proper filtering technique, filter the extract to a test tube. NOTE: Use a small amount of acetone to wet the filter paper, to hold it into place, instead of water. 4. Shine a torchlight or other similar light source, through the test tube and extract. 5. Observe the fluorescence of the chlorophyll at a 90 degree angle to the torchlight.

Chlorophyll Fluorescence


Although we can‛t always see them, microorganisms are present in almost all environments. Many can be grown in the laboratory on plates containing a solid, nutrient-rich medium (agar plates). After several days, a single fungal cell grows into a population of fungal cells that is visible to the naked eye. This population of cells is called a microbial colony. In this exercise we will test for the presence of microorganisms on our hands and on objects we are in contact with.

Materials : Sterile agar plates

Objects of your choice to test for the presence of microorganisms: a penny, keys, pens, etc.

Q-tips (to get fungi from teeth, sandwiches, fruit juice, etc.)

Toothpicks

Marker pens & spirit lamp

Cotton blue

Instructions ‐ First Week 1. Take an agar plate and label it on the bottom with your name and the date and the objects that you are going to test for microorganisms. This agar plate is sterile as it has been heated and no microorganisms are on it. Try dividing your plate into sections by drawing lines on the bottom of the plate (on the outside) using marker pens and trying different objects in each section.

2. Donot open the cover of the plate completely and gently press your object on the agar surface near a spirit lamp. Be careful not to press too hard as you don‛t have to press through the agar. Make sure to label what object you used in each section. If you want to try testing food, drinks, your teeth, etc.,

Microorganisms Everywhere


then wet the Q-tip with the object, and then rub the Q-tip on the surface of the agar. You can also use a toothpick.

3. Cover the plate as soon as you remove your object or the Q-tip or the toothpick. You want to have the lid open for as little time as possible so microorganisms from the air do not fall on the plate.

Your plate will be left at room temperature for a couple of days so any fungi that are present can grow into colonies. After colonies appear, the keep the plates in the refrigerator at 4°C.

Instructions ‐ Second Week 1. Record what happened on your plate.

1.1. Sketch your plate. Label your drawing so that you know what objects the colonies came from.

1.2. Record size, colour, texture, and shape of colonies.

2. Prepare samples of the microorganisms on your plate by using the cotton blue staining method.

2.1. Place a few drops of stain on the slide.

2.2. Use a toothpick to smear some of the fungal cells from one colony on the slide and mix it into the stain. You should take only enough fungito cover the tip of a toothpick. If you take too many cells, you won‛t be able to see them clearly under the microscope.

2.3. Carefully place the cover slip over the fungal cells.

3. For each sample, examine it under the microscope and draw the fungi. You will need to use the highest magnification on the microscope to see the fungi. Make sure you record which colony it came from.

4. On your plate, you used many different objects to grow fungi. Do some of the fungi colonies look similar? If so, why do you think this is?

5. If some fungal colonies look very different from one another, why do you think this is?


What you need: Covers for jars or aluminum foil or plastic wrap Leaves Small jars Rubbing alcohol Filter paper Shallow pan Hot tap water Tape, pen Clock or timer

What you do: 1. Collect 2-3 large leaves from several different trees. Tear or chop the leaves into very small pieces and put them into small jars labeled with the name or location of the tree. 2. Add enough rubbing alcohol to each jar to cover the leaves. Using a knife or spoon, carefully chop and grind the leaves in the alcohol. SAFETY NOTE: Isopropyl (rubbing) alcohol can be harmful if mishandled or misused. 3. Cover the jars very loosely with lids or plastic wrap or aluminum foil. Place the jars carefully into a shallow tray containing 1 inch of hot tap water. SAFETY NOTE: Hot water above 65°C can quickly cause severe burns. Experts recommend setting your water heater thermostat no higher than 50°C. 4. Keep the jars in the water for at least 45 mins, until the alcohol has become coloured (the darker the better). Twirl each jar gently about every five minutes. Replace the hot water if it cools off. 5. Cut a long thin strip of for each of the jars and label it. 6. Remove jars from water and uncover. Place a strip of filter paper into each jar so that one end is in the alcohol. Bend the other end over the top of the jar and secure it with tape. 7. The alcohol will travel up the paper, bringing the colours with it. After 30-90 minutes (or longer), the colours will travel different distances up the paper as the alcohol evaporates. You should be able to see different shades of green, and possibly some yellow, orange or red, depending on the type of leaf. 8. Remove the strips of paper, let them dry and then tape them to a piece of plain paper. This shows that the different pigment found in leaves with the help of technique chromatography.

Autumn Leaves


DNA isolation from blood, hair, skin cells, or other genetic evidence left at the scene of a crime can be compared with the DNA of a criminal suspect to determine guilt or innocence. This is due to the fact that every person has a different sequence. Scientists use a small number of sequences of DNA that are known to vary among individuals, and analyze those to get a possibility of a match. DNA is isolated, cut using restriction enzymes and sorted by size by gel electrophoresis. DNA is placed in a gel and an electrical charge is applied to the gel. The positive charge is at the top and the negative charge is at the bottom. Because DNA has a slightly negative charge, the pieces of DNA will be attracted to the bottom. The smaller pieces move more quickly towards the bottom than the larger pieces. The DNA can then be analyzed.

Objectives : In this simulation you will examine crime scene evidence to determine who is responsible for eating the special imported gift of Lindbergher Cheese to Princess Devjani of Jodhpur. You will model the process of electrophoresis and DNA fingerprinting

Royal Guard Incident Report

Incident Data

Incident Type: Theft Complaint Status: PendingDNA results Processed by: ACP Singh Other Officers: SP Rathore

Who Ate the Cheese? Sample Interactive Activity for Nationwide Science Olympiad


Property

Property Code: Rare cheese Owner‛s Name: Princess Devjani of Jodhpur

Name: Lindbergher Value: Rs. 5,40,000/-

Burglary Data

Method of Entry: Unknown, no evidence of force on doors or windows.

The cheese was allegedly stolen from the Princess‛s sitting room the night before her marriage. The cheese was listed as a gift from the English diplomat on her marriage due to her immense love of cheese. Officer SP Rathore dusted for fingerprints and found none on the table or doors, the maid claimed that they had been wiped clean earlier. The wheel of cheese was on a platform in the sitting room, and half of it had been eaten. He took pictures of the half eaten cheese and sent it to the lab in Jaipur for further tests. Mrs. Reena, the lab technician said that saliva samples could be taken from the teeth imprints of the cheese that was left behind.

Suspect Data

Suspect Number: 1 Name: Princess Maya

Description of Suspicion: The youngest princess was seen entering the sitting room earlier in the evening. She too is known for her love of cheese.

Suspect Number: 2 Name: Princess Dipannita

Description of Suspicion: This eldest of the three pricesses was against her sister‛s marriage. Her motive may have been to sabotage the diplomat‛s gift to Princess Devjani.

Suspect Number: 3 Name: Kusum Bai

Description of Suspicion: Bai was the maid in charge of cleaning the sitting room. She had access to the cheese.


Suspect Number:4 Name: Choudhary Dharam Singh

Description of Suspicion: He is Queen‛s brother, he may not have wished anyone else to give an expensive gift to the princess on her marriage.

Crime Lab Data Crime Lab S.K. Verma Lab Technician Mrs. Reena Investigator List of Evidence Plastic bag with List of Procedures DNA extraction Received cheese crumbs Used Polymerase Chain

Reaction DNA restriction Analysis

Narrative: After receiving the package with the plastic bag marked Crime Scene, the DNA was extracted. Because the sample was so small, the DNA was amplified using the polymerase chain reaction. They isolated the DNA from the four suspects and compared them to the crime scene DNA using DNA restriction analysis.

DNA Evidence Evaluation: 1. Turn your paper strips (DNA sequences) so that the side with the bases is facing you. The restriction enzyme cuts at every point it finds C C G G, always cutting between the C and the G. Label the back of the slips with the suspect number so that you don‛t get them confused after cutting. Use scissors to cut the DNA sequence at the C C G G points. 2. Count the number of base pairs (bp) in each piece of DNA that you created. Record the base pair number on the back side of the DNA fragment. 3. Make an enlarged chart like the one shown. Use a ruler to ensure that the lengths are uniform. 4. Tape your DNA fragments to the chart, using the base pair numbers as a guideline for fragment placement. 5. Compare the crime scene DNA to the suspects and indicate on your chart.


Crime DNA

Suspect 1

Suspect 2

Suspect 3

Suspect 4

12 bp


Now, answer these questions -

1.Who is guilty of eating the cheese? (a) Princess Dipannita (b) Kusum Bai (c) Princess Maya (d) Choudhary Dharam Singh

2.Which type of test is done to nab the culprit? (a) Blood test (b) HIV test (c) DNA test (d) None of these

3. Gel electrophoresis is a method (a) that joins fragments of DNA (b) that separates DNA fragments (c) Replicates DNA fragments (d) None of thesee

4. Restriction enzyme is (a) Restriction endonuclease (b) Exonuclease (c) Nuclease (d) Ribonuclease

5. Restriction enzymes are (a) DNA binding enzymes (b) DNA polymerizing enzyme (c) DNA cutting enzyme (d) None of these

6. Why Polymerase Chain Reaction is used in DNA finger printing? (a) DNA fragments can be made to replicate very rapidly (b)It makes the DNA fragments larger (c) This technique finds out the actual culprits in any crim (d) None of these

7. Which of the following application is incorrect about PCR (a) It can be used in DNA fingerprinting (b)It can be used to make synthetic food. (c) It can be used to detect the presence of unwanted of genetic materials. (d) To explore the genetic relatedness of organisms across species boundaries

& even across time.

11 - EduSys A Spoiled Fruit 11 ... Discovery of electron, proton and neutron; ... inductive effect,...

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