X BIOLOGY : REPRODUCTION IN FLOWERING PLANT..

REPRODUCTION IN FLOWER..

http://www.youtube.com/watch?v=FsBQQDg5GIw

X BIOLOGY : REPRODUCTION

VEGETATIVE PROPAGATION IN PLANTS..

http://www.youtube.com/watch?v=GNnkYTQBlRo

[TED TALKS] Beau Lotto + Amy O’Toole: Science is for everyone, kids included

What do science and play have in common? Neuroscientist Beau Lotto thinks all people (kids included) should participate in science and, through the process of discovery, change perceptions. He's seconded by 12-year-old Amy O'Toole, who, along with 25 of her classmates, published the first peer-reviewed article by schoolchildren, about the Blackawton bees project. It starts: "Once upon a time ... " Link on TED

X CHEMISTRY : CHEMICAL BONDS..

CHEMICAL BONDS..

http://www.youtube.com/watch?v=KjoQHqgzda8

X PHYSICS : REFLECTION OF LIGHT..

REFLECTION OF LIGHT..

Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection.A mirror provides the most common model for specular light reflection, and typically consists of a glass sheet with a metallic coating where the reflection actually occurs. Reflection is enhanced in metals by suppression of wave propagation beyond their skin depths. Reflection also occurs at the surface of transparent media, such as water or glass.

In the diagram , a light ray PO strikes a vertical mirror at point O, and the reflected ray is OQ. By projecting an imaginary line through point O perpendicular to the mirror, known as the normal, we can measure the angle of incidence, θi and the angle of reflection, θr. The law of reflection states that θi = θr, or in other words, the angle of incidence equals the angle of reflection.
Laws of reflection :
If the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:
The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane.
The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal.
The reflected ray and the incident ray are on the opposite sides of the normal.
Multiple reflections :
When light reflects off a mirror, one image appears. Two mirrors placed exactly face to face give the appearance of an infinite number of images along a straight line. The multiple images seen between two mirrors that sit at an angle to each other lie over a circle.The center of that circle is located at the imaginary intersection of the mirrors. A square of four mirrors placed face to face give the appearance of an infinite number of images arranged in a plane. The multiple images seen between four mirrors assembling a pyramid, in which each pair of mirrors sits an angle to each other, lie over a sphere. If the base of the pyramid is rectangle shaped, the images spread over a section of a torus.Light bounces exactly back in the direction from which it came due to a nonlinear optical process. In this type of reflection, not only the direction of the light is reversed, but the actual wavefronts are reversed as well. A conjugate reflector can be used to remove aberrations from a beam by reflecting it and then passing the reflection through the aberrating optics a second time.

source : http://en.wikipedia.org/wiki/Reflection_(physics)

X CHEMISTRY: CARBON AND ITS COMPOUNDS.

CARBON AND ITS COMPOUNDS

OVERALL VIEW...

http://www.youtube.com/watch?v=Kjn5Ht0Vn30

X PHYSICS :MAGNETISM

MAGNETISM vs. ELECTRICITY..

PLEASE FEEL FREE TO ASK QUERIES..

http://www.youtube.com/results?search_query=magnetism+and+electricity&oq=magnetism+&gs_l=youtube.1

.1.0l10.16444.16444.0.21018.1.1.0.0.0.0.193.193.0j1.1.0...0.0...1ac.tdLrZVjAhd8

X BIOLOGY: CONTROL AND CO-ORDINATION

SPINAL CORD AND REFLEX ACTION

http://www.youtube.com/results?search_query=reflex+action&oq=reflex&gs_l=youtube.1.0.0l10.8712.10455.0.14107.6.6.0.0.0.0.274.974.2j1j3.6.0...0.0...1ac.voHwnrrQm2M

Class X: Important Questions (Previous years board exams questions)

Chapter 1: Chemical Reaction and Equations
source|jsuniltutorial : Solved questions 1
source|jsuniltutorial : Solved questions 2
source|jsuniltutorial : Solved questions 3

Very short answer type questions:
1. Balance the chemical equation:
NaOH + H₂SO₄ ---> Na₂SO₄ + H₂O
Ans: 2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O 

2. What is chemical formula of Rust?
Ans: Fe₂O₃.xH₂O  

3.  Write chemical formula of quick lime?
Ans: CaO

4. What is the chemical name of Lime?
Ans. Calcium Oxide

5. In the refining of silver, the recovery of silver from silver nitrate solution involves displacement by copper metal. Write down the reactions involved.
Ans. When copper is mixed in silver nitrate solution, it displaces the silver because copper is more reactive than silver.
2AgNO₃ + Cu ---> Cu(NO₃)₂ + 2Ag



Further only questions are given. Students can comment for answers if they want to.

6. Give an example of a double displacement reaction.
7. Write chemical equation representing reaction between lime and water.
8. What happens when limestone is heated vigorously?
9. Identify the substances that are oxidized and the substances that are reduced in the following reactions:
4Na(s) + O₂ ---> 2Na₂O(s) and CuO(s) + H₂(g) ---> Cu(s)H₂O(l)

Chapter 2: Acids, Bases and Salts
source|jsuniltutorial : Notes
source|jsuniltutorial : Solved questions 1
source|jsuniltutorial : cbse guess questions
source|jsuniltutorial : Important questions

Chapter 6: Life Processes
source|jsuniltutorial : Important questions 1
source|jsuniltutorial : Important questions 2

Chapter 12: Electricity
source|jsuniltutorial : Important questions 1
source|jsuniltutorial : Important questions 2
source|jsuniltutorial : Important questions 3 (MCQ)

Solved board question papers:
source|www.tcyonline.com

JUST FOR KNOWLEDGE...

1.WHAT IS SUBSTATION???
European sockets provide electric current at 230 Volts.Since, this voltage do not suffice to cover the large distance from power plant to our homes, it is raised in the power plants with the help of transformers up to 380,000 Volts.Locally, large substations or 'small transformer houses' transform to 230 Volts.A transformer is like the electromagnet.The incoming high voltage electric current generates a magnetic effect in the coil.This permeates the neighboring coil in the second electric current and generate a lower voltage: 230 Volts...

2.DO YOU KNOW???

• The Electric eel generates up to 600 Volts of Electricity in special muscles.In this way it can defend its enemies.
• Voltages starting from 48 Volts are considered fatal.Hence, Electric toys should have a maximum voltage of 24 Volts.
• Power saving lamps can last 8 times longer than normal bulbs and consume only about one-fourth of the electricity.

Source :
'1.' taken from  Knowledge Encyclopedia by Oxford (2012) page: 110
'2.' taken from  Knowledge Encyclopedia by Oxford (2012) page: 111

CLASS X PHYSICS : POWER

PHYSICS

WORK AND POWER

SOURCE :http://www.youtube.com/watch?v=mK0FUxGKsG4

SO EASY PERIODIC TABLE!!!!!!!!

                                
                                     SOURCE: http://www.youtube.com/watch?v=-jU4DIUok2A

X PHYSICS (ELECTRICITY) RESISTORS...

ELECTRONICS-RESISTORS.....

SOURCE :http://www.youtube.com/watch?v=HrZZMhWZiFk&feature=context-vrec

PHYSICS X: ELECTRICITY

RESISTANCE  AND  RESISTIVITY

http://www.youtube.com/watch?v=qSixX3YWpUs
BY :Raghvi Rumpal.

CHEMISTRY: ACIDS,BASES AND SALTS

ACIDS, BASES AND SALTS

source http://www.youtube.com/watch?v=qSixX3YWpUs

CLASS X :PHYSICS CHAPTER:Electricity and Circuits

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.....................

source: http://www.youtube.com/watch?v=D2monVkCkX4

CLASS X BIOLOGY CHAPTER:LIFE PROCESSES : Photosynthesis (Light Reactions)

WATCH IT.........................!!!!

                                  SOURCE:  http://www.youtube.com/watch?v=hj_WKgnL6MI

Human Digestive System

Amazing to know how our body's digestive system works everyday. Check out the video:

ASTHMA a respiratory disease

Asthma is a chronic lung disease characterized by chest tightness, shortness of breath, coughing and wheezing.  With asthma, a blockage of airflow in and out of the lungs occurs from muscle squeezing, swelling and excess mucous.  Between 12-15 million people in the United States have asthma, including up to 5 million children.
Physicians who are not specialists in this disease may mistake its symptoms for an infection, unaware that the underlying problem is asthma.  Asthma is characterized by three airway problems:  obstruction, inflammation and hyper responsiveness.  Asthma patients respond to environmental factors differently than non-asthmatics.  In response to a trigger, the asthmatic's airways become narrowed and inflamed, which results in wheezing, coughing and tightness in the chest.  If you have asthma, you can minimize symptoms by avoiding these triggers, and by working with your doctor to develop an effective plan for treatment.

Triggers for Asthma

Asthmatic symptoms can be triggered by several factors, including:

• Allergens or irritants
• Exercise
• Medications or foods
• Viral or sinus infections
• Reflux disease
• Emotional anxiety

Managing Asthma

Because asthma is a chronic disease, it requires careful monitoring and effective treatment.  The treatment of asthma has four main components

• The use of objective measures of lung functions to assess the severity of asthma and to monitor treatment (peak flow meters and spirometers)
• Environmental control measure to avoid or eliminate factors that trigger asthma symptoms or flare-ups
• Medication therapy for long-term management to reverse and prevent airway inflammation as well as therapy to manage asthma flare-ups
• Patient education to foster a partnership between the patient, his family and the physician

According to the Guidelines, there are six goals for the effective management of asthma:

• Prevent chronic and troublesome symptoms
• Maintain (near) ?normal? breathing
• Maintain normal activity levels, including exercise
• Prevent recurrent asthma flare-ups, and minimize the need for emergency room visits or hospitalizations
• Provide optimal medication therapy with no or minimal adverse effects
• Meet patients' and families' expectations of satisfactory asthma care

With proper diagnosis, monitoring and treatment, individuals with asthma can engage in regular physical activity and can live normal healthy lives.

For more information

Contact the American Academy of Allergy, Asthma and Immunology

TEXT SOURCE: http://www.healthchecksystems.com/asthma.htm
VIDEO SOURCE: http://www.youtube.com/watch?v=7EDo9pUYvPE

CLASS X BIOLOGY CHAPTER: LIFE PROCESSES... Working of our body during respiration...........

 Watch it.................................>


SOURCE:- http://www.youtube.com/watch?feature=player_embedded&v=o2OcGgJbiUk#!

CLASS X BIOLOGY CHAPTER: LIFE PROCESSES...

LIFE PROCESSES : RESPIRATION

In physiology, respiration (often confused with breathing) is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction. This is in contrast to the biochemical definition of respiration, which refers to cellular respiration: the metabolic process by which an organism obtains energy by reacting oxygen with glucose to give water, carbon dioxide and ATP (energy). Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the bulk flow and transport of metabolites between the organism and the external environment.

In unicellular organisms, simple diffusion is sufficient for gas exchange: every cell is constantly bathed in the external environment, with only a short distance for gases to flow across. In contrast, complex multicellular animals such as humans have a much greater distance between the environment and their innermost cells, thus, a respiratory system is needed for effective gas exchange. The respiratory system works in concert with a circulatory system to carry gases to and from the tissues

ORGAN       OXYGEN CONSUMPTION(ml Oxygen/min per 100 g)

Heart(rest)                                  8

Heart(heavy exercise)                 70

Brain                                           3

Kidney                                        5

Skin                                           0.2

Resting skeletal muscle               1

Contracting skeletal muscle        50



src :http://en.wikipedia.org/wiki/Respiration_(physiology)

Human Circulatory System!

Human Circulatory System

CLASS X SEM 1 SYLLABUS

QUADDo Science welcomes you all in New session.
so here is the syllabus of Class X of Science :
Chemistry :
1. Chemical reactions and equations
2. Acids, Bases and Salts.
3. Metals and Non metals
Physics :
12. Electricity
13. Magnetic effects of Electric current.
Biology :
6. Life processes
7. Control and Coordination

IMPORTANT BOARD QUESTIONS OF CHAPTER :NATURAL RESOURCES IX

IMPORTANT POINTS FROM CHAPTER : NATURAL RESOURCES...

NATURAL RESOURCES :

POINTS TO REMEMBER..

NITROGEN FIXING BACTERIA :

• AZOTOBACTER : bind Atmospheric Nitrogen and helps in Ammonification.
• DIAZOTROPHES : helps in changing nitrogen to ammonia.

         Types of Diazotrophes -

          (A) Free Living -

                Anaerobes, Aerobes, Bacillus Polymyxa, Anabaena Cylindrica

          (B) Symbiotic -

                Cyanobacteria, Rhizobia, Frankias

source : http://en.wikipedia.org/wiki/Nitrogen_fixing_bacteria

http://en.wikipedia.org/wiki/File:Soybean-root-nodules.jpg

IMPORTANT DIAGRAMS FROM KINGDOM ANIMALIA- IX Diversity in living organisms (Updated on :25.02.12)

IMPORTANT DIAGRAMS FROM ANIMALIA KINGDOM :

(Earth worm, Cockroach, Birds and Bony Fish)

1. Earthworm :

Earth worm excrete out the extra material through the Anus.

It shows the burrowing adaptations.

2. Cockroach :

3. Bony Fish :

4. Birds :

Birds belong to Phylum Chordata, Sub Phylum Vertebrata and Class Aves.

Streamlined body to provide minimum resistance to air currents and helps in flying.

Forelimbs modified into wings and Feathers provide insulation to the body.

Hind limbs modified for walking, perching and swimming.

Pneumatic bones (hollow bones)  reduce the weight of the body and helps in flying.

Eyes covered with Nictitating membrane.

Lung shows air sacs attached to it.

SOURCE : SOUVENIR LAB SKILLS BOOK IX AND CD.

if any queries, please comment...

QUESTION ANSWERS- IX Diversity in living organisms (Updated on :16.02.12)

SHORT QUESTIONS :ANIMALIA...
(related to Pisces, Earthworm and Cockroach)

1. To which Phylum does the Earthworm belong?
Ans. Annelida

2. What is the scientific name of the Earthworm?
Ans. Pheretima

3. What is Prostomium?
Ans. The small sensory lobe which is on the mouth of the Earthworm.It is present on the first segment of the body.

4. To which Phylum does the Cockroach belong and what is its scientific name?
Ans. Arthropoda, Periplanata

5. How is the body of the Cockroach differentiated ?
Ans. It is divided in 3 parts : Head , Thorax and abdomen.Head is triangular in shape and bears two compound eyes and the Antennae which are also called the sensory organ.

6. How does the exchange of the gases takes place in Cockroach?
Ans. Through Spiracles.

7. To which class does fish belong to?
Ans. Osteichthyes

8. Which organs helps in the locomotion of the fish?
Ans. Dorsal, Pelvic, Pectoral and Tail fins
Dorsal and Pelvic helps in balancing and movement in water.Pectoral fins acts as brakes and Tail fins helps in changing the direction.

9. By which membrane are the eyes of the fish (bony) protected?
Ans. Nictitating membrane by which eyes of the bony fish are covered which protect its eyes from water.

10. Why Earthworm called the 'Farmers Friend'?
Ans. This is because of its burrowing habits as it acts as Nature's plough man and their castings act as manure.


SOURCE :SOUVENIR IX SCIENCE LAB SKILLS

QUESTION ANSWERS (Class IX) :Why do we fall ill? - (UPDATED ON: 11.02.12)

On the reader's request we are posting the Que-Ans of the chapter :Why do we fall ill? We will continue the chapter : Diversity in Living Organisms after these posts.

Que - Ans :
1. Define Health.
Ans. According to WHO (World Health Organisation) , It is the state of complete physical, mental and social well being.


2. What is Disease ?
Ans. Anything which interferes with the normal functioning of the body and impairs the health.


3. Differentiate Congenital Diseases from Acquired ones.
Ans. Congenital :
a. These occur since from birth.
b. inherited from the parents to the offspring. 
Acquired :
a. It occurs during the lifetime of the person and not from the birth.
b. It does not get inherited.It occurs due to pathogens or due to deficiency of nutrients, hormonal imbalance or due to degeneration of the tissues.

4. What is Incubation Period?
Ans. It is the period between the infection and the appearance of the first symptom.


5. Name the diseases which are caused by :
a. Bacteria : TB, Typhoid, Anthrax and Tetanus
b. Viruses : Common Cold, AIDS, Dengue fever and Mumps.
c. Fungi : Ring worm, Skin infections and Athlete's foot
d. Protozoa : Malaria, Kala Azar, Sleeping Sickness and Amoebiais

6. Important points :
a. Malaria is spread by the mosquito Anopheles
b. Mosquito Culex spread Filaria.
c. AIDS is caused by the Retrovirus HIV.
d. A dengue is the Virul disease caused by a day time biting of the mosquito called Aedes
e. TB is caused by a bacterium Mycobacterium Tuberculosis.
f. Typhoid is caused by Salmonella Typhi.
g. Leishmania Donovani is the protozoan which causes Kala azar (black fever)
h. Helicobacter pylori is a small curved shaped bacteria which is responsible for the peptic ulcers.

7. Which was the first Anti biotic?
Ans. Penicillin which was invented by Alaxander Flamming in 1928.


8. Name the Organs which are targeted by specific diseases :
a. Hepatitis : Liver
b. Fungal Diseases : Skin
c. Pneumonia : Lungs
d. TB : lungs
e. Diarrhoea : Intestines.


9. Which is the most common type of Plague?
Ans. Bubonic Plague.


10. Who discovered Vaccine for the first time and which one?
Ans. Edward Jenner invented the vaccine for the first time and it was of smallpox.


Readers can ask Questions  from the syllabus to clear their doubts regarding science exam.
SOURCE : NCERT SCIENCE AND DINESH BIOLOGY IX...

IMPORTANT QUESTIONS (X) ...!!!!

                                                 MCQ's

1. Four students A,B,C,D perform experiment on tracing the path of light ray through a glass slab. The position of the pins used to describe incident way is shown on paper by four of them, respectively as:

   

   'c' option is correct

   
   

   
   

   
   

   2)Teacher asked three students to write one precaution by each of them regarding the experiment on  tracing the path of the light ray through glass slab. First, second and third student wrote down the following precautions, respectively
    (a) While tracing emergent ray, we should see heads of pins.
    (b) One eye should be kept closed, while tracing emergent ray
    (c) Glass slab should have parallel edges.
          The correct statements are of
          (i) 1 and 2             (ii) 2 and 3                (iii) 1 and 3                 (iv) All three
   
   
          3) A student is asked to label his diagram made as observation on tracing the path of light ray 
             through glass slab as follows:
      
   The correct sequence of labelling angle I, angle e , angle r and lateral displacement respectively is,
   1. (a) 1,2,3 and 4                          (b) 3,4,1 and 2
      (c) 1,3,2 and 4                          (d) 3,2,4 and 1
      
      
      4) A student obtains an image of window by using a convex lens on a screen. He adjusts the position of screen to get sharpest and brightest image possible. To get focal length of lens he should measure the:
      (a) distance between window and screen
      (b) distance between convex lens and window.
      (c) distance between screen and convex lens
      (d) distance between window and convex lens as well as distance between window and screen.
       
   5)A student determines the focal length of a device 'X' by focusing the image of a distant object on a screen placed on the same side as the object. The device 'X' is.                                                       (a) Concave lens             (b) Convex lens     (c) Concave mirror           (d) Convex mirror   
2. 
   
   
   1. QUESTION / ANSWERS 
      Ques1: Name the part of the human eye that helps in changing the focal length of the lens?
      Ans: Ciliary Muscles
      
      
      Ques2:What is the cause of dispersion of white light passing through a prism? Which colour of light deviates the-
       (i) most ; (ii) least
      Ans: Each colour in VIBGYOR has different refractive index or speed in glass medium of prism. Red have least value of refractive index and violet has the maximum.                                                                                                                                                                                                                                                                                         Ques3: Why does the clear sky appear blue? How would the sky appear in the absence of earth's atmosphere?                                                                                                                Ans:Scattering of molecules of gases in atmosphere makes the colour of sky appear blue. In absence of atmosphere of earth no scattering will be there as a result sky will appear Black.                                                                                                                                                                                                                                                            Ques4: How can you identify three types of mirrors without touching?                                                                                                                                  Ans: By looking into mirror by going close to it. If image is of same size and erect then it is Plane mirror. If image is of bigger size and erect then it is Concave mirror. If image is of smaller size and erect then it is convex mirror.                                                                                                                                                                                                                                     
      Ques5: A real image, 1/5^th the size of object is formed at a distance of 18cm from a mirror. What is the nature of mirror? Calculate its focal length.                                                              Ans: Real image means it is concave mirror. m = -1/5 = -(-18)/u ==> u= -90                        Now use 1/f = 1/u + 1/v ==> f= -15                                                                                                                                                                                                                                    
      Ques6: A ray of light is incident obliquely on a glass slab. Draw a ray- diagram showing the path of the light ray. Clearly mark angle of incidence, angle of refraction, angle of emergence and lateral displacement of the ray. Give a formula to find refractive index of glass slab in terms of angle of incidence and angle of refraction.
      Ans:
       
                                                        
             
      Ques7: A person cannot see objects farther than 12m from the eye clearly. Name the,defect of vision he is suffering from and the lens that shouls be used for correction of this defect. Illustrate with the help of a diagrams, How this lens will correct the defective vision.
      Ans: 
      
        
      Ques8: Draw a ray diagram in each of the following cases to show the formation of image, when object is placed:
      (a) Between optical centre and principal focus of a convex lens.
      (b) Between F and 2F of a concave lens
      100. At 2F of a convex lens
      What can you say about sign and value of linear magnification ratio in, (i) and (ii) above.
                                                                                                                                                                                                                    
      Ques9: (i)Define real image of an object.
      2. Name the mirror that
         (a) can give real as well as virtual image of an object.
      (b) will always give virtual image of same size of an object.
      (c) will always give virtual and diminished image of an object.
      (d) is used by a doctor in examining teeth.
      (iii) With the help of a ray diagram explain the use of concave mirror as solar concentrators.
      Ans: (i) If reflected or refracted meet actually, the point of intersection is called real image of point object. (ii) (a) concave (b) plane mirror  (c) convex mirror     (d) concave
      
                                                
      Ray coming parallel to principal axis will pass through principal focus.
      
                                                                                                                   
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      

SOME IMPORTANT QUESTIONS (X) ..!!!!!

                                                   MCQ's 

           1) Four stages of binary fission in amoeba are shown below. This stage at which nuclear fission and 

              cytokineses are observed is ,stage   

 

(a) I                 (b) II                             (c) III                     (d) IV

2) To determine the percentage of water absorbed by the raisins, before final weighing of raisins after  being kept dipped in water for about two hours, extra water from the soaked raisins is removed by:

(a) dry cotton                 (b) filter paper            (c) hot air blower                     (d) silken cloth

1. 
   
   3) Out of the four slides I,II,III,IV whose details are shown below, which one would you focus under the microscope for observing budding in yeast?
   
   (a) I                          (b) II                       ( c) III                                   (d) IV
   
   
   4) The process represented in diagram below is the:
   
   (a) formation of spores in Amoeba
   (b) formation of bud taking place in Amoeba
   (c) identical gametes being formed in Amoeba
   (d) formation of daughter cells in Amoeba.
   
   
   5) A student soaked 5 grams of raisins in 25 mL of distilled water in each of two beakers A and B.  Beaker A was maintained at 25°C and beaker B at 50 °C. After one hour, the student observed that the water absorbed but the raisins was:
   (a) same in case of A and B                               (b) less in case of A than in B
   (c) exactly double in A, of that in B                    (d)exactly four times in A, of that in B
   
   
   6)A student was given two slides, one of the budding in yeast and the other of binary fission in amoeba. He was asked to identify any one difference in the nucleus of the two. He observed both the slides and identified correctly____
   (a) presence of two distinct nuclei in amoeba, one in yeast and two in bud.
   (b) presence of one nucleus in amoeba, two in yeast and one in its bud
   (c) presence of single nucleus each in amoeba and yeast cell and none in the attached bud.
   (d) presence of two nuclei in the centrally constricted amoeba, one in yeast cell and one in its bud.
   
   
                                  QUESTION/ANSWERS 
   Ques1: Select the biodegradable wastes from the following:
               DDT, Crop's residue, Leather and glass
   Ans: Crop's residue and leather 

 Ques2: In a food chain consisting snake, insect, grass and frog, assign an appropriate trophic level   to  frog.  Ans: Grass--> insect--> frog-->snake (Third Trophic Level)

  Ques3: Name those parts of a flower which serve the same function as the following do in animal:

                    (i) Testis (ii) Ovary (iii) Eggs (iv) Sperms  

                           Testis = Anther

                           Ovary = Ovary 

                           Eggs = Oules 

                           Sperms = Pollen ( Pollen Grains)  

  Ques4: What are fossil fuels? How are they formed?

   Ans:  Write the definition and formation of fossil fuels.

  

 Ques5: What is ozone? How does it protect the organisms on the Earth?

 Ans: Ozone is O_3. It forms a protective blanket over the earth's atmosphere and it's depletion causes harmful effects on humans. It absorbs the UV radiations coming from sun.

      

Ques6: What are sexually transmitted diseases? Name an STD which damages the immune system of  the human body?

Ans: Sexually transmitted diseases are diseases that spread through sexual contact.

               AIDS is the STD which damages the immune system of  the human body.

      

Ques7: Distinguish between analogous organs and homologous organs. Identify the analogous organs and homologous organs among the following:

Wings of an insect, wings of a bat, forelimbs of a frog, forelimbs of a human.

Ans: Homologous - organs having similar origin and structural plan but perform different functions.

        Analogous - organs having dissimilar origin and structural plan but perform same functions.

        Homologous organs: Forelimbs of frog and human

        Analogous organs: Wings of insect and bat.

Ques8:Study the given data and answer the questions that follow:

1	2	3
Parental plant cross fertilized and seeds collected	F1 Generation offsprings.	F2 Generation offspring after self pollination of F1 hybrid.

Male parent- Round Green seeds Female parent-Wrinkled Yellow seeds

All seeds- Round yellow

314-Round yellow 110-Round green 102-Wrinkled yellow 32-Wrinkled green

(a) What is the term given in this type of cross?

(b) What does the data in column 2 indicate?

State how did you arrive at this conclusion.

 Ans:  (a) Dihybrid Cross

          (b) Round shape and yellow colour in pea plants are dominant triats.

Ques9: What is the importance of DNA copying in reproduction? Why is variation beneficial to the species but not necessary for the individual? Explain.

Ans: DNA copying is essential part of reproduction because it ensures that same blue print of body design is maintained. Variation of the species is beneficial for adaptation and better survival. It may result in formation of blue species.

Ques10:(a) What is the role of seminal vesicles and the prostate gland?

              (b) What are the three categories of contraception methods? Write briefly about each.

Ans: (a)  Seminal vesicles-secrete the white substance which acts as lubricant , nutritive and    transport it. 

              Prostate gland- its secretion provides the medium for sperms to move.

        (b) 3 categories for contraception:

             Mechanical Barrier, Harmonal or Chemical Method , Surgical method.

Ques11: Draw longitudinal section of a flower and label on it following:

1. Ovary (ii) Style (ii) Stigma (iv) Anther

Why is vegetative propagation practised for growing some plants? Give two examples of plants grown by this method.

Ans:

 Vegetative propagation is used for growing some plants which do not produce viable seeds.

(give any two examples)