Unit - 1
SCIENCE IN EVERYDAY LIFE
Role of Science in Everyday Life
1.1 Man – Science
Key points :
Science changed early man into a civilized man.
Early man observed and understood nature and surroundings. he learnt to produce fire.
Early man observed germinating seeds and developed agriculture. He invented tools to make his work easy.
Scientists observe everything critically and make verifications.
artificial fibres (threads) are synthesized using chemicals.
Science helped in the construction of huge buildings.
Development of science provided protection from dreadful diseases.
The needs of growing population are met with the development of Industry.
Increased food production was achieved through green revolution.
Science solves the problems of mankind. But its misuse results in the destruction of mankind.
III Additional Activities :
1.Discuss the relationship between human life and science.
2.Refer various magazines and collect information from various magazines about how science helped in the human development and display in your classroom.
3. Do (Take up) a project in your locality about an issue/ incident in which science is used for development
Evaluation
Unit - I
Role of Science in Everyday Life
I Answer the following questions :
1. What is science?
Ans: Science is a quest for truth. Science isa systematized body of knowledge and a way of life.
2. How has science helped in higher food production ?
Ans: Higher food production became inevitable to meet the needs of growing population. Through research new, better varieties of rice, wheat, jowar etc., which are disease resistant and give high yield were produced. This led to Green Revolution
3. How did early man learn to cultivate crops ?
Ans: Early man while wandering observed seedlings, flowers, fruits and seeds. All these were part of his food. After observing the germinating seeds, he learnt to sow seeds and raise crops. He invented tools to make his work easy.
4. What are the various industries established to meet the needs of growing population ?
Ans: Various industries were established to meet the needs of growing population. Some of them are - Fertilizer factories, Power Generating Centres, Oil Refining factories, Iron and Steel factories, Pharmaceuticals, Coal industries, Automobile manufacturing industries etc.
- What are the harmful consequences of human actions ?
Ans: The use of nuclear weapon produces radioactive dust which is harmful to human beings, plants and animals. Man is responsible for the environmental pollution caused due to use of pesticides, artificial fertilizers, smoke emitted from vehicles and industrialization. As a result, man is causing harm to other living forms.
II Fill in the blanks :
1.The branch of science which deals with the production of artificial fibres is Polimer chemistry
2.To eradicate superstitions scientific knowledge is essential.
Unit - 2
LIVING WORLD
2.1 Living Organisms – Characteristics
Important points :
Growth, locomotion, nutrition, respiration, reproduction etc. are the characteristics of living organisms.
The permanent change in the size of an organism is known as Growth.
Growth in animals stop after sometime. But growth in plants is throughout their life.
Animals move. Plants are fixed.
Plants prepare their own food materials in the chloroplasts with the help of water, corbondioxide and sun light.
Respiration helps to release the energy present in the food.
The process of excreting the waste materials formed in an organism during metabolism is called Excretion.
Responding to various stimuli is a characteristic of living organisms.
Living organisms give rise to their off springs to perpetuate their race.
Evaluation
I Answer the following questions in 1-2 sentences:
1.What are living organisms? Give two examples.
Ans: The things which have life are called living thingsor living organisms. Ex. Cows, buffaloes, cats, rats.
2.What is meant by growth?
Ans: Permanent change in the size of living organisms is known as Growth.
3.Which process helps organisms to continue their race?
Ans: Reproduction is the process which helps organisms to continue their race.
- Give two examples to show that plants respond to external stimuli.
Ans: When a “touch-me-not” plant is touched, it immediately folds (and droops) its leaves. After some time, the leaves get back to their original state. The shoots of plants grow towards light above the ground. Roots grow deep into the soil. Lotus blooming during day, water lily blooming in the night, sun- flower facing sun, etc. are the responses that plants show to external stimuli.
II Answer the following questions in 5-6 sentences :
1.Describe the characteristics of living organisms.
Ans: Growth, locomotion, nutrition, respiration, reproduction etc. are the characteristics of living organisms.
1. Growth: The permanent change in the size of an organism is known as Growth. Growth in animals stops after sometime. But growth in plants is throughout their life.
2. Locomotion: Animals move from one place to another for food, to protect themselvesfrom the attack of other animals and for shelter.Animals possess different organs for locomotion. These are called locomotory organs.
Plants do not move. They remain where they are throughout their life. they are fixed firmly into the soil.
3. Nutrition: Energy is needed for growth, movement and responses of the living organisms. Organisms get energy from the food they take. The energy giving food materials are called nutrients. The complete food which provides all nutrients is called nutritious food.
4. Respiration :Energy is released only when this digested food reacts with oxygen. For this, living organisms take in oxygen from atmosphere through various respiratory organs.
5. Reproduction : All organisms grow, become adults, live for some time (certain period) and then die. But still the living forms do not become extinct. This is because they reproduce to give rise to their off springs.
- Compare the characteristics of plants and animals.
Character / Plants / Animals
food / They prepare their food on their own / These will depend on other organisms
locomotion / They can not move / They have different locomotory organs to move
Inner metabolism / They don’t have blood. They have chloroplast. / Most of the animals have blood circulation system.
respiration / They take carbon dioxide / They take Oxygen
growth / Grow through out their life / Growth will stop after some time.
reproduction / They produce their offspring by means of seeds or through their body parts. They produce many a number of young plants during their life time. / They produce offsprings either by laying eggs or giving birth to young ones. Generally they give birth to a small number of young one in their life time.
dependency / Newly born plant will not depend on its mother plant or tree. / Generally mother animal help the young ones for some days.
III Fill in the blanks with suitable words :
1.The permanent change in the size of organism is called growth .
2.Gills are the respiratory organs in fish .
3.Lungs are the respiratory organs in animals ( Man).
4.Living forms can exist continuously through reproduction .
IV Choose the correct answer :
1.One of the following is not a characteristic of plants( b )
(a) Growth (b)Locomotion (c) Reproduction (d) Responding to external stimuli.
2.The organisms which are capable of using the waste material formed as a result of metabolism are ( a )
(a) Plants (b) Animals (c) Humans (d) Parasites
Let us think :
1.Imagine the locomotory organs in various animals.
2.Why birds can fly in sky, why not humans ?
2.2 Classification of living organisms-Plants and animals
Important points :
The systematic arrangement of living organisms on the basis of their similarities and differences is called Classification.
On the basis of flowers, plants are classified as non flowering plants (cryptogams ) and flowering plants(phanerogams).
Non flowering plants (cryptogams ) are divided into Thallophyta, Bryophyta and Pteridophyta.
In gymnosperms, seeds are not enclosed in the fruit. They are exposed or naked (visible externally)
In angiosperms, the seeds are either monocotyledonous or dicotyledonous.
Based on their size, plants are classified as herbs, shrubs and trees.
Based on their life span, plants are classified as annuals, biennials, perennials.
Based on the presence of notochord, animals are classified as invertebrates (Non chordates) and Vertebrates (Chordates)
Non chordates are divided into 9 phyla; Chordates are divided into 5 phyla.
Largest number of animals belong to the phylum arthropoda.
Evaluation
I Answer the following questions in 1,2 sentences :
1.What is meant by classification ?
Ans:The systematic arrangement of living organisms on the basis of their similarities and differences is called Classification.
2.Based on flowers, into how many types plants are classified? What are they ?
Ans: On the basis of flowers, plants are classified as non flowering plants
(cryptogams ) and flowering plants(phanerogams).
Non flowering plants (cryptogams ) are divided into Thallophyta, Bryophyta and Pteridophyta.
The plants that flower and bear fruits are called Flowering Plants or Phanerogams. They can be divided into two groups. They are 1. Gymnosperms and 2. Angiosperms
In gymnosperms, seeds are not enclosed in the fruit. They are exposed or naked (visible externally)
In angiosperms, the seeds are either monocotyledonous or dicotyledonous.
3.Into how many classes non flowering plants are divided? What are they ?
Ans: Non flowering plants (cryptogams ) are divided into three types. They are Thallophyta, Bryophyta and Pteridophyta.
4.What are herbs ? Give two examples.
Ans:Herbs are small plants with tender stem. Theygrow upto a height of 3-4 meters. They are upright, without any branches or with fewer branches.
Eg. : Paddy, wheat, mustard, brinjal, lady’s finger.
5.Which part of the animal is the basis for main classification of animals ?
Ans:Based on the presence of notochord, animals are classified as Chordates and Non- Chordates. In Chordates, there is a rod like cartilaginous structure known as notochord.
6.What are annuals ? Give two examples.
Ans:1. Annual plants :- The plants which germinate, flower, give fruits and seeds and complete their life cycle within a year are called annual plants.
E.g : Paddy, wheat , beans, pumpkin, lady’s finger.
7.Write about phylum coelenterata. Give examples.
Ans:Coelenterata – These are diploblastic animals finger like structure called tentacles are present around the mouth. Ex: Hydra.
- What do you call the vertebrates which can live on land and in water? Give examples.
Ans:Amphibia They can live both in water and on land. The skin is moist without any scales. They have two pairs of limbs. The heart is three chambered. They are cold blooded animals. Eg. : Frog, Salamander.
II Answer the following in 5,6 sentences :
1.Explain the importance of classification.
Ans:For studying various living organisms, they are arranged in a systematic manner. Categorizing the living organisms based on their similarities and differences and arranging them in a systematic manner is known as Classification. The study of classification is known as Taxonomy.
Taxonomy is useful to study the living things easily, in a simple manner; to identify a living organism easily; to know the relationships and differences between different organisms; to understand the evolution of living organisms.
Aristotle (384-322 B.C) was the first scientist who made an attempt to classify organisms in a scientific manner.
2.Based on the size of plants, into how many types they are classified ? What are they ? Explain them.
Ans:Plants are also classified based on their size. They are 1.Herbs 2. Shrubs 3. Trees.
1. Herbs :- These are small plants with tender stem. They grow upto a height of 3-4 meters. They are upright, without any branches or with fewer branches.
Eg. : Paddy, wheat, mustard, brinjal, lady’s finger.
2. Shrubs :- These are average sized plants with hard stem. They have branches which grow from base of the plant. Eg. :Rose, jasmine, lemon, pomegranate, hibiscus.
3. Trees :- These are tall plants. They have hard, strong stem. Branches arise at the top (upper part) of the plant. Eg. Mango, neem, tamarind
3.Write about invertebrates.
Ans:Invertebrates : Notochord is absent in animals like insects, earthworms and snails. Such animals are known as invertebrates. They are divided into 9 phyla on the basis of their structure. 1.Protozoa 2.Porifera 3.Coelenterata 4.Platyhelminthes 5.Nemathelminthes 6.Annelida 7.Arthropoda
8.Mollusca 9.Echinodermata
4. Write about the animals having vertebral column.
Ans:Higher chordates : The animals with vertebral column are divided into five groups. They are 1.Pisces 2. Amphibia 3. Reptilia 4. Aves 5. Mammalia.
III Fill in the banks :
1.The study of classification is called taxonomy
2.Mould on bread is an example for fungi
3.Plants which complete their life span within one year are called annual plant
4.In vertebrates, rod like structure made of cartilage is called notochord
5.In higher vertebrates, notochord is converted intovertebral column
6.Animals which can change their body temperature in accordance with the surroundings are called Pisces
IV Multiple choice questions :
1. Algae belong to this class ( a )
(a) Thallophyta (b)Bryophyta (c) Pteridophyta (d) None of these
2.Smooth carpet like plants growing on moist wall belong to this class ( b )
(a) Thallophyta (b) Bryophyta (c) Pteridophyta (d) None of these
3.One of the following is an example for dicotyledonous plant( d )
(a) Coconut (b) Paddy (c) Jowar (d) Mango
4.An example for annuals( a )
(a) Paddy (b) Carrot (c) Neem (d) Coconut
5.Largest number of animals belong to this phylum( c )
(a) Protozoa (b) Coelenterata (c) Arthropoda (d) Mollusca.
6.Animal with three chambered heart is( d )
(a) Pigeon (b) Cow (c) Fish (d) Lizard.
7.Plants are given more importance in this medicine( a )
(a) Ayurvedic. (b) Allopathy (c) Unani (d) Homeopathy
2.3 Parts of a plant- their functions
Important Points :
The flowering plant has root system and shoot system.
Roots absorb water and minerals from the soil and supply them to leaves through stem.
Stem establishes relationship between roots, branches and leaves.
Leaf base, petiole, lamina etc. are the parts of a leaf.
Leaves prepare food material by the process called photosynthesis.
There are four parts (whorls) in a flower- calyx, corolla, androecium and gynoecium. Flower consists of reproductive parts.
Androecium and gynoecium are the reproductive parts of a flower.
Evaluation
I Answer the following questions in 1,2 sentences :
1.What are fibrous roots ?
Ans: In plants like paddy, grass we find many small roots arising from the point where the stem touches the ground. These roots are called fibrous roots.
2.What is a stem ?
Ans: The part of the plant which grows vertically above the ground is called Stem.
3.How many important parts are there in a leaf? What are they ?
Ans: Parts of a leaf :There are three important parts in a leaf. They are- 1. Leaf base
2.Petiole 3.Lamina or leaf blade.
4.Name the parts of gynoecium.
Ans: It consists of three parts namely ovary, style and stigma.
5.What is the function of petals ?
Ans: It attracts insects and helps in pollination.
6.What is the function of petiole ?
Ans: Functions of Petiole :– The stem like part of the leaf that joins the leaf blade to the stem is known as petiole or leaf stalk. It gives support to the leaf. It helps in the transportation of water from stem to leaf and food materials from leaf to stem.
7.What is the function of stem in desert plants ?
Ans: In desert plants, the stem performs photosynthesis. Eg. Opuntia ,Cactus.
- Why are there aerial roots in banyan tree ?
Ans: In some trees, when branches are widely spread, some roots arise from the branches and give support to the main stem. Eg. Aerial roots of Banyan tree.
II Answer the following questions in 5-6 sentences :
1.Explain the root system with the help of a diagram.
Ans: The part of a plant that lies below the surface of the soil is root.’ It is light in colour, has many branches. In plants like marigold, main root grows vertically downwards into the soil. This is called ‘Tap Root’ or ‘Parent Root’
In plants like paddy, grass we find many small roots arising from the point where the stem touches the ground. These roots are called fibrous roots.
2.Write the functions of stem.
Ans: 1. Gives support to branches, leaves and fruits. 2. Establishes connection between roots and leaves. 3. Supplies water and minerals dissolved in water from roots to leaves, flowers and fruits. 4. Supplies the food material prepared in the leaves to roots and other parts of the plant. 5. In young plants, the stem also performs photosynthesis. 6. In some plants, the stem stores the food material. Eg. Sugarcane, Turmeric, Ginger, Potato, Garlic. 7.In desert plants, the stem performs photosynthesis. Eg. Opuntia ,Cactus. 8.Gives support to climbers.
3.What are the functions of leaf?
Ans: 1. Prepares food material by the process called photosynthesis.2. Regulates the consumption of oxygen and carbon dioxide.3.Regulates the transportation of water and salts by the process called transpiration. 4. Modifies as thorns in desert plants and helps in withstanding water scarcity. Eg. Opuntia. 5. Modifies as coiled structures/ climbers in weak stemmed plants and helps in climbing. Eg. Pea plant. 6. Helps in vegetative reproduction. Eg. Bryophyllum.
4.Write about the male and female reproductive parts of a flower.
Ans: 1. Androecium :– Androecium consists of stamens. Each stamen is made up of a filament and anther. Anther consists of pollen grains. It is the male reproductive organ.