VIIth Std Science I sem
Index
Page No
Sl no
Lessons
1.
2
2.
Organization
in
the
living
organisms
Nature and composition of matter
3.
Life process
6
4
Water
12
5
Heat
15
1
5
1.Organization in the living organisms
I Fill in the blanks .
1. The fluid present between the cell membrane and the nucleus is
called cytoplasm.
2. The part which controls all the activities of a cells called Nucleus.
II Name the following.
1. Power house of a cell – Mitchondria
2. Protein factories of a cell Ribosome.
III Give one example for the following.
1. Supporting tissue -coconut fiber
2. Organ of the body which has the involuntary muscles
vessels.
-blood
IV write functions.
1. Golgi complex: It helps in the secretion of chemicals.
2. Centro some : It helps to produce spindle fiber during cell division .
3. Motor Nerve cell: Helps to transmit command message from the
brain to various parts of the body.
V. Choose the correct answer and fill in the blanks:
1. The structural and functional unit of living organisms is cell
a) Cell
c) Organ
b) Torque
d) Organ system
2. The organelle which is known as suicide bag of the all is
Lysosome
a) Mitochondria
c) Lysosome
b) Ribosome d) Golgi complex.
VI. Ans the following:
1. What is cell ?
Ans : The Structural and functional unit of living organisms is known as
cell.
2. What is unicellular organisms ? Give ex .
Ans : The microscopic organisms having single cell are called
unicellular organisms
Example : Amoeba , Euglena,
3. What is a tissue?
2
Ans : Group of cells similar in structures and perform a definite
function are called Tissue.
4. What is multi cellular organisms ?
Ans : The organisms having more than one cell are called multi
cellular organism.
Example :- mango , Dog, man.
5. What is axon ?
Ans : The long protoplasmic projection of nerve cell is called
axon.
6. What are conducting tissue?
Ans:
The special tissues in plant which conduct water ,minerals , salts
and food are called conducting tissues or vascular tissues.
VII Give scientific reason.
1. Amoeba is called an unicellular organism ?
Ans. Amoeba is called an unicellular organism because it contains a single
cell.
2. Mitochondria are the sites of respiration of the cell.
Ans: During respiration the food is oxidised and energy is released so
mitochondria are called the
power house the cell.
3. Xylem and phloem are called vascular tissue.
Ans. Xylem and phloem are called special tissue in plants for
conducting water, minerals, salts and food
VII Answer the following.
1. what are animal and plant tissue? Name any four plant tissue.
Ans. Group of cells similar in structure and performs a definite function
are called tissue. Epithelial tissue, nervous tissue. Animal tissues.
Epidermal tissue and meristematic tissue are plant tissue.
2. Explain the structure of nerve cell with the help of a diagram.
Ans.
3
Structure: The neuron has a cell body with a nucleus. From the
cell body one or more protoplasmic projections arise these projections are
called Dendron or dendrites’. One of these projections is long and is
known as Axon .
IX write the difference
1. Xylem and phloem :
Xylem
: These conduct water , minerals and nutrients from roots to
leaves.
Phloem
:These tissues transport food materials from leaves to
different parts of plant.
2. Voluntary and involuntary muscles.
Ans. Voluntary
: Voluntary muscles are controlled try the will power of
animal.
Involuntary : These muscles are not under the control of animal.
X Draw diagrams and label the given parts.
1. Animal cell
a.cell wall
c. nucleous
b. mitochondria
d. Golgi complex
4
2.
a.
b.
c.
Amoeba
Nucleous
Food vacuole
Cell wall
5
2.Nature and composition
I Fill in the blanks.
1. In starts the matter is in plasma state .
2. The system of denoting the elements by system is given by Berzilius
3. The elements present in glucose are carbon ,hydrogen and oxygen.
II Mention the following .
1. Method of separating the mixture of alcohol and water.
Ans. Fractional distillation.
2. Representation of molecule with the help of system of atoms
present.
Ans. Molecular formula
III Give two examples:
1. Liquids
- Bromine, mercury.
2. Solid
-Iron ,Gold
3. Elements -Mercury ,silver, helium
4. Compounds -water (H2o ), Carbon-di-oxide
acid(H2SO4)
(co2),Sulphuric
IV write the molecules formulas:
1. Sulphuric acid – H2SO4
2. Ammonia NH3
3. Carbon di oxide - CO2
4. Sodium hydroxideNaoH
V The symbols of some elements are given below ,writes this name.
1. O –oxygen
2. N-nitrogen
3. Mg- Magnesium
4. co - cobalt
VI Chose and write the most appropriate one and write the correct
answer in the space provided.
1. Non mental among the following is carbon
a) Carbon
c) Gold
b) Silver
d) Sodium
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2. Molecular formula of Ammonia is NH3
a) NH3
c)HNO3
b) Nacl
d) KMNO4
3. The ratio of hydrogen and oxygen present in the water molecule 2:1
a) 2:1
b)3:1
c) 1:1
d) 1:2
VI Answer the following .
1. What is mixture?
Ans. A mixture consists of two or more substances mixed physically in
any proportion.
2. What is compand?
Ans. Two or more elements chemically combine in definite ratio to form
a compound.
3. What is suspension?
Ans.
In the mixture of clay and water the clay particle .settle at the
bottom This is called suspension.
VIII Give scientific reason.
1. Liquid flow:
The molecules in liquids are not close together . the attraction
between the molecules is less. The molecules in liquids can slide on each
other. Because of this property liquids flow easily.
2. Gasses have no definite shape and volume.?
Ans.
In gasses intermolecular space is more, molecules move
independently in all direction gasses take the shape and volume of the
container. So gases have no definite shape and volume.
IX write the difference.
1. Solution and suspension .
 Solution : homogeneous mixture particles cannot be seen.
 Suspension : In this mixture particles of clay settle at bottom.
2. Atom and Molecule
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 Atom : Atom is the smallest particle of an element which has all the
properties of that element.
 Molecule : Minute particle of an element or compound having stable
existence is called molecule.
3. Element and compounds
 Element : Element are the substances that contain only one kind of
matter
 Compound : Two or more element combined chemically in definite
ratio to form compound.
X Answer the following
1.
What are the properties of matter ?
Ans. The properties of matter are :
1. Matter occupies space
2. Matter has mass.
2.
Explain the arrangement of molecules & gasses.
Ans. Liquids : The molecules in liquids are close together means loosely
held. The attraction between the two molecules is less . The molecules can
slide over each other . Because of this property liquids flow easily : Gases
In gasses the molecules move independently in all direction the inter
molecules space is more so gasses and be compressed.
Elements
Symbol
1. Gold
Au
2. Silver
Ag
3. Mercury
Hg
4. Potassium
K
5. Iron
Fe
6. Copper
Cu
7. sodium
Na
8. Lead
Pb
9. Tin
Sn
10.Calcium
Ca
8
Compound
Hydrochloric
acid
Calcium
carbonate
Potassium
permagande
Glucose
Sodium
chloride
Molecular
Formula
HCl
Ca Co3
KMno4
C6H12O6
Nacl
9
3.Life process – ( Part I)
I
Fill in the blanks .
1. The interaction between autotroph’s and heterotrops is called food
chain.
2. Insectivorous plants cannot manufacture nitrogenous compound .
3. Hydra catches food with the help of tentacles.
4. Blood is a liquid tissue.
5. Red blood cell have a red pigment called haemoglobin.
II
Name the following.
1. The process which converts the chemical energy into heat energy Respiration.
2. Obtaining ,digesting and assimilating the food
- Nutrition in
Amoeba.
3. The process which is found only in green plants -photosynthesis.
4. Respiratory organ is frog –Its moist skin and lungs.
III
Give one example for:
1. Parasites
2. Insectivorous plants
IV
- ex : Hook worm.
- ex : Venus – fly –trap.
Give one use for
1. Sphygmomanometer
2. Stethoscope
V
: used to measure blood pressure.
: used to measure the heart beats.
Match the following:
1. Photosynthesis
2. Respiration
3. Digestion
4. Nutrition
- Manufacture of food.
- Oxidation of food.
- Breaking up of food.
-Digestion
and assimilating the
food
-Throwing out of waste
5. Excertion
VI
choose and write the correct answer.
1.
The constituents of the blood, which destroys the disease causing
germs white blood cell.
a) White blood cell
c) plasma
b) Red blood cell
d) platelets.
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2.
3.
VII
The organisms which depends upon the herbivorous for food
among the following is , tiger.
a) Goat
c) deer
b) Cow
d) tiger
Photosynthesis takes place in this part of the plant : Leaf
a) Leaf
c) root
b) Flower
d)nut.
Answer the following :
1. Name the process by which green plants manufacture the food.
Ans.
The process by which green plants manufacture the food is
photosynthesis.
2. What are saprophytes?
Ans. Agaricus (mushroom) and certain bacteria obtain their food from
decaying organic materials. They are called saprophytes.
3. Which is the process that helps in the exchange of gasses in an
earthworm?
Ans. Diffusion is the process that helps in the exchange of gasses in an
earthworm.
4. Name the constituents of blood?
Ans. The constituents of blood are plasma, white blood cells, red blood
cell and platelets.
5. what is blood circulation.
The flow of blood from heart through blood vessels to parts of the
body and back to heart is called blood circulation
II
Give scientific reason.
1. The leaves of plants are green colour.
Ans. The leaves of plants are green in colour because due to the presence
of pigment called chlorophyll in cells.
2. Hookworm is called a parasite.
Ans.
Hookworm obtain its food from other living organism such
organism are called parasite.
3. Doctor tests the blood of the patient and the doner before blood
transaction.
Ans The proteins present in one blood group match with specific
proteins in a perticular blood group. So doctors test the blood before
tranfusion
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IX
write the difference between
1. Inspiration and expiration .
 Inspiration : taking air through the nose into the lungs is called
inspiration .
 Expiration : giving out air from lungs into the atmosphere is
called expiration.
2. Arteries and veins.
 Arteries : Arteries carry the blood to all parts of the body start
from ventricle
 Veins : Veins bring the blood from all the parts of the body to
auricle.
3. Pulmonary circulation and systemic circulation
 Pulmonary circulation : The flow of deoxygenated blood from
the heart to the lungs giving up carbon di oxide ,absorbing
oxygen and returning to the heart as oxygenated blood is called
pulmonary circulation.
 Systemic circulation
: The flow of oxygenated blood
from the heart to the cells of the body providing oxygen ,
absorbing carbon dioxide and returning to the heart is called
systemic circulation.
4. Autotrophs and hetrotrophs.
 Autotrophs
: Autotrophs prepare their own food eg: Green
plants.
 Heterotrophs : heterotrophs depends on autotrophs e g: Deer,
cow.
5. Aerobic respiration and Anaerobic respiration.
 Aerobic respiration : organism make use of oxygen to oxide food ,such a
respiration is called aerobic respiration.
 Anaerobic respiration : organism like feast , bacteria , break the food to
obtain energy without the help of oxygen. Such a respiration is called
Anaerobic respiration..
X
Answer the following :
1. What is blood transfusion ?Name the different groups of blood .
12
Ans. Blood being given to patients after an accident or an operation .
this is called blood transfusion . Blood is grouped into four types namely
A,B,AB ,and O.
2. Explain the process of photosynthesis?
Ans. Green plants in the presence of sun light water and carbon –di oxide
prepare starch and release oxygen to the environment this process is
called ‘photosynthesis’.
Carbon di oxide + water
sunlight + glucose + oxygen
Cholorophyll
3. Give two importance of photosynthesis.
Ans. The two importance of photosynthesis are:
1. Green plants manufacture food. Non–Green plants and animals
directly or indirectly depend upon green plants for their food.
2. Oxygen which is necessary for respiration is released during
photosynthesis. There by the oxygen content in atmosphere is
maintained.
XI Draw diagram of the following and label the given part.
1.
1.
2.
3.
4.
5.
6.
Digestive system.
Oisophogus
Stomach
Intestine
Pancreas
Liver
13
2. Heart
1. Aorta
2. Pulmonary veins
3. Left auricle
4. Right ventricle
3.Respiration organ.
1. Nose
2. Windpipe (trachea)
3. Lungs
4. Voice box
14
Water H2O
I
Fill in the blanks
1. A molecule of water is made up of two atoms of hydrogen and one
atom of oxygen.
2. The device used to find the constituents of water is voltameter
II
Name the following.
1
The solvent which dissolves most of the substances.
Ans. water
2.
The solvent which contains maximum salute.
Ans. Saturated solution
III
Give example :
1. Natural purifier of water –fish , tortoise
2. Gasses that dissolve in water – Hydrogen, Nitrogen, oxygen
IV What happen:
1. A piece of sodium is dropped on water.
Ans. Sodium reacts with water and hydrogen will liberate.
2. An iron road is left in moist air.
Ans. Iron will react with moist air, ferric oxide will form
V choose and write the current answer:
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1. Water is a compound.
a) An element
b) A compound
c) a mixture
d) suspension
2. Due to the content of mercury in water the diseases caused is
minamata.
a) Anemia
c) Heart problem
b) Disease of kidney
d) Minamata.
VI Give reasons:
1. Sodium is preserved in kerosene.
Ans. Sodium is highly reactive metal .It reacts with water vapour present
in air , so it is preserved in kerosene.
2. Salt water is not useful for industrial purposes. ?
Ans. Salt water will damage the vessels in the industry, So salt water is
not useful for industrial purpose.
I Answer the following .
1. Why is water called universal solvent.
Ans. Water is a universal solvent because many substance dissolve in
water.
2. What is saturated solution?
Ans.
The solvent which contains maximum solute is called saturated
solution.
3. What is water pollution ?
Ans. Water which is not fit for drinking and not fit for aquatic animal to
live in. The physical,chemical and biological characteristics of water
are changed by the addition of waste materials by various activities
of man is called water pollution.
Difference between .
1. Distilled water and drinking water.
 Distilled water: Distilled water is free from salts.
 Drinking water: Drinking water contain salts and minerals.
2. Saturated solution and unsaturated solution
 Saturated solution :Saturated solution contain maximum quantity of
solute.
 Unsaturated solution : Saturated solution can be made unsaturated
by adding water.
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IX Answer the following :
1. Explain the method of preparation of saturated salt solution.
Experiment:
Take a small quantity of water of known temperature in a
beaker .Add a small quantity of small quantity of salt to it, stir it till
the salt dissolves in water . add some more salt and stir it well .
continue adding salt and stirring till , no more salt dissolves in it
and some salt settles down . This is a saturated solution of salt.
Maximum amount of salt has dissolved in that solution.
2. Explain the method of obtaining distillated water.
Ans. Distillated water .
Refer page no 53 distillation figure
17
Take salt water in a retort. Set the apparatus as shown in the
diagram heat the water till it evaporates and collect the water vapour in the
receiver and cool it. Water vapour condenses to form distilled water, salts
and minerals which do not vapourise remain in the flask. Distilled water is
free from dissolved salts.
3. Give an experiment to show that water is the bad conductor of heat.
Ans. Experiment.
Refer page no 48, test tube holding figure
Take a few pieces of ice in a test tube . place a piece of wire guage
over the ice to prevent it from floating. Fill ¾ of the test tube with
water . heat the water at the top.The water at the top Starts to boil in a
few minutes , but the ice at the bottom remains as it is . even though
the water at the top is boiling the heat does not get transferred to the
ice . this shows that water is bad conductor of heat.
4. List the method of controlling water pollution?
Ans. Method of preventing water pollution s:
1. Disposal of human and animal excreta into water should be avoided
.
2. Industrial waste must be chemically treated to remove harmful
substances before they are released into water.
3. Toilets should be built in every home.
4. Animals excreta should be converted into manure by burying them
in pits.
5. Sewage water must be treated before it is released into rivers .
6. Dumping of dead bodies & carcasses into river should be avoided.
7. Aquatic animals like tortoise and special types of fishes help in
purifying the water. They are termed as natural purifier of water.
18
Heat
I Fill in the blanks .
1. The unit of heat is calorie or Joules.
2. Heat is a form of energy
3. Latent heat of fusion of ice of 1 gram is 80 calories.
II Name the following .
1. The device used to measure the temperature of substance laboratory thermometer.
2. The heat required to convert the given liquid completely into its
gasses form at its boiling point –Latent heat of vapourisation .
III Give examples.
1. Conductors of heat
->Aluminum , copper.
2. Insulators of heat .
->Brick, stone , asbestos.
3. Fuels.
-> Kerosene , petrol.
IV choose and write the correct answer:
1. The substance which has the least capacity kerosene.
a) Mercury
c) Alcohol
b) Water
d)kerosene
2. The liquid used in thermometer Alcohol or mercury .
a) Mercury or water
c) Alcohol
b) water or alcohol
d) Mercury or kerosene
V Write the functions:
1. The plastic handles in the heating vessels
Ans. Plastic are the bad conductors of heat. Helps to handle hot vessels
2. Mercury in thermometer?
Ans. Mercury in thermometer helps to measure the temperature.
VI Answer the following
1. Define calorie.
19
Ans.
The heat required to raise the temperature of 1 gram of water
through 10 Celsius is called calorie.
2. What is the relationship between calories and joule ?
Ans. The relationship between calories and joule is 1 calorie =4.2 joule.
3. What is radiation of heat?
Ans.
Transference of heat takes place from hot body to cold body this
process is known as radiation.
VII Give scientific reasons.
1. Electric wire sag in summer?
Ans. Electric wire sag in summer because of heat, the length of electric
wire
increase.
2. Cooking vessels are made of metals?
Ans. Cooking vessels are made out of metals because the heat capacities
of metals are less.
3. By using pressure cookers, cooking becomes faster.
Ans. In the pressure cooker the steam remains inside cooker developing
more heat, hence food is cooked fast.
VIII Difference between.
1. Conduction and convection of heat.
Ans. Conduction : Transfer of heat takes place due to the vibration of
the particles .Conduction takes place only in solid.
Convection: Heat is transmitted by the actual movement of the
particles. Convection takes place only in liquids and gasses.
2. Heat and temperature:
Ans. Heat : Heat is the feeling of hotness and establishes its existence
Temperature : The degree of hotness of a body is temperature.
20
IX Answer the following :
1. How do we find the boiling point of water experimentally.
Ans.
Take some water in a flat bottom flask fitted with two holed rubber
cork . through one hole pass a bent glass tube and through the other a
thermometer . when water is heated there is rise in temperature. At certain
stage water starts boiling . the temperature at which the water boils is
called boiling point of water . even if you continue the supply of heat to
water there will be no rise in temperature . Note this temperature that is
1000 c . the boiling point of water is 1000 c.
21