Class 9th ICSE Biology Solutions Chapter 15 Hygiene [A Key to Healthy Life]
Question 1.
Fill in the blanks :
(i) Cleanliness, rest and sleep, and physical exercise are apart of …………….. hygiene.
(ii) One must always breathe by the …………… and never by the ……………..
(iii) Fresh air brings …………… into the living rooms.
(iv) One must never put a sharp-pointed object into the ……………. it may rupture the
(v) For adults 6-7 hours of continuous undisturbed …………… is sufficient.
(vi) The municipal bodies must ensure the supply of clean germ-free …………… and an efficient…………… disposal.
Answer:
(i) Cleanliness, rest and sleep, and physical exercise are a part of personal hygiene. ‘
(ii) One must always breathe by the nose and never by the mouth.
(iii) Fresh air brings oxygen into the living rooms.
(iv) One must never put a sharp pointed object into the ear it may rupture the eardrum.
(v) For adults 6-7 hours of continuous undisturbed sleep is sufficient.
(vi) The municipal bodies must ensure the supply of clean germ- free drinking water and an efficient sewage disposal.
Question 2.
List any three advantages of a daily bath.
(i) ……………..
(ii) ……………..
(iii) ……………..
Answer:
- Keeps skin clean and free of germs.
- Body odours given out in perspiration are removed.
- Keeps the sweat pores open.
PROGRESS CHECK
Question 1.
Tick-mark the correctly matched pairs of certain animals and the related diseases/habits.
(i) Culex …………….. yellow fever
(ii) Aedes …………….. filaria
(iii) Anopheles …………….. malaria
(iv) Gambusia ……………..eat up mosquito larvae
(v) Rat flea …………….. diarrhoea
(vi) Cockroaches …………….. Breed in man-holes
Answer:
(iii) (✓) (iv) (✓) (vi) (✓)
PROGRESS CHECK
Question 1.
Mention if the following statements are True (T) or False (F)
(i) Contamination means entry of germs by insect bite. T/F
(ii) Sewage is the commonest source of contamination of water in the cities. T/F
(iii) Cholera is marked by acute diarrhoea and no urination. T/F
(iv) Typhoid is caused by a type of worm. T/F
(v) Mosquitoes are the source of dysentery germs T/F
Answer:
(i) F (ii) T (iii)T (iv)F (v)F
REVIEW QUESTIONS
A. Multiple Choice Type :
Question 1.
No urination due to shortage of water in the body is a typical symptom of
(a) typhoid
(b) cholera
(c) dysentery
(d) malaria
Answer:
(d) cholera
Question 2.
Which one of the following is an unhealthy habit?
(a) Removing wax from inside the ears
(b) Keeping the mouth closed while breathing
(c) Sleeping for only 6-7 hours
(d) Sharing towels with other
Answer:
(d) Sharing towels with other
Question 3.
The prozoan that causes malaria is :
(a) Entamoeba histolytica
(b) Euglena
(c) Paramecium
(d) Plasmodium
Answer:
(d) Plasmodium
Question 4.
The chemical substance mainly responsible for tooth disorders is
(a) calcium
(b) chloride
(c) flourides
(d) iodides
Answer:
(c) flourides
Question 5.
Thyphoid is caused by
(a) housefly
(b) bacteria
(c) virus
(d) None of the above
Answer:
(b) bacteria
Question 6.
The germ causing Hepatitis is transmitted through :
(a) the bite of a mosquito
(b) contamination of food by a housefly
(c) personal contact with a patient
(d) contaminated water
Answer:
(d) contaminated water
B. Very Short Answer Type
Question 1.
Match Column I with that which is most appropriate the Column II :
| Column I | Column II |
| (a) Mosquito | (i) DDT |
| (b) Plasmodium | (ii) Dengue |
| (c) Entamoeba histolytica | (iii) Vector |
| (d) Aedes mosquito | (iv) Malaria |
| (e) Insecticide | (v) Dysentery |
Answer:
(a) (iii) (b) (iv) (c) (v) (d) (ii) (e) (i)
Question 2.
Name the following :
(a) Organism that transmit microbes that cause disease.
(b) Organisms that cause disease.
(c) Science of maintaining good health.
Answer:
(a) Pathogens,
(b) Tuberculosis,
(c) Hygiene
Question 3.
Describe the different ways by which the housefly contaminates our food.
Answer:
The manner in which the housefly contaminates our food
(i) Hair, body and legs pick up filth and contaminate our food.
(ii) Moistens the foodstuff by pouring out its saliva.
(iii) Deposits its excreta while it feeds and thus, contaminates human food.
Question 4.
Suggest any two methods of controlling flies.
Answer:
Two methods of controlling flies
- Elimination of breeding places like-refuse, animal and human excreta be removed at regular and frequent intervals.
- spraying with D.D.T. and other insecticides
Question 5.
List any three effective methods for controlling mosquitoes.
Answer:
Methods to Control mosquitoes—
- Spraying -D.D.T. and insecticides in dwelling places like – ponds, marshes, stagnant water.
- Elimination of breeding place-e.g., Small ponds, puddles.
- Biological control-Gambusia (fish)-Devour mosquito larvae.
Question 6.
Name the two common kinds of mosquitoes and the diseases they transmit.
Answer:
- Mosquito Disease
- anopheles Malaria
- Culex Filaria
Question 7.
Mention any three ways by which potable water can be contaminated.
Answer:
Contamination of potable (drinking) water can occur in several ways such as :
- Sewage if improperly disposed of, leaks into sub soil and may contaminate water supplies.
- People defecating or urinating near lakes, rivers or ponds may contribute to contamination of water.
- Animal wastes and washings from dairies, poultries, etc. may also be drained into water bodies.
Besides the above principal sources of contamination, there can be a variety of industrial and agricultural wastes that may contain poisonous chemicals and can be harmful to human health.
C. Long Answer Type
Question 1.
Give suitable explanations for the following :
(i) One should breathe by nose and never by mouth.
(ii) Hands must be washed before eating food.
(iii) Eating places must be kept free of flies.
Answer:
(i) One must always breathe by the nose, as nose contains hair which help to filter the air clean and remove germs.
(ii) We are continuously handling a variety of things like – furniture, books etc. AH objects may carry germs which may be picked by our fingers and transferred over other parts of the body into the mouth through food. Hence, practice of washing hands with soap is very important.
(iii) Flies are carriers of germs and bacteria hence eating places must be kept free of flies.
Question 2.
How are cockroaches and rats harmful to humans?
Answer:
Cockroaches
- They eat and spoil food, paper and clothes.
- They are also suspected to be carriers of certain viral diseases including cancer-causing virus.
Rats
- Eat food grains and other food.
- They also spread germs of certain diseases.
- Rat- flea is a parasite on rat’s skin that carries germs of plague.
Question 3.
Name the two types of dysentery and their causative germs and give one main precaution against them.
Answer:
Two types of dysentery are
- bacillary
- amoebic.
- Bacillary dysentery: The causative agent is a bacterium (Shigella). It occurs frequently among children. The disease is marked Prevention includes drinking safe (boiled) water and avoiding flies from contaminating food.
- Amoebic dysentery: The causative agent is a protozoan Entamoeba histolytica.
This organism enters our body through contaminated water and food. It establishes in the lining of large intestine where it feeds by engulfing red blood cells of the patient’s intestine.
Proper sanitation and personal hygiene are extremely important in controlling this disease. Persons infected with chronic amoebiasis should be isolated and treated. All raw vegetables and fruits should be thoroughly washed before use as cysts are often picked up by flies from exposed faeces.
Question 4.
Mention three symptoms of the disease Hepatitis.
Answer:
- Body ache.
- Eyes yellowish, deep yellow urine (due to bile pigments).
- Enlarged liver.
Additional Questions
Question 1.
It is important to make sure that swimming pool water is clean.
Answer:
Infection of ears and nasal passages and throat are common from the swimming pools. The persons who visit the swimming can easily be infected by these diseases through infected water of the swimming pools. They may get infection of the skin easily. To avoid these diseases the infected person should not be allowed in the swimming pools as those persons can infect the water.
These are communicable diseases and transmission of these diseases is possible as these are communicable diseases and transmission of these diseases is possible as there are germs in the water. The water of the swimming pool should be replaced frequently and the swimming pools should be disinfected by the use of the DDT and other disinfectants. The person should have a bath in the bathrooms before, Swimming in the swimming pool. Swimming pool should be kept clean.
Question 2.
There should be no stagnant water near your house.
Answer:
The stagnant water near the houses will become breeding ground for the mosquitoes. They can give egg and it is easily for them to pass their life cycle and form new adult mosquitoes those mosquitoes easily breed. These mosquitoes cause malaria through the plasmodium which it leaves in the blood stream as these suck blood from the human beings. These protozoa can easily pass their cycle in the two hosts.
The sexual cycle is passed in the mosquito and asexual cycle is passed in the human beings. The female anopheles mosquito spreads this dreadful disease the malaria. In the human beings it infects the RBCs and as large number of RBCs are used and toxin are left in the blood and as a result they gets fever. So there should not be stagnant water near the houses. We should spray DDT and other insecticides in the standing water so that it does not become breeding ground for the mosquitoes.
Question 3.
Cigarette smoking is injurious to health.
Answer:
The cigarette smoke contains nicotine, tar and carbon monoxide. The cigarette smoking causes increase in the blood pressure. It may cause irritation of nose, throat and cough.
He suffer from lung cancer breathing problems and darkening of teeth. Nicotine in the tobacco makes habit forming. Once a person starts smoking it is very difficult to leave it. The person becomes chain smoker. Respiratory diseases arise. Lungs get damaged. He may get T.B. or lung cancer or mouth cancer or neck cancer. It leads to painful death.
Question 4.
Explain the various ways through which communicable diseases spread?
Answer:
Spread of Communicable diseases
1. Air borne infection Bacteria and viruses are very tiny one-celled microscope organisms. These infect nasal passage, throat, windpipes and lungs. Infected people when sneeze or cough at public places. They spray crores of bacteria and viruses in the air and The persons sitting to close to them catch the disease. So it spreads through it as in diphtheria, whooping cough. Cold influenza.
2. Water borne infections Typhoid, dysentery, cholera are internal infections and spread through the intake of dirty, infected water. Swimming pools spread infections of throat, ear, nasal passages and skin.
3. Infections through the food Intestinal infections spread through unwashed fruits, vegetables, food prepared by infected persons at the parties weddings may cause infections to so many persons. It may cause amoebic dysentery and diarrhoea. Bacteria can enter through the canned fruits and jams and spoil them and leave toxins in them. If taken then cause many intestinal diseases.
4. Infection through contact Many infections are carried by direct contact from person to person as athletes foot. It is a fungal disease which spreads through contact. Intestinal infections and many viral infections are in the family from one person to others. Conjunctivitis can spread through the contact to whole of the class.
Question 5.
What is botulism?
Answer:
It is type of food poisoning. It takes place by taking spoiled canned food. The bacteria gets entry into the canned food, fruits or jams. These bacteria multiply in the absence of air and leave toxic substances in the canned food which is harmful for the nervous system. It may cause diseases of the stomach as food poisoning, dysentery.
ICSE Class 9 Biology Solutions