Explain the relationship between sanitation and disease.
A large number of diseases are caused due to poor sanitation and contaminated drinking water. Poor sanitation leads to the growth of harmful microbes, flies and mosquitoes which are the source of spreading many diseases like cholera, typhoid, polio, meningitis, hepatitis and dysentery. So it’s better to have good sanitation and proper hygiene. Sanitation refers to public health conditions related to clean drinking water and adequate treatment and disposal of human wastes and sewage. Preventing human contact with faeces is part of sanitation, as is hand washing with soap.
Relationship between Sanitation and Diseases:
1. In our country, a large number of people even today do not have sewage facilities and thus defecate in open fields, railway, tracks, etc. The untreated human excreta thus pollute soil and water sources including the underground water. When this contaminated water is used for drinking, it can cause diseases such as cholera, typhoid, hepatitis, dysentery, etc. which may even lead to death. Therefore, the lack of sanitation resulting in the drinking of contaminated water can cause health problems.
2. If sanitation is there, no disease will occur; but if sanitation is not there various types of diseases will occur and spread. So sanitation should be kept to avoid diseases.
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
Sketch the cross section of soil and label the various layers.
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human body
Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
Sketch the reproductive parts of a flower.
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.
Describe how crystals of copper sulphate are prepared.
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus
Write one similarity and one difference between the nutrition in amoeba and human beings.
What is meant by the following terms?
(i) Rearing (ii) Shearing (iii) Sericulture
Which of the two changes frequently, weather or climate?
Sketch the reproductive parts of a flower.
What are decomposers? Name any two of them. What do they do in the forest?
Will the compass needle show deflection when the switch in the circuit shown by Fig.14.24 is closed?
When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.
Fill in the blanks:
(i) The average weather taken over a long time is called ___________. (ii) A place receives very little rainfall and the temperature is high throughout the year, the climate of that place will be ___________ and ___________ .
(iii) The two regions of the earth with extreme climatic conditions are ___________ and __________.
Fill in the blanks.
(i) The blood from the heart is transported to all parts of the body by the.
(ii) Haemoglobin is present in cells.
(iii) Arteries and veins are joined by a network of .
(iv) The rhythmic expansion and contraction of the heart is called.
(v) The main excretory product in human beings is.
(vi) Sweat contains water and.
(vii) Kidneys eliminate the waste materials in the liquid form called.
(viii) Water reaches great heights in the trees because of suction pull caused by .
Tick the correct answer:
(a) The reproductive part of a plant is the
(i) leaf (ii) stem (iii) root (iv) flower
(b) The process of fusion of the male and the female gametes is called
(i) fertilisation (ii) pollination
(iii) reproduction (iv) seed formation
(c) Mature ovary forms the
(i) seed (ii) stamen
(iii) pistil (iv) fruit
(d) A spore producing plant is
(i) rose (ii) bread mould
(iii) potato (iv) ginger
(e) Bryophyllum can reproduce by its
(i) stem (ii) leaves
(iii) roots (iv) flower
What is a virtual image? Give one situation where a virtual image is formed.