CLASS 8 HOLIDAY HW AND WORKSHEET.

* LEARN THE Q & A OF CELL STRUCTURE AND FUNCTION.

* PRACTICE THE DIAGRAMS.

* LEARN TWENTY ELEMENTS NAME AND THEIR SYMBOLS, SOME COMMON COMPOUNDS AND VALENCY TABLE.

* COMPLETE THE WORKSHEET.

1. A ball of dough is rolled into a flat chapatti. Name the force exerted to change the shape of the dough.

 2. Where do we apply a force while walking?

3. A girl is pushing a box towards east direction. In which direction should her friend push the box so that it moves faster in the same direction?

4. A gas filled balloon moves up. Is the upward force acting on it larger or smaller than the force of gravity?

5. Does the force of gravitation exist between two astronauts in space?

6.Read the following statements and write the appropriate term against each statement.

A. I control the functions of a cell. Who am I? ...................

 B. I am like a policeman. I do not allow anything and everything to get in and out of the cell. Who am I? ...................

 C. I transfer characters from parents to offsprings. Who am I?

7.Classify the following terms into cells, tissues and organs and write in the tabular column given below.

 RBC, WBC, Nerve cell, blood, muscle cell, blood vessels, brain, heart, hand, stomach,bone,kidney, skin.

8.Fill in the blanks with the terms given in the box below: Nucleus, chromosomes, cell wall, cell membrane, protoplasm, cytoplasm, ribosome, cell organelles

The outermost layer of plant cells is the (a)---------------- beneath which is the (b)------------------------ . The term (c)-------------------- refers to the jelly-like substance containing all the (d)--------------------------- . The (e)------------------- contains thread-like structures called (f)------------------- .(g)---------------- involved in protein synthesis.

CLASS 7 HOLIDAY HOMEWORK AND WORKSHEET

* LEARN THE Q & A OF NUTRITION IN PLANTS AND HEAT AND TEMPERATURE.

*LEARN  THE FIRST TWENTY ELEMENTS AND THEIR SYMBOLS, NAME OF THE COMMON COMPOUNDS AND VALENCY TABLE.

* COMPLETE THE WORKSHEET.

1.Can you give me a name? Solve each of the following riddles by writing the name of the organism and its mode of nutrition. One riddle is solved to help you.

 (a) I am tall but I cannot move. I am green and can prepare my own food.

 tree, autotroph

(b) I live in water; people keep me in an aquarium and feed me.

 (c) I am small and I can fly. I disturb your sleep, bite you and suck your blood which is my food. ,

 (d) I am white and soft. I grow well in the rainy season. Children pluck me from the ground and admire me. I absorb nutrients from decomposed dead parts of plants and animals in the soil.

2.Fill in the blanks of the paragraph given below with the words provided in the box. chlorophyll, energy, food, carbon dioxide, water, photosynthesis Note: A word can be used more than once.

 Leaves have a green pigment called (a)------------- which captures (b)----------- from sunlight. This (c)------------- is used in the process of (d)----------- and along with other raw materials like (e)------------ and (f) ---------------synthesize (g)-------------- .

3.At a camp site there are tents of two shades – one made with black fabric and the other with white fabric. Which one will you prefer for resting on a hot summer afternoon? Give reason for your choice. Would you like to prefer the same tent during winter?

4.Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why.

5.To keep her soup warm Paheli wrapped the container in which it was kept with a woollen cloth. Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer.

CLASS 6 HOLIDAY HOMEWORK AND WORKSHEET.

* LEARN QUESTION AND ANSWER OF COMPONENTS OF FOOD, AND SORTING MATERIALS INTO GROUPS.

*LEARN THE FIRST TEN ELEMENTS AND THEIR SYMBOLS.

* COMPLETE THE GIVEN WORKSHEET.

1.Arrange the jumbled words to arrive at the appropriate names of materials and also write two uses of each.

 (a) milaunuim   (b) tcaslpi   (c) soekrnee   (d) gavnier

2.Which among the following materials would you identify as soft materials and why? Ice, rubber band, leaf, eraser, pencil, pearl, a piece of wooden board, cooked rice, pulses and fresh chapati.

3.On a bright sunny day, Shikha was playing hide and seek with her brother. She hid herself behind a glass door. Do you think her brother will be able to locate her. If yes, why? If no, why not?

4.Unscramble the following words related to components of food and write them in the space provided.

 (a) reinpot __________

 (b) menliars __________

 (c) tivanmi __________

 (d) bocatradhyer __________

 (e) nitesturn __________

 (f) tfa

5.Fill in the blanks from the list of words given below:

 (carbohydrate, fat, protein, starch, sugar, Vitamin A, Vitamin C, roughage, balanced diet, obesity, goitre )

 (a) Egg yolk is rich in ____________ and egg albumin is rich in __________.

(b) Deficiency diseases can be prevented by taking a ___________.

(c) Eating too much of fat rich foods may lead to a condition called ____________. (d) The component of food that does not provide any nutrient to our body and yet is essential in our food is ___________.

6.Observe the items given in Fig. carefully and answer the questions that follow. 

(a) Food item rich in carbohydrates is __________ .

 (b) Egg is a rich source of protein, the mineral __________ and vitamin __________.

(c) __________ is a rich source of fat.

 (d) Milk provides __________, vitamin D and __________ (mineral)

 (e) __________ (fruit) is a rich source of vitamin A.

 (f) Spinach is a good source of the mineral __________ .

 (g) Both eggs and __________ are rich in __________ .

class 10 Assignment on OUR ENVIRONMENT.

1.What is meant by non-biodegradable waste?  Identify bio-degradable waste from the following:
empty packets of chips,plastic bottle, paper box of sweets,tin of cold drink.

2.Name the group of chemical compound which adversely affects the ozone layer.

3. In which form do the plants store the trapped solar energy?

4. WE do not clean pond or lakes but an aquarium needs to b cleaned. why?

5. Differentiate between food chain and food web.

6. The number of malarial patients in a village increased tremendously when large number of frogs were exported from the village. What could be the cause for this?


7. State any two practices which can help in the protection of our environment.

8.Describe any four modes of disposal of waste.

9. Calculate the amount of energy available to tiger in the following food chain if plants have 30000 J of energy available from the sun.

10. Why are green plants called producers?

11. Draw a line diagram to show the flow of solar energy in ecosystem.

12. LIst any two artificial ecosystems.

13. Why is govt stressing on use of jute or cloth bags?

14. In a colony, it was decided to remove a green park and construct an air conditioned shopping mall. Children of the colony took out a march against this decision with several placards to make the colony people aware of the importance of green plants. 

a. What are the ill effects of air conditioners? 
                              b. Design two placards which the children would have carried? 
c. Is the action taken by the children justified? 
                                   d. How does the ecosystem get affected when plants are removed?

 15 .  In a food chain comprising frogs, insects, birds and grass, which one of the organisms is likely to have maximum concentration of harmful non biodegradable chemicals in its body?

other modes of nutrition in plants

• Most of the plants have green pigment called chlorophyll and can make their own food.
• Some plants do not have chlorophyll and cannot synthesize their own food and are known as Heterotrophic plants
• This type of nutrition can be categorized into
1. parasitic mode of nutrition
2. Insectivorous mode
3. saprophytic mode of nutrition 
4. Symbiotic mode of nutrition

• Let us now explain these modes in detail

Parasites

• In parasitic mode of nutrition, plants depend on other plants or animals for their nourishment.
• Such dependent plants are called as parasites and the ones on which parasites depend are called as hosts. 
• A parasite plant climbs on the host plant from which they get all the food.
• The host does not get any benefit from the parasite.
• Some examples of parasites are Cuscuta (akash-bel), Cassytha (amar-bel), hookworms, tapeworms, leeches, etc.

Insectivorous Plants

• The insectivorous mode of nutrition is observed in plants like pitcher plant and the Venus fly trap.
• These types of plants purely depend on other insects and small animals for their nutrition.
• Pitcher plants trap small insects inside the pitcher and insects are digested by the digestive juices secreted in the pitcher.
• Insectivorous plants grow in those soils which do not contain sufficient nitrogen mineral.
• These types of plants are green and carry out photosynthesis to obtain a part of food.

Saprotrophs

• Mode of nutrition in which organisms or plants that obtain their nutrition from dead and decaying organic matter is called Saprophytic mode

• The plants which exhibit saprotrophic mode of nutrition are called as saprotrophs
• Saprotrophs secrete digestive juices onto dead and decaying matter to dissolve it and then absorb nutrients from it.
• Examples of saprotrophs are moulds, mushrooms, yeasts and some bacteria.

Symbiotic plants

• In this mode of nutrition there is a close association between two different plants of different categories.
• In such type of association both the plants get benefited.
• For example certain fungi live in the roots of the trees. In this case tree provides nutrients to fungi and in return receives help from it to take up water and nutrients from the soil.

How nutrients are replenished in the soil

• We know that plants continuously take nutrients from the soil in order to synthesize food. As a result of this amount of nutrients in the soil decreases.
• Nutrients in the soil are replenished by adding fertilisers and manures.
• Fertilisers and manures contain plants nutrients and minerals like nitrogen, phosphorus and potassium.
• Another way to replenish soil is to grow leguminous crops (for example gram, peas, pulses etc.) in the soil.
• The bacterium called Rhizobium can take atmospheric nitrogen and convert it into a soluble form.
• But Rhizobium cannot make its own food. So it lives in the roots of gram, peas, moong, beans and other legumes and provides them with nitrogen. In return plants provide food and shelter to the bacteria.
• Thus plants and bacteria have a symbiotic relationship here.

CLASS 7 ASSIGNMENT  NUTRITION IN PLANTS.
TAKE A PRINT OUT ATTACH A RULED PAPER AND SOLVE THE ASSIGNMENT.

Fill in the blanks:

1. The components of food which are necessary for our body are called _______________

2. Green plants synthesise their own food themselves by the process of __________________.

3. ______________________ is the mode of taking food by an organism and its utilization by the body.

4. Complex chemical substances such as ______________ are the products of photosynthesis.

5. ___________________ gas is produced during photosynthesis.

6. Organisms that are dependent on others for their nutrition are called ______________________

7. _________________ are the tiny pores present on the surface of the leaves and are surrounded by guard cells.

8. ____________________is the ultimate source of energy for all living organisms.

9. Organisms which derive their nutrition from dead decaying matter are called _______________.

10. Some organisms live together and share shelter and nutrients, this is called _____________________.

11. Carbohydrates are made up of _________,__________ and __________.

Name the following :

1. A bacterium that can take atmospheric nitrogen and convert it into a soluble form.

2. An insectivorous plant.

3. The mode of nutrition in mushrooms.

4. The indicator used to test the presence of starch in leaves.

CLASS 6 ASSIGNMENT ON COMPONENTS OF FOOD.
TAKE A PRINT OUT ATTACH RULED PAPER AND SOLVE THE ASSIGNMENT.

Question 1

State True or False

(a) Deficiency of Iron causes  Anaemia.

(b) Vitamin D helps in clotting of blood.

(c) Deficiency of Vitamin C Causes Scurvy.

(d) Carbohydrates and fats mainly provide energy to our body.

(e) Some nutrients get lost in the process of cooking. 

(f) Dietary fibers are also known as roughage.

Question 2

Fill in the Blank

1. Sea Food is a rich source of ______

2. _______________helps in protecting our body against diseases.

3. A solution of _________ and Caustic Soda is used to detect the presence of proteins.
 

4. Food containing ______________ are often called the body building foods

5. vitamin ….   keeps our skin healthy

6. ___________ is essential for forming hemoglobin in the blood.

7. Wounds take longer time to heal when we have deficiency of ……….

8.  ……. for the body should contain a variety of food items

Question 3:

Match the column

Column A	Column B
Carbohydrates and fats	Protective food
Proteins	Causes loss of Vision
Vitamins and Mineral	energy-giving food.
Dietary fibers	Causes the disease called goitre.
Iodine deficiency	They help us in easy digestion of food.
Lack of vitamin A	Body-building food

Question 3.

Name the following

1. They are oxidized in the body into simple sugars like glucose.

2. They are also known as Dietary fibers.

3. They are chemical substances that help in maintaining a healthy body.

4. Proper functioning of thyroid gland.

5. It protects us from dehydration.

6. They act as building blocks and serve as materials helping in growth and repair of the body cells and tissues.

7. It is required to carry nerve impulses in the body

8. it is required for Formation of haemoglobin in red blood cells.

CLASS CELL: THE FUNDAMENTAL UNIT OF LIFE. NOTES.

Cell is called the fundamental unit of life. A cell is capable of independent existence and can carry out all the functions which are necessary for a living being. A cell carries out nutrition, respiration, excretion, transportation and reproduction; the way an individual organism does. Unicellular organisms are capable of independent existence which shows a cell’s capability to exist independently. Due to this, a cell is called the fundamental and structural unit of life.

All living beings are composed of the basic unit of life, i.e. cell.

 CELL THEORY (Schleiden, Schwann and Virchow):   • All living organisms are composed of one or more cells. •

 The cell is the basic unit of structure, function, and organization in all organisms. •

 All cells come from preexisting, living cells.

 STRUCTURE OF CELL   Shape and Size of Cells:- Cells come in all shapes and sizes. While most of the cells are spherical in shape, cells of various other shapes are also found. Most of the cells are microscopic in size, i.e. it is impossible to see them with naked eyes. Some cells are fairly large, e.g. a neuron in human body can be as long as 1 meter. The egg of an ostrich is the largest known cell of a living animal and an average egg is 15 cm long and 13 cm wide

. A cell is enclosed in a membranous casing and is filled with a liquid substance which is called the cytoplasm. There are many cell organelles in a typical cell. Some of the main structures of a cell are as follows:

 Cell wall: Cell wall is made of cellulose. It is somewhat hard but permeable to most of the substances. Cell wall is available in plant cells and in cells of bacteria and fungi.

 Plasma membrane: Plasma membrane is a semi-permeable membrane. It is composed of bilayer of lipid and protein.

 Functions of Plasma Membrane: Plasma membrane provides a container to the cytoplasm. It facilitates passage of various substances in and out of the cell.

 Nucleus: Nucleus is covered by double membrane; called nuclear membrane. The fluid which is inside the nucleus is called nucleoplasm. Nucleus contains chromosomes which are important for the functioning of a cell. Chromosomes contain genes which are the carriers of genetic information. Nucleus plays an important role during cell division. Nucleus controls all the functions of the cell.

 Prokaryotes and Eukaryotes:- Based on the level of organization of nuclear material, a cell can be categorized as prokaryote or eukaryote. In some organisms, the true nucleus is absent. This means that the DNA and RNA are not bound by a membrane. Bacteria and blue green algae are examples of prokaryotes.

 When genetic materials are bound by a membrane, it is termed as true nucleus. In this case, the cell is called eukaryotic.

 Organisms other than bacteria are eukaryotes. Eukaryotes are considered as more advanced than prokaryotes.

Examples: Algae,Fungi,Plants and Animals cells.

Mitochondria: Mitochondrion is a capsule-like structure. It is a double membrane structure. Its inner membrane is projected into numerous finger-like structures; called cristae. Mitochondria are the sites of cellular respiration. After cellular respiration, energy is stored in the form of ATP (Adenosine triphosphate); in mitochondria. Mitochondria have their own DNA and ribosomes and hence mitochondria can produce their own protein. Functions of Mitochondria:- Cellular respiration; due to this, mitochondria are also known as the ‘powerhouse of the cell’.

  Endoplasmic Reticulum: Endoplasmic reticulum is a mesh-like structure which is composed of numerous tubes. It extends from the plasma membrane to the nuclear membrane.

There are two kinds of endoplasmic reticulum, viz. smooth ER and rough ER. Rough ER has ribosomes on its surface which give it the rough appearance.

Function of ER: It serves as the transport channel in the cell. Substances are transported from cell membrane to cytoplasm and to nucleus and vice-versa. ER also serves the role of packaging many substances in the cell.

 Golgi Complex: Golgi Complex was discovered by Camillo Golgi. It is composed of many sac-like structures which are stacked one above another. Functions of Golgi Complex: Golgi complex is responsible for packaging of various substances in the cell.

 Lysosome: Lysosome are small sac-like structures and they are derived from Golgi complex. Lysosome contains digestive enzymes.

 Functions of lysosome: The enzymes in the lysosome digest foreign particles and thus destroy them. Sometimes, the lysosome may burst open and its content ends up digesting the contents of the cell. The cell gets killed in the process. Due to this, lysosome is also called the ‘suicide bag of the cell’.

 Ribosome: These are tiny dot like structures interspersed in the cytoplasm and also on the surface of Rough ER. Ribosome is responsible for protein synthesis. Plastids: These are somewhat similar to mitochondria; in appearance.

Plastids are found in plant cells. They are of two types, chromoplast and leucoplast. Colourful plastids are called chromomplast and colourless plastids are called leucoplast. Chloroplast is green in colour and is found in green parts of plants. Plastids too have their own DNA and ribosome.

 Functions of Plastids: Leucoplasts are responsible for storing food; such as carbohydrates, protein and lipid.

 Chromoplasts impart various colours to the plant parts. A leaf of a plant is green in colour because of chloroplast. Chloroplast is the site of photosynthesis.

 Vacuoles: These are fluid filled chambers and are often seen in many cells. Vacuoles are very large in plant cells. A plant cell usually has single but large vacuole. Such a vacuole fills almost the entire space inside the cell. Vacuoles are much smaller and very few in animal cells.

 HISTORY OF DISCOVERY OF CELLS

  • Robert Hooke was the first to discover cell (1665)

. • Leeuwenhoek was the first to discover free living cells in pond water (1674)

. • Robert Brown discovered the nucleus (1831).

 • Purkinje coined the term ‘protoplasm (1839).

 • Schleiden (1838) and Schwann (1839) proposed the Cell Theory. Virchow (1855) made further addition to the cell theory

. • The discovery of electron microscope (1940) made it possible to study the structures of cell organelles.

                                                                     class -7




                                 https://www.youtube.com/watch?v=lji6Zx3_E30
                                                           




                                https://www.youtube.com/watch?v=0gGl-h4CIW0                                         
                                                       

class-8

class 6

components of food

class 7

class 7

photosynthesis in plants.