Heredity

                                                                         Heredity

* The Heredity is nothing but transmission of genetic characters from parents to offspring .

* Heredity is the passing on of traits from parents to their offspring, either through asexual reproduction or sexual reproduction
*  The offspring cells or organisms acquire the genetic information of their parents.
* Genetics:-  The study of heredity in biology is called genetics, which includes the field of epigenetics.

* The genotype–phenotype distinction is drawn in genetics. "Genotype" is an organism's full hereditary information. "Phenotype" is an organism's actual observed properties, such as morphology, development, or behavior. This distinction is fundamental in the study of inheritance of traits and their evolution.

Mendel developed 3 principles of inheritance based on his experiments with pea plants.

Our understanding of how inherited traits are passed between generations comes from principles first proposed by Gregor Mendel in 1866. Mendel worked on pea plants, but his principles apply to traits in plants and animals – they can explain how we inherit our eye colour, hair colour and even tongue-rolling ability.
Inheritance in pea plants

Mendel followed the inheritance of 7 traits in pea plants 
Pea shape (round or wrinkled)
Pea colour (yellow or green)
Flower colour (purple or white)
Flower position (terminal or axial)
Plant height (tall or short)
Pod shape (inflated or constricted)
Pod colour (yellow or green). 

Mendel followed the inheritance of 7 pea traits. Dominant traits, like round peas, appeared in the first-generation hybrids (F1), whereas recessive traits, like wrinkled peas, were masked. However, recessive traits reappeared in the second generation (F2). And found a 3:1 ratio of dominant to recessive traits. He concluded that traits were not blended but remained distinct in subsequent generations, which was contrary to scientific opinion at the time.
Each individual carries a pair of factors for each trait, and they separate from each other during fertilisation. This is the basis of Mendel’s principle of segregation.

Mendel didn’t know about genes or discover genes, but he did speculate that there were 2 factors for each basic trait and that 1 factor was inherited from each parent.



 Sex determination in Human beings 

•Sex is determined at the time of fertilization and depends on the type of sperm that fuses with the ovum. If the X-carrying ovum is fertilised by a X-carrying sperm the resulting zygote will have a sex chromosome XX. Such a zygote develops into a female. If the X carrying ovum is fertilised by a Y-carrying sperm. The resulting zygote will have a sex chromosome XY. Such a zygote develops into a male.So it is the presence or absence of Y chromosome that determines the sex.
•Meiosis takes place at the time of  gamete formation when the chromosome number is reduced to  half  (n) and it is called haploid.When the gametes fuse together to form an individual the chromosome number is again retained  to 2n  number of chromosome and the condition is called Diploid.

Evolution 

Evolution is  change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms

LAMARCK’S THEORY OF EVOLUTION
Different scientists have tried to explain the process of organic evolution. So they have given different theories for the Evolution of organisms. Out of them the names of three scientists are important Carlos Linnaeus, Jean Baptist de Lamarck and Charles Darwin but we shall discuss the two important theories of evolution which are put forward by Lamarck and Darwin.
Lamarck’s Theory of Evolution or Lamarckism

This theory was given by a famous biologist Jean Baptist de Lamarck in 1744,  in his book ‘Philosphie Zoologique’. 

The main postulates of Lamarck’s theory of evolution are: 
1. Effect of the environment 
The change in the environment creates new needs in organisms, which results in change of habits of organisms. The new habits involve more use of certain organs of the body and on the other hand less use of other body organs. 

2. Use and disuse of organs
 The use and disuse of organs by an organism leads to acquisition of new characteristics. 

3. Inheritance of acquired characters  The characters acquired by an individual are then transmitted by heredity to the next generation. In this way, in every generation new characters get accumulated and after a number of generations, a new species with modified characters is formed.

DARWIN’S THEORY OF EVOLUTION OR DARWINISM

The theory of ‘natural selection’ for organic evolution was given by Charles Darwin in 1858 in his famous book ‘The Origin of Species’. This theory was widely accepted by various biologists. 

The main postulates of Darwin’s theory of evolution are: 


1. Rapid multiplication
All the animals and plants tend to increase their population, but the number of individuals of each species remains nearly constant naturally. 

2. Competition and struggle for existence

        This is due to the reason of competition and struggle between members of the same species and different species for food, space and other basic needs. 

3. Variations

        Within any population, there is a natural variation i.e. the individuals of same species vary in size, shape, behaviour and structure as compared to each other. 

4. Natural selection or the survival of the fittest

        In the struggle of existence, the individual who have more favourable variations will survive and others will perish. This sorting out of the individuals with useful variations by nature was called ‘natural selection’ by Darwin and ‘survival of the fittest’ by Wallace. 

5. Inheritance of variations
        The individuals after their natural selection pass on their useful variations to the next generations. 

6. Formation of new species

        These variations accumulate in new generations and after a number of generations these become so prominent that a new species with modified characters is formed.


ORGANIC EVOLUTION
 The word organic evolution is made up of two words ‘organic’ which means ‘living organisms’ and ‘evolution’ which means ‘unfold’. So, organic evolution is the unfolding of the process of formation of different types of organisms. As we see that there are millions of different types of animals and plants around us. All these forms of life came into existence from very simple unicellular organisms such as blue green algae which were produced in the oceans. With the passage of time these unicellular organisms modified themselves so that they can adapt themselves with the changing environment. These modification or variations were then passed on to the next generations, which resulted in the formation of new species of organisms. Thus according to the concept of organic evolution, the present day animals and plants have been evolved by a process of gradual change in the earlier simple forms of life, which took place in millions of years. This process of evolution is very slow and it is going on still today. But due to its slow rate we are not able to observe it. 

Evidences for Organic Evolution

 The concept of organic evolution is not a hypothetical concept. It can be proved by taking some evidences which indicates the occurrence of organic evolution. These evidences are: 

1. Homologous organs
2. Analogous organs
3. Fossils
4. Embryology

1. HOMOLOGOUS ORGANS

Homologous organs may be defined as the organs of different animals which have similar basic structure but different functions. For example, the flippers of a whale, the forelimbs of a frog and man have the same basic structures but they perform different functions, hence these are called homologous organs.

2.  ANALOGOUS ORGANS

Analogous organs are the organs of different animals which have different basic structure but perform same function. For example, the wing of a bird and the wing of a butterfly have different structures but they perform similar function so they are analogous organs.

3. FOSSILS

Fossils are the remains of dead bodies of prehistoric plants and animals. These provide good evidence for the organic evolution. Archaeopteryx is its best example. This animal has both the characters of reptiles and birds. Archaeopteryx had feathered wings like those of birds but possessed claws on the wings like reptiles. It also had a beak like birds but also had teeth like reptiles. This suggests that birds have evolved from reptiles.

4. EMBRYOLOGY

Embryology is the study of the development of the embryo of an animal. It also provides evidence for the evolution of organisms. For example, if we carefully observe the embryos of vertebrate animals like fish, tortoise, chick, rabbit and man. We will find out that all of them resemble to each other  

in their initial stages of development to such an extent that it becomes difficult to distinguish them from each other.

Sourse :- www.nrsciencecentre.blogspot.com and funny science

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Presentation ( FA-3 , 10th std Biology )

Asexual Reproduction in Plants

Plants can reproduce asexually, without the fertilization of gametes, by either vegetative reproduction or apomixis.

Natural Methods of Asexual Reproduction

Natural methods of asexual reproduction include strategies that plants have developed to self-propagate. Many plants, such as ginger, onion, gladioli, and dahlia, continue to grow from buds that are present on the surface of the stem. In some plants, such as the sweet potato, adventitious roots or runners (stolons) can give rise to new plants. In Bryophyllum and kalanchoe, the leaves have small buds on their margins. When these are detached from the plant, they grow into independent plants; they may also start growing into independent plants if the leaf touches the soil. Some plants can be propagated through cuttings alone.

Runners: asexual reproduction: A stolon, or runner, is a stem that runs along the ground. At the nodes, it forms adventitious roots and buds that grow into a new plant.

Artificial Methods of Asexual Reproduction

Artificial methods of asexual reproduction are frequently employed to give rise to new, and sometimes novel, plants. They include grafting, cutting, layering, and micropropagation.

Grafting

Grafting has long been used to produce novel varieties of roses, citrus species, and other plants. In grafting, two plant species are used: part of the stem of the desirable plant is grafted onto a rooted plant called the stock. The part that is grafted or attached is called the scion. Both are cut at an oblique angle (any angle other than a right angle), placed in close contact with each other, and are then held together. Matching up these two surfaces as closely as possible is extremely important because these will be holding the plant together. The vascular systems of the two plants grow and fuse, forming a graft. After a period of time, the scion starts producing shoots, eventually bearing flowers and fruits. Grafting is widely used in viticulture (grape growing) and the citrus industry. Scions capable of producing a particular fruit variety are grafted onto root stock with specific resistance to disease.

Grafting: Grafting is an artificial method of asexual reproduction used to produce plants combining favorable stem characteristics with favorable root characteristics. 

Cutting

Plants such as coleus and money plant are propagated through stem cuttings where a portion of the stem containing nodes and internodes is placed in moist soil and allowed to root. In some species, stems can start producing a root even when placed only in water. For example, leaves of the African violet will root if kept undisturbed in water for several weeks.

Layering

Layering is a method in which a stem attached to the plant is bent and covered with soil. Young stems that can be bent easily without any injury are the preferred plant for this method. Jasmine and bougainvillea (paper flower) can be propagated this way. In some plants, a modified form of layering known as air layering is employed. A portion of the bark or outermost covering of the stem is removed and covered with moss, which is then taped. Some gardeners also apply rooting hormone. After some time, roots will appear; this portion of the plant can be removed and transplanted into a separate pot.

Layering: In layering, a part of the stem is buried so that it forms a new plant.

Micropropagation

Micropropagation (also called plant tissue culture) is a method of propagating a large number of plants from a single plant in a short time under laboratory conditions. This method allows propagation of rare, endangered species that may be difficult to grow under natural conditions, are economically important, or are in demand as disease-free plants.

To start plant tissue culture, a part of the plant such as a stem, leaf, embryo, anther, or seed can be used. The plant material is thoroughly sterilized using a combination of chemical treatments standardized for that species. Under sterile conditions, the plant material is placed on a plant tissue culture medium that contains all the minerals, vitamins, and hormones required by the plant. The plant part often gives rise to an undifferentiated mass, known as a callus, from which, after a period of time, individual plantlets begin to grow. These can be separated; they are first grown under greenhouse conditions before they are moved to field conditions.

Courtesy:- Lumen Learning

PROJECT FA-3 ( 10th std- Biology )

How does smell affect Taste ?

We  know that we all have five senses: Taste, touch, smell, hearing, and sight. Even though the senses of taste and smell are separate, they are so close to one another that they are intertwined. Taste and smell work together to help you fully experience food.

http://www.nuclearconnect.org/wp-content/uploads/2013/03/senses.png

Have you ever had a cold and tried to eat your favorite food, only to find that it tastes relatively dull and boring compared to what it should taste like? Because your sense of smell is not as strong due to your stuffy nose, your sense of taste is also dulled. Why does this happen?



Let’s find out!



You have somewhere between 5,000-10,000 taste buds that detect tastants, the chemicals in your food that are sweet, salty, bitter, sour, or savory. The nerves in your taste buds then send messages along your cranial nerves to your brain.

While your taste buds are detecting tastants, a membrane along the roof of your nose is detecting odorants. The sensory cells along that membrane send messages olfactory bulb, which then combines that information with information from your taste buds to create the perception of flavor.

http://www.wysinfo.com/Perfume/picts/0_wysinfo-smell%20drawing2_550_1.JPG

http://www.tastescience.com/foodchartwhite.jpg

Your taste buds can detect five different tastes: sweet, sour, salty, bitter, and umami (www.innerbody.com). While your tongue tells you which category food is in, your sense of smell aids you in deciphering specific taste differences. When you take away your sense of smell, your brain has a much more difficult time determining the difference between specific tastes, especially if you cannot see the food!

Courtesy :- Discovery Express, Maddie Van Beek

Persentation ( FA -3 ,- 10th std physics ) Verification of ohm's Law

Objective: - To verify the Ohm's law.


Statement of Ohm's Law:


Ohm’s law states that at a constant temperature, current 'I' through a conductor between two points is directly proportional to the potential difference or voltage 'V', across the two points. That is,
                       V = IR
                           where R = constant
                                                                                       
                  Thus, the ratio V : I is a constant. This constant is called as the resistance (R) of the conductor.
GRAPH

After performing experiment for different readings of V & I and recording the observations, if we plot current on the x-axis of a graph and voltage on the y-axis of the graph, we will get a straight-line. The gradient of the straight-line graph is related to the resistance (R) of the conductor.

Related Theory:

Resistance:
•Resistance is the property of a component which restricts the flow of electric current. Energy is used up as the voltage across the component drives the current through it and this energy appears as heat in the component.
•Resistance is measured in ohms, the symbol for ohm is an omega(Ω).

Resistors connected in Series:

When resistors are connected in series their combined resistance is equal to sum of thier the individual resistances. For example if resistors R1 and R2 are connected in series their combined resistance, R, is given by:

R = R1+R2

Resistors connected in Parallel:

When resistors are connected in parallel their combined resistance is less than any of the individual resistances. Equation for the combined resistance R of 2 resistors R1 and R2 connected in parallel is given by:

1/R = 1/R1 + 1/R2

Sourse :- www.nrsciencecentre.blogspot.com
© NRSC, Model Prepared by Engineer Affan Nomani, Research Scholar & Writer

Courtesy:- online Labs

FA-3 project ( 10th std. physics )

Take a battery and measure the potential difference . Make a circuit and measure the potential difference when the battery is connected in the circuit. Is there any difference in potential difference of battery  ?

Let us consider the voltmeter, battery, switch, fuse and Bulb for measuring battery voltage.

Experiment -1.  In this  Diagram only battery is connected to the voltmeter
which  used to determine the voltage (electrical pressure) present at battery as shown in figure below:- 

Experiment- 2.  In this Diagram voltmeter is connected with circuit in which different electrical equipment is connected to tether as shown in figure below:- 

Connecting one lead of the voltmeter to the input side of a bulb and the other lead to earth results in a reading of the voltage present at the Bulb. Voltmeters are mostly used to measure voltages across components. They are connected in parallel with 

the component.

Result :- From the above two experiment we have observed that we measured the voltage from single battery only in 1st experiment while in second experiment we measured the voltage across  the circuit.
In 1st experiment directly we measured the voltage from battery when we measured voltage from circuit we found the less voltage of same battery which is connected with circuit because many loads are connected.

Sourse :- www.nrsciencecentre.blogspot.com

© NRSC, Model Prepared by Engineer Affan Nomani, Research Scholar & Writer

We and Our Science and Technology in modern age- Engineer Affan Nomani

Engineer Affan Nomani, Research Scholar and Columnist ,
 addressess the students on
" Science and Technology Modern age  "

It is an exciting age of science and technology in which we live. If these great achievement are used properly we can build a world free hunger, oppression disease and privation. But it is a big ' if '.

Our consciences seem to be dulled by crimes and outrages. In the last war the scientific achievement were destroyed into manifestations of horror. It is the violence in our hearts that accounts for great wars. Man himself is the present crisis. He is the greatest danger. 

If we take along view of human evolution we will find that man has grown through tenderness, compassion and endurance and not through anger, greed and passion. 

Engineering Education should undergo significant changes. You must emphasize not merely quantity but quality. People will put up with any amount of frustration If we use well the resources available, material and monetary. We may perhaps have to tighten up administration. 
Inadequate government policy and weak administration impede progress and development as much as lack of capital and inefficient methods of production. 

Building the India of tomorrow, harnessing our water resources, keeping the lines of communication open, building the defences of the country. 
The progress of mankind is dependent on the increasing use of our materials. But nature resources are limited so we need to develop the new technology.

PRESENTATION ( Biology ) :- Presence of starch in leaves

TITLE:-  Presence of starch in leaves
AIM:-  To Show Presence of starch in  leaves.

MATERIAL REQUIRED:- 1. Beaker  2. Test  tube , 3. Bunsen burner. 4. water bath 5. Ethanol  6. Tripod stand 
                                           7.  leaf

PROCEDURE:-  let us consider Beaker , Test  tube ,  Bunsen burner,  water bath ,  Ethanol ,Tripod stand and leaf as shown in figure .

fig:- boiling the leaf in ethanol spirit

fig:- Iodine test

 Let us take a leaf from a plant with soft and thin leaves and well exposed  to sun light.
* boil the leaf in methylated spirit removal of chlorophyll.
*take the leave carefully  from test tube by using a brush.
*spread the leaf in Petridish add few drops of betadine solution on it. Again observe leaf. 

PRECAUTION:-  we have done the experiment carefully.

RESULT:-  As per their activity above we observe that presence of starch in leaf.

© NRSC, Model Prepared by Engineer Affan Nomani, Research Scholar & Writer

PROJECT ( Biology ):- Oxygen is produced during photosynthesis in the presence of light.

TITLE:-  Oxygen is produced during photosynthesis in the presence of light.

AIM:-  To Show oxygen  is produced during photosynthesis in the presence of light.

MATERIAL REQUIRED:- 1. Beaker  2. Test tube 3. Water  4. Funnel  5. Hydrilla Plant.

PROCEDURE:-  Let us consider 1. Beaker  2. Test tube 3. Water  4. Funnel and  5. Hydrilla Plant as shown in figure below. 

*  place some water plant like hydrilla in a funnel and keep it in a beaker.
* Then pour the water in the beaker.
*  Invert a test tube full of water over the stem of a funnel.
*  place on apparatus in the sun and the other in the dark for at least 2-3 hours. You would seed that in place       of water there is a air that fills in the set up kept in sun . It is actually a gas that will be collected in the test        tube.
*  observe the other set up kept in dark.
*  we found that difference in the amount of gas collected.

PRECAUTION:-  we all group members have done the experiment carefully.

RESULT:-  when we tested the gas in the test tube by interesting a glowing match stick or insence stick which would burst into flames. This shows the presence of oxygen.

© NRSC, Model Prepared  by Engineer Affan Nomani, Research Scholar & Writer

PROJECT:- Concept of Light and Ray Diagram For Concave Mirror.

Q.No.1. Write a notes on concept of Light with the views of prominent scientists in scientific domain. 

Answer:-  The view of world's prominent scientists on light are different. Someone consider light is a particle while someone consider light is a wave. The debate about whether light consists of waves or particles dates back to the 17th century  Early in the 20th century, Albert Einstein , Niels Bohr, and others exploring the world of quantum mechanics said light behaves as both waves and particles. Later experiments clearly showed this "wave-particle duality," but they were never able to show light as both waves and particles at the same time. The authentic definition of light is that it is a type of energy and Its  a form of electromagnetic radiation of a  wave length which can be detected by the human eye. The study of light, known as optics, is an important research area in modern physics. Light is electromagnetic radiation that is shows properties of both waves and particles .

Research Scholar and columnist Engineer Affan Nomani has written in his article on June 28, 2016 , published in India's national English, Hindi and Urdu newspaper and magazine  that " Abu Ali Muhammed Hasan Ibne Haisam ( 965-1039 BC ) , well known as  Al-Hazen in Europe , was the first Scientist who proved Theology of European Wrong and given wonderful theory that the Light rays comes  from object to the Eye not from Eye to the object.  Al-Hazen was the one of the world's most influential physicist ,
responsible for the development of world's first Microscope.


Q.No.2. When an object placed at centre of curvature

 then where and what kind of image will be form ?


Answer:-  When an object placed at centre of curvature  ( C ) then the image will be formed Real, Inverted  and same that of object at centre of curvature ( C )  only.

Q.No.3. Where will be the image be formed when we 
place an object on the principal axis of a concave mirror at a point between focus and centre of curvature  ? 

Answer:- When an object placed at between focus
 ( F )  and centre of curvature ( C )  then the image will be formed Real, Inverted, Enlarged and beyond the centre  of curvature  ( C ).

Q.No.4  When an object placed at beyond centre of

curvature ( C )  then where and what kind of image 

will be form ?

 
Answer:- When an object placed at beyond the centre of curvature ( C )  then the image will be formed Real, Inverted, and diminished at 
between focus ( F )  and centre of curvature ( C ).

© NRSC, Model Prepared by Engineer Affan Nomani, Research Scholar & Writer