Science Chapter 9 Force And Laws Of Motion

Last one year i felt sick three times. The illness were -typhoid, dysentry, viral fever.

(a) One change in habit that would avoid the illness is drinking safe and pure filtered/boiled water and avoid eating uncovered food. 

(b) One change in surroundings to avoid diseases is that there should be no accumulation of garbage and stagnant water in the surroundings.

A doctor/nurse/health-work can avoid getting sick by following these habit -:

(i) Wearing a mask  to cover mouth and nose to avoid infection when in contact with or near a diseased person.

(ii) Using gloves to avoid direct contact with wounds infections and disesed people.       

(iii) Drinking safe water and eating healthy and nutritious food to keep the immune sustem strong.

(iv)  Maintaining personal hygiene  i.e., personal cleanliness, washing hand with dettol/savlon etc. after handling equipment, clothes etc. of patients. 

(v)  Keep the surroundings clean.  

The three most ommon diseases in the neighbourhood are dysentry, malaria, viral fever.

The three preventive measures that could be taken by the local authorities are 

1. Keeping the area clean i.e., removal of garbage from the streets/ houses and storage in a covered place till it is disposed off. Proper  sanitation and cleaning of drains and proper disposal of sewer water.

2. Cleaning and removal of stagnant water and breeding places of mosquitoes like ditches with stagnant water. Pouring of oil over the stagnant water to kill the larvae of mosquitoes. Spraying of chemicals/smoke in neighbourhood to kill mosquitoes.

3. Ensure supply of safe drinking water. Regular cleaning of the water supply resources. 

(a) The symptoms like fever, loose motions, vomiting and signs like behavioural changes like constant crying, irritation etc, can tell that the baby is sick. 

(ii) The symptoms like vomoting, fever, loose motions indicate that the baby is suffering from diarrhoea. But to pinpoint the disease the baby should be taken to a doctor and further laboratory tests should be done in order to diagnose the disease.

The person is more likely to fall sick when she is on a four-day fast after recovering from malaria and is taking care of someone suffering from chicken-pox.

This is because the disease has already made the person weak, then the lack of food does not allow the person to regain health. The weak immune system is highly susceptible to catching diseases and moreover the highly infectious nature of the disese chicken pox makes the person susceptible to catching the disease. 

The most likely condition to fall sick is when our friend is having measles. 

Reason. Measles is a very infectious diesease. If we visit or meet our friend then the disease can spread through air in the form of droplet thrown in air during sneezing, coughing, nasal discharge etc. (Microbes enter through respiratory tract or conjuctiva of eye). So, we are most likely to get infected by the disease.

Food is necessary to provide energy, nutrients and raw material fto sustain the life functions. 

Health is a state of being well enough to function well physically, mentally and socially.

Garbage thrown in open places, overflowing drain water or sewer, accumulation of stagnant water in ditches etc. can cause spread of disease. These places provide the breeding grounds for disease causing microbes multiply, mosquitoes and flies breed. Thus, diseases may spread in the community and hence affect individual health adversely. Thus, it is very important to maintain public cleanliness in order to avoid catching any disease and being healthy. 

Proper and sufficient food is necessary for good health of an individual. This food will have to be earned by doing work. So, opportunity to do Proper and sufficient food is necessary for good health of an individual. This food will have to be earned by doing work. So, opportunity to do work and earn have to be available.work and earn have to be available.

Health is a state of taotal well being which means being well enough to function well physically, mentally and socially. If a person is disturbed, tensed,  stressed or depressed then the person is not mentally well. For example if a student is tensed or stressed about the results then he/she has poor health. 

The following two examples provide a proof that a person's health can depend on his environment.

(i) An unhygienic environment contaminated with disease causing micro-organisms affects health adversely, e.g., water contaminated with vibrio cholerae leads to cholera.

(ii) Polluted environment like polluted air, water etc can lead to many diseases like lung infections diseases like typhoid cholers etc. 

The organisms and populations of different species interacting between themselves and with their environment in a common habitat form a community.

Man is a social being. We live in a community. If we do not maintain personal hygiene we may fall sick and have disease. The disease that we have may be infectious and make others who live near us susceptible too. Thus we should maintain personal health by keeping ourselves clean and our house and taking balanced diet. If we are healthy we will not be the carriers of any disease or infections and thus will not affect the community health adversely. Therefore personal health is related to communty health. 

We cannot stay well if our neighbourhood is not clean. If the neighbourhood is not clean, our environment becomes unhealthy. Unhealthy environment may act as the breeding grounds for microbes or other infectious agents and thus spread diseases. An unclean environment may have polluted water and air which may affect our health adversely. 

‘Health’ is a state of being well enough to function well physically, mentally and socially. Therefore, the two conditions necessary for good health are-:

(i) Physically fit and healthy.

(ii) Happiness and social equality and harmony which are essential for individual health particularly for social and mental health.

The two conditions necessary for being free of disease are -:
(i) Maintain personal and public cleanliness.
(ii) Take proper and sufficient food necessary for a healthy immune system and body. 

The two conditions essential for being free from any disease are

(i) Balanced diet necessary for proper functioning of body and its functions. Drinking filtered/boiled water and avoiding uncovered foods. 

(ii) Maintaining personal hygiene and cleanliness. 

Answers to the above questions 1 and 2 are different. This is because health and disease are different from each other. When we think about disease, we think about individual sufferers, whereas when we think about health, we think about societies and communities.  Health means a state of being well enough to function well physically, mentally and socially. Diesease-free is being free from any discomfort. It may be possible to be in poor health without suffering from a particular disease. Thus the conditions for healthy and disease free may not be the same. 

Symptoms of diseases indicate that there is something wrong. Therefore symptoms like fever, cough cold, pain etc can tell ud that we are suffering rom diseases. But they cannot indicate what the disease is. 
Signs of disease indicate the specific disese. The physicians for signs of diseses to pinpoint the diseases.

By getting laboratory tests done we can pinpoint a disease. 

Chronic diseases.

(i) Immediate cause of disease are infectious organisms like virus, bacteria, fungi, protozoan etc. 

(ii) Contributory causes of disease are :

(a) Poor health due to lack of good nourishment.

(b) Poor hygiene condition, economic condition due to which one does not get proper and sufficient food.

(c) Genetic difference which make some people more prone to disease than others.

The causes of disease are -:

(i) Infection

(ii) Poor or polluted environment. 

(iii) Lack of proper nutrition.

(iv) Poor sanitations and improper personal hygiene. 

(v) Drinking impure water or eating uncovered food. 

Genetic differences is responsible for it. The baby who suffered from loose motion was more susceptible to the disease due genetic difference.

Disease caused by infectious agents and which can be spread are called infectious diseases. These can be spread by contact, aerosols in the air due to sneezing or cough etc. For example - measles, chicken pox etc. 

The two major categories of human diseases are:

(i) Infectious diseases and

(ii) Non-infectious diseases.

(i) Infectious diseases—Malaria, Flu, Jaundice etc.

(ii) Non-infectious diseases—Diabetes, Cancer, etc.

If I have these symptoms : constant headache, high fever, loose motions. 

Even seeing one symptom, I will go to doctor.

Reason. A single symptom is the sign of a disease. On delaying it may lead to serious illness. For example, headache may mean meningitis.

The effects will be most unpleasant in the case of jaundice because it is a chronic disease and takes long time to be cured. Moreover, jaundice affects the whole body and it takes long time to be healthy.

The group of organisms which cause infectious disease are 

(i) Viruses (ii) Bacteria (iii) Fungi

(iv) Protozoans (v) Some multicellular worms.

The common diseases caused by viruses are

(i) common cold (ii) dengue fever

(iii) influenza (iv) AIDS.

Diseases caused by bacteria

(i) Typhoid (ii) Cholera (iii) Tuberculosis (iv) Anthrax.

Disease like common skin infections are caused by different fungi.

Protozoan.

Worms.

Members of a single group have common traits i.e., many biochemical processes inside their cells are similar. As a result, the drug block these biochemical pathway and result in the killing of the microbe. However the different group of microbes do not share the same biochemical pathways and hence the rug has no effect on them. Since the same drug cannot block the different biochemical pathways in different groupps , same drug will not be effective against a microbe belonging to a different group.

Antibiotics commonly work by blocking the biochemical pathways important for bacteria. Thus these inhibit the growth of bacteria , hamper their metabolism and kill them.

Antibiotics do not work on viruses because viruses do not use the biochemical path thus the antibiotics have no effect on viruses.

Doctors prescribe antibiotics in case of common cold to kill any bacteria and to prevent or treat any bacterial infection during the cold. 

Common cold, pneumonias and tuberculosis can spread through air. These are infectious diseases and spread by the means of little aerosol droplets thrown out by an infected person during sneezing or coughing. The microbes in these droplets enter a healthy person and infects them. 

Drinking water which is polluted with the disease causing microbes causes diseases. When the excreta of an infected person gets mixed with the drinking water. The infectious microbes present in the water enter the new hosts with drinking watera nd cause the infection. This is how the diseases spread through water.

None of the physical activities like handshake, hugs or wrestling can spread AIDS. 

The organisms that carry the infectious agents from a sick person to a potential host or healthy person are called vector. These organisms are responsible for the spread of the diseases. 

Anopheles mosquito.

Different microbes after entering into the body target different organs or tissues. Due to infection there is change in functioning that lead to manifestation of different signs and symptoms.

Inflammation - is the response of the immune system to the affected tissue by recruiting many cells to kill the disease causing microbes.

The inflammation response leads to common effects like swelling, pain and fever.

The two ways to treat an infectious disease are:

(i) By reducing the effect of the disease and
(ii) By killing the cause of the disease.

Making anti-viral medicines is harder than making anti-bacterial medicines. This is because viruses have very few biochemical pathways of their own, which can be targeted. Viruses depend on their host to complete all the biochemical reactions, thus with little pathways of their own, the anti-viral medicnes cannot target and kill them. 

Prevention is better than cure because:

(i) Once someone has a disease is affects the body adversely and sometime the body never recovers completely.

(ii) Treatment takes time which means the patient is likely to be bedridden for sometime even when he/she is given proper treatment.

(iii) The person suffering from an infectious disease can serve as the source for the spread of the disease. 

Preventive measures of infectious diseases are -:

(i) We can prevent exposure to air borne diseases i.e., providing living conditions that are not overcrowed.

(ii) We can prevent exposure to water borne microbes by providing safe drinking water free from contamination.

(iii) We can presvent vector-borne infections, by providing clean environment that is abolishing breeding places of mosquitoes and flies.

(iv) Avoid contact in case of disease like measles and chichken pox. Avoiding close physical contact in case of diseases like AIDS.

(v) By making the body immune system strong by having proper and sufficient nourshing food.

When a person suffers from small pox once, the immune system of our body encounters the disease and responds against it. Our immune system remembers the first encounter and response specifically. Theefore, when the next time that particular microbe or its close relatives enter the body, the immune system of the body respond with even greater vigour. This eliminates the infection more quickly than the first time around and we do not aquire the disease.

Four diseases for which immunisation vaccine are available are
(i) Tetanus,
(ii) diptheria,
(iii) whooping cough and
(iv) measles/polio.

Infectious disease show a lack of success of the immune system of the body. It adversely affects are metabolism too. For the proper  functioning of immune system our body needs sufficient nourishment and easily digestable food is necessary for a sick person. Bland food is full of nourishment but devoid of spices which can be heavy to digest and thus are easily digestable and provide our body the much needed nourishment to boost the immune system. 

Infectious disease can be spread in the following ways : 

(i) By Air - Sneezing or cough little droplets thrown in the air carry micrrobes which can cause the spread. For example in common cold, pneumonia etc.

(ii) Water - Contaminated water carry disease causing microbes which can cause infection o. Example, gut diseases such as cholera.

(iii) Sexual Contact. Diseases such as syphilis or AIDS are transmitted by sexual contact.

(iv) By vectors  These are intermediaries which carry the infectious agents from the patient to the host (normal person). Example, mosquitoes (Female Anopheles mosquito) can cause spread of malaria.

Precautions that we can take in our school to reduce the incidence of infectious diseases are :

(i) Avoid overcrowded place.

(ii) Dring pure and safe water..

(iii) Maintain cleanliness on a personal and public level.

(iv) Using of handkerchief or towel to cover the mouth and nose while a infected student is sneezing or coughing.

(v) Using of clean toilets.

(vi) Not to allow water to stagenate in school or around school to avoid mosquito breeding.

(vii) To get vaccinated whenever programmes are organised in the school for inocculation against various diseases.

(viii) Not eating food exposed to flies, mosquitoes etc.

(ix) Eating proper and nutritious food for a strong immune system.

Introduction of mild type of infection (microbes) or killed infectious microbes into the body by vaccination/by other means to activate the immune system against a particular infection/disease is called immunisation.

Immunisation programmes available at the nearest healthcare centre in the locality are : 

(i) Vaccination against small pox.

(ii) BCG vaccination against tuberculosis.

(iii) Polio drops against polio disease.

(iv) Vaccination against chicken pox.

(v) Vaccination against Hepatites.

(vi) DPT vaccination against diptheria, pertusis (Whooping Cough) and tetanus.

(vii) Immunisation against measles.

The major health problems are:

(i) Hepatitis (ii) Chicken pox (iii) Tuberculosis (iv) Tetanus.

(i)  Cereals - provide us with carbohydrates. They fulfill our energy requirements. Wheat, rice, maize are cereals.
(ii) Pulses -  provide proteins, Gram, pea and lentil are pulses.
(iii) Fruits and vegetables provide vitamins and minerals. They also provide small amount of  proteins, carbohydrates, and fats are also present in them.

Biotic factors such as pests, insects and diseases reduce the crop production. These adverse effect on the plants and thus decrease the production. A pest causes damage to our crops by feeding. Weeds also reduce crop productivity by competing with the main crop for nutrients and light.
Similarly, abiotic factors such as temperature, wind, rain, drought, salinity etc. affect the net crop production. For example droughts and floods have a great impact on crops sometimes, destroying the entire crop. Salinity can lead to the death of crops if they are not resistant to it. 

The desirable agronomic characteristics for crop improvements are:
(i) Tallness and profuse branching for the fodder crop.
(ii) Dwarfness in cereals, so that the crops consume less nutrients.

Macro-nutrients are those nutrients which are required in large quantities for growth and development of plants. They are so called as they are required in large quantities. There are six macro-nutrients that are required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.

Plants get nutrients from air, water, and soil. Soil is the major source of nutrients. Thirteen of these nutrients are available from soil. Plants absorb nutrients along with the water from the soil. The remaining three nutrients (carbon, oxygen, and hydrogen) are obtained from air and water.

(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
These conditions will give the most benefits as:
Good quality seed will increase the crop production and quality. The seeds will results in higher yield, wider adaptability, resistance to abiotic and biotic stresses etc.
Use of Fertilizer will ensure good vegetative growth and healthy plants.
Use of crop protection measures will ensure the control of weeds, pests, and infectious agents. 

Preventive measures and biological control methods should be preferred for protecting crops because excessive use of chemicals leads to environmental problems like pollution. Chemicals are also poisonous for many plant and animal species. The biological method does not cause pollution and are not toxic to the other organisms. Preventive measures minimizes the chances of pests or diseases to infect the plants and thus protects the crops. 

Factors causing loss of grains during storage:
(i) Biotic Factors: These include insects, rodents, fungi and bacteria etc. These organisms eat the grains and lead to degradation in quantity, quality weight etc.
(ii) Abiotic Factors: These include the inappropriate moisture content and temperature which result in the loss of quantity and quality of grains. 

Cross Breeding is commonly used for improving cattle breeds. It is the method in which an Exotic breed selected for long lactation period is crossed or mated with the Local breed that show excellent resistant to diseases. The Cross breeding will produce a new improved variety with desired qualities. For example, the cross between foreign breeds such as Jersey Brown, Swiss and Indian breeds such as Red Sindhi, Sahiwal.  

Poultry in India is the most efficient converter of low fibre food stuff into highly nutritious animal protein food. In poultry farming, domestic fowls are raised to produce eggs and chicken. For this, the fowls are given animal feeds in the form of roughage, which mainly consists of fibres. Thus, by feeding animals a fibre rich diet, the poultry gives highly nutritious food in the form of eggs and chicken.

Common management practices in dairy and poultry farming are:
(i)  Proper shelter facilities and their regular cleaning.
(ii) Maintaining proper hygienic conditions such as clean water, nutritious food, etc.
(iii) Prevention and cure of diseases at the right time is ensured.

Layers are meant for egg production, whereas broilers are meant for poultry meat. The housing, environmental and nutritional conditions required by broilers are different from those required by egg layers.  The daily food requirement for the broilers should be rich in protein and adequate fat. A broiler requires vitamin rich supplements especially vitamin A and K. They also require extra care and maintenance to increase their survival rate in comparison to egg layers.

Fish are obtained by two ways:
(i) Capture fishing – obtaining fish from the natural resources.
(ii) Culture fishery: It is the practice of farming fishes. 

The advantages of composite farming are:
(i) Intensive fish farming can be done.
(ii) Local and imported fishes can be used and kept together.
(iii) The fish yield is increased. 

Bee varieties having the following desirable characters to be suitable for honey production:
(i) High yield - They should yield high quantity of honey. The bee varieties reared should produce more honey. 
(ii) Less Stings - They should not sting much. bees reared should sting less so that they can be reared easily and the honey can be obtained easily.
(iii) Long stay - They should stay in the beehive for long durations.
(iv) Good breeding - They should breed very well.

Pasturage is the availability of flowers from which bees collect nectar and pollen. It is related to the production of honey as it determines the taste and quantity of honey.

The different method of cropping pattern can help in increasing the yield of the crop. Methods like Inter cropping in which the farmer grows two or more crops simultaneously in the same field in rows. In inter cropping definite row patterns are followed such as one row of main crop of is followed by two row of intercrop. This method ensures greater utilisation of the interspaced area, light, nutrients, water and air. As a result productivity per unit area increased.

Manures and fertilizers are used in fields to enrich the soil with the required nutrients, improve fertility of the soil and crop yield and quality. Manure helps in enriching the soil with organic matter and nutrients. This improves the fertility and structure of the soil. On the other hand, fertilizers ensure a healthy growth and development in plants. They are a good source of nitrogen, phosphorus, and potassium. A balanced combination of manures and fertilizers in the soil should be used, to get an optimum yield.

Inter-cropping and crop rotation both are used to get maximum benefit on limited land.
Inter-cropping ensures maximum utilisation of the nutrients supplied. It helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility.
Crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion.
Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.

Genetic manipulation is a process in which the gene for a desired character is introduced inside the cell of a plant. The incorporation of a new gene in to the new plant produces a transgenic plant which exhibits the desired characters.
Genetic manipulation is useful as it allows new varieties with desired characters to be produced. It allows in the production of plants with higher yield, good quality, biotic and abiotic resistance, short maturity period, wider adaptability and desirable agronomic characteristics.

The storage grains loss can occur due to the following reasons:
(i) Biotic factors – like insects, rodents, fungi, mites and bacteria. These organisms infect the grains and degrade the quantity  and quality of the grains.
(ii) Abiotic factors- Various factors like inappropriate moisture, temperature can lead to loss of grains and their discolouratiion, loss in weight etc.   

Good animal husbandry practices produce drought animals that can be used for the agricultural purposes like tilling, irrigation and carting.  The draught animals perform these works and make the work easy for the farmer. 

Benefits of cattle farming:
(i) High yield - Good quality and quantity of milk can be produced.
(ii) Farm labour - Draught labour animals can be produced for agricultural work like tilling irrigation and carting.
(iii) New variety that are high yielding and resistant to diseases can be produced by crossing two varieties with the desired traits.

Proper management technique is a common factor for increasing production in poultry, fisheries, and bee. Management techniques like regular cleaning of farms is of utmost importance. Maintenance of temperature and prevention and cure of diseases of the farmed organisms is also required to increase the number of animals and the yield.

(i) Capture fishing the method of obtaining fishes from natural resources.
(ii) Mariculture is the culture of marine fishes for commercial use. It is the farming of marine fish of high economic value in seawater. For examples the farming of finned fishes like mullets, bhetki, pearl spots etc.
(iii) Aquaculture involves the production of aquatic animals that are of high economic value such as prawns, lobsters, fishes, crabs, etc.