The Class 8 is an important year in a student’s life and Maharashtra State Board Science is one of the subjects that require dedication, hard work, and practice. It’s a subject where you can score well if you are well-versed with the concepts, remember the important formulas and solving methods, and have done an ample amount of practice. Worry not! Home Revise is here to make your Class 8 journey even easier. It’s essential for students to have the right study material and notes to prepare for their board examinations, and through Home Revise, you can cover all the fundamental topics in the subject and the complete Maharashtra State Board Class 8 Science Book syllabus.
Question 1: Distinguish between –Infectious and non-infectious diseases.
Answer:
| Infectious diseases | Non-infectious diseases |
| 1. It can be transmitted from one individual to another. | It cannot be transmitted from one individual to another. |
| 2. It is mainly caused by a pathogen. | It is caused due to internal reasons, such as metabolic, hereditary or genetic reasons. |
| 3. They are also known as communicable diseases. | They are known as non-communicable diseases. |
| 4. Examples: diarrhoea, tuberculosis, cholera, etc. | Examples: hypertension, diabetes, cancer, etc. |
Question 2: Identify the odd term.
a. Malaria, hepatitis, elephantiasis, dengue.
b. Plague, AIDS, cholera, T.B.
Answer: a. Malaria, hepatitis, elephantiasis, dengue: Among all these diseases, Hepatitis is the odd one because it is caused by a virus while the rest of three usually spread through mosquito bites.
b. Plague, AIDS, cholera, T.B.: Among all these diseases, AIDS is the odd term because it is caused by a viral infection while the rest of the diseases are caused by bacteria.
Question 3: Answer in one to two sentences.
a. Which are various media of spreading the infectious diseases?
b. Give the names of five non-infectious diseases other than given in the lesson.
c. Which are the main reasons for diabetes and heart diseases?
Answer: a. Infectious diseases usually spread through water, air, human blood to blood transfusion and animal vectors.
b. Non-infectious diseases include cataract, arthritis, osteoporosis, multiple sclerosis, Parkingson’s and Alzheimer ’s disease.
c. Some of the reasons for diabetes include obesity, lack of physical activity, mental anxiety &stress, imbalanced diet and genetic causes.
Some of the reasons for heart diseases include heavy smoking, drinking, hypertension, diabetes, obesity, lack of physical activity, mental anxiety &stress and imbalanced diet.
Question 4: What can be achieved / can be prevented ?
a. Drinking boiled and filtered water.
b. Avoiding smoking and alcoholism.
c. Regular balanced diet and exercise.
d. Proper checking of blood before blood donation.
Answer: a. Boiling and filtration are useful methods of purifying water that renders it suitable for consumption. Drinking boiled and filtered water can prove helpful in prevention of various water-borne diseases such as typhoid fever, cholera, etc. Most of the water-borne diseases are caused due to the consumption of contaminated water in some form or the other.
b. Smoking and alcoholism are two major causes of health problems which affect our society greatly. Smoking leads to different kinds of respiratory disorders and hinders the respiration process in humans. It can lead to acute health diseases such as lung cancer, throat cancer, etc. On the contrary, consumption of alcohol affects the liver, nervous and digestive system of our body. People can maintain a healthy lifestyle and stay protected from various diseases by avoiding alcohol and smoking in their lives.
c. Having a balanced diet and proper exercise are key factors which contribute to good health. When both are combined together, it helps our systems to function properly, maintain a healthy body mass and weight, reduces body fat, provides energy, promotes sound sleep and makes us feel fresh and fit about ourselves.
d. Proper checking of blood before blood donation is important to check the blood thoroughly before it is transferred to others. Many a time, there are chances of transmission of infectious diseases from the donor to the recipient in case the former is suffering from any such diseases. One more important reason, it is important to check blood before donation is to examine that the donor is not anaemic as donating blood may be harmful to him/her.
Question 5: Read the passage and answer the questions.
Master ‘X ’is a 3 year old child. He is living with his family in a slum. Public toilet is present near his house. His father is a drunkard. His mother does not know the importance of a balanced diet.
a. Master ‘X ’can suffer from which different possible diseases in above conditions ?
b. How will you help him and his family in this situation ?
c. Which disease can occur to the father of master ‘X ’?
Answer: a. Since, the house of master X is in a slum area and there is a public toilet near it, there are chances that there is a lack of cleanliness in that area. He is likely to suffer from diseases like shigellosis, salmonellosis, diarrhoea, gastroenteritis, giardiasis, trachoma, tapeworm infection or threadworm infection.
b. In this case, the family needs to maintain personal hygiene and cleanliness in and around their houses. They should be explained about the importance of a balanced diet for the entire family. Since, the father is a drukyard, he needs proper counselling, rehabilitation and treatment to get rid of this ill-habit of alcoholism.
c. Since the father of master X is a drunkard, he is likely to suffer from complex diseases such as liver cirrhosis, heart diseases, ulcers and gastrointestinal problems, brain haemorrhage, etc.
Question 6: Give the preventive measures of the following diseases.
a. Dengue
b. Cancer
c. AIDS
Answer: a. Dengue is a disease which is transmitted by Aedes mosquito which lays eggs in water-logged places, which multiply over time. Mosquitoes breeding can be prevented by adopting the following measures:
b. Preventive measures for cancer:
c. Preventive measures for AIDS are:
Question 7: Explain the importance.
a. Balanced diet.
b. Physical exercise / Yoga asanas.
Answer: a. A balanced diet is a diet that consists of all essential nutrients such as proteins, carbohydrates, fats, vitamins and minerals in the right proportion. A balanced diet helps us in the following ways:
b. Importance of exercise and yoga asanas are:
Question 8: Make a list.
a. Viral diseases.
b. Bacterial diseases.
c. Diseases spread through insects.
d. Hereditary diseases.
Answer:
| Type of Diseases | Examples |
| Viral diseases | Chicken pox, Mumps, Measles, Swine flu, etc. |
| Bacterial diseases | Diphtheria, Tuberculosis, Cholera, Tetanus, Typhoid, etc. |
| Diseases spread through insects | Malaria, Dengue, Plague, etc. |
| Hereditary diseases | Hypertension, Diabetes, Cancer, etc. |
Question 9: Write the information on modern diagnostics and treatments of cancer.
Answer: Diagnostics of cancer: There are various techniques which are used in the diagnosis of cancer. The application completely depends upon the type of cancer. Radiography (use of X-rays), biopsy, CT Scan (Computed Tomography), histopathological studies of bone and blood and MRI (Magnetic Resonance Imaging) are mostly used in the diagnosis of cancer. Some of the modern techniques such as Radiography, CT Scan and MRI are used in cancer diagnosis.
1. MRI uses strong magnetic rays and non-ionising radiations to accurately detect and identify pathological and physiological changes in the living tissue or body.
2. CT Scan uses X-rays to generate a three-dimensional image of the internal parts of a particular object or human body.
Treatment of cancer: Cancer can be treated by using three major approaches based upon the type of cancer. These approaches include surgery, radiotherapy and chemotherapy.
1. In surgery, the tumor is removed from its site through operation and is applicable in specific body regions and cases only.
2. Radiotherapy is a technique in which the cancer cells are damaged with radiations and take care of the normal tissues surrounding the cancer cells.
3. Chemotherapy uses various types of drugs for treating cancer. These chemotherapeutic drugs can be used specifically for particular tumors only and they have a lot of side effects such as hair loss, paling of skin, anaemia, etc.
Most of the cancers can be treated by using a combination of all these three approaches.
Question 10: Enlist the names and composition of the medicines present at your home.
Answer: The following medicines are found in our houses:
1. For treating influenza, we generally use Paracip –Paracetamol or Acetaminophen.
2. For treating minor stomach aches and disorders, we use Digene, Polycrol, Pudin Hara, etc.
3. For treating body aches we use Volini, Moov, Iodex, etc.
(Note: Students can write this answer as per the availability of medicines at their homes.)
Question 1: Define health.
Answer: Health is defined as the state of complete physical, mental and social well-being and not just the absence of any disease in a particular body.
Question 2: What is a disease?
Answer: A disease is a condition of disturbances in physical and psychological processes of the human body. Every disease has a different set of specific symptoms.
Question 3: Explain the different types of diseases.
Answer: The symptoms of different types of diseases are specific and usually differ from one another. Let’s understand the types of diseases through a diagram:
Question 4: What do we mean by pathogen?
Answer: A pathogen is something that causes a particular ailment or disease such as a virus like rhinovirus, which is the common cause of influenza or common cold.
Question 5: What do we mean by infectious diseases?
Answer: Diseases that spread through contaminated food, air, water, vectors (insects and other animals) are known as infectious diseases.
Infectious diseases are caused by:
1. transmission from one person to another.
2. a pathogen.
They are also known as communicable diseases. Some examples include diarrhoea, tuberculosis, cholera, etc.
Question 6: What is the mode of infection, symptoms, prevention and treatment of tuberculosis?
Answer: Tuberculosis is caused by the pathogen named Mycobacterium tuberculae . Given below is mode of infection, symptoms, prevention and treatment of tuberculosis:
1. Mode of infection: Spitting by patient in the open, through air, prolonged contact with and sharing of materials of the patient.
2. Symptoms: Chronic cough, bloody spitting, emaciation, difficulty in breathing.
3. Prevention and treatment: Regular medication like DOT, BCG vaccine, isolation of the patient, etc.
Question 7: Explain the mode of infection, symptoms, prevention and treatment of Hepatitis (Jaundice).
Answer: Hepatitis (Jaundice) is caused by the pathogen called Hepatitis virus- A, B, C, D, E . Given below is mode of infection, symptoms, prevention and treatment of Hepatitis (Jaundice):
1. Mode of infection: Consumption of contaminated water, sharing of syringes and needles, blood transfusion.
2. Symptoms: Anorexia, yellow urine, swelling of liver, abdominal pain, general weakness, nausea, vomiting, grey stool, etc.
3. Prevention and treatment: Drinking boiled water and maintaining proper hygiene by cleaning of hands regularly.
Question 8: How is Malaria caused?
Answer: Malaria is mainly caused and spread in human beings when a female Anopheles mosquito bites which usually breed in stagnant water.
Question 9: Explain the mode of infection, symptoms, prevention and treatment of Cholera.
Answer: Cholera is caused by the pathogen called Vibrio cholerae (bacterium). Given below is mode of infection, symptoms, prevention and treatment of Cholera:
1. Mode of infection: Consumption of contaminated food and water.
2. Symptoms: Vomiting, severe diarrhoea, cramps in legs etc.
3. Prevention and treatment: Maintaining proper hygiene, avoiding open place food, drinking boiled water, vaccination against cholera.
Question 10: How is elephantiasis caused?
Answer: Elephantiasis is caused by the bite of a female Culex mosquito which breeds in dirty and sewage water.
Question 11: What is the mode of infection, symptoms, prevention and treatment of Typhoid?
Answer: Typhoid is caused by the pathogen called Salmonella typhi (bacterium). Given below is mode of infection, symptoms, prevention and treatment of Typhoid:
1. Mode of infection: Consumption of contaminated food and water.
2. Symptoms: Anorexia, headache, rash on abdomen, dysentery, fever up to 104°F.
3. Prevention and treatment: Drinking clean water, vaccination, proper disposal of sewage.
Question 12: Explain the causes of Dengue.
Answer: Dengue is caused by DEN-1 –4 virus belonging to the type- flavivirus. It happens when mosquitoes lay the eggs in water-logged places and gradually their population multiplies. Dengue is spread by Aedes aegypti.
Question 13: What are the symptoms of Dengue?
Answer: Given below are the symptoms of Dengue:
1. Acute fever and headache, nausea and vomiting.
2. Pain in the eye socket is a key symptom of Dengue.
3. There is a sudden decrease in platelet count which may lead to internal haemorrhage.
Question 14: What are the reasons for Swine Flu infection?
Answer: Some of the reasons for Swine Flu infection are listed below:
1. It transmits from pigs to human beings.
2. The Swine Flu viral infection is spread through secretions of nose, throat and saliva.
Question 15: What is the mode of infection, symptoms, prevention and treatment of Dysentery?
Answer: Dysentery is caused by the pathogen called Bacteria, virus, Shigella, bacilli, Entamoeba histolytica . Given below is mode of infection, symptoms, prevention and treatment of Dysentery:
1. Mode of infection: Consumption of contaminated food and water.
2. Symptoms: Watery stool, abdominal pain, etc.
3. Prevention and treatment: Drinking of boiled water, proper storage of food, ORS consumption, etc.
Question 16: When was the first case of Swine Flu reported?
Answer: In 2009, the first case of Swine Flu was reported in Mexico. This disease is caused by the viral influenza A (H1N1). People who come in contact with pigs are likely to contract this disease.
Question 17: What are the major symptoms of Swine Flu?
Answer: Some of the major symptoms of Swine Flu include:
1. Difficulty in breathing.
2. Sore throat, acute body ache with body temperature.
Question 18: How is the diagnosis of Swine Flu done?
Answer: For the diagnosis of Swine Flu, a liquid from the throat or sputum of the patient is taken and sent for examination in a pathological laboratory.
Question 19: Describe AIDS.
Answer: AIDS stands for Acquired ImmunoDeficiency Syndrome. This disease is caused by a deadly virus known as HIV (Human Immunodeficiency Virus). In this disease, the patient suffers from various types of diseases due to weakening of his/her natural immunity of the body. AIDS cannot be diagnosed or confirmed without proper tests in medical laboratories. ELISA test is basically used for its proper diagnosis. Although the symptoms of AIDS may differ from person to person.
Question 20: When was HIV first reported?
Answer: The fatal disease HIV was first reported in an African species of monkeys. According to the National AIDS Control Program and UNAIDS, about 80 – 85% HIV infections occur in India due to unsafe sexual contact between persons.
Question 21: What are the key points to remember if we come in contact with HIV patients?
Answer: Given below are the key points to remember if we come in contact with HIV patients:
1. AIDS does not spread through touching or coming in direct contact with HIV infected patients or sharing the food with them, or even by nursing such patients.
2. Everyone should maintain a normal behaviour with HIV infected patients and not discard them for their incurable ailment.
Question 22: How is Rabies caused? What are its symptoms?
Answer: Rabies is a fatal viral disease that occurs when an infected dog, monkey or cat bites a human being. The virus enters the human brain through the nerves.
Some of the symptoms of rabies include:
1. Fever for 2 – 12 weeks
2. Exaggerations in behaviour
2. Hydrophobia
When the victim becomes hydrophobic, he/she exhibits extreme fear for water. The fatality of this disease can be prevented by vaccination on time just before the onset of symptoms. Symptoms usually start appearing within 90 – 175 days of the animal bite.
Question 23: Define non-infectious diseases. Give examples.
Answer: There are some diseases which do not occur through infections and direct body contacts are known as non-infectious diseases. Such diseases may arise in the human body
itself due to metabolic or genetic reasons. Some examples include:
1. Cancer
2. Diabetes
3. Hypertension
4. Heart Diseases
Question 24: Explain about Cancer. How is it caused?
Answer: Cancer: Cancer is the abnormal or uncontrolled growth of deadly cells in the human body. A group or lump of cancerous cells are known as a malignant tumor. It can occur in any part of the body such as throat, lungs, mouth, breast, tongue, stomach, uterus, skin and blood tissues, etc.
Some of the possible reasons of cancer are listed below:
1. Consumption of tobacco such as pan masala or gutkha.
2. Heavy smoking.
3. Drinking alcohol.
4. Lack of fiber content such as fresh fruits and leafy vegetables in the diet.
5. Excessive consumption of junk food such as pizza, cola, burger, etc.
6. Genetic reasons in rare circumstances.
Question 25: What are the symptoms of Cancer?
Answer: Some of the summon symptoms of Cancer are:
1. Chronic cough, harsh tonal quality or pitch, difficulty in swallowing food.
2. Scar and inflammation of certain body parts which do not heal quickly.
3. Breast lumps or soreness in breast area.
4. Sudden and unexplained weight loss.
Question 26: Describe Diabetes. What are the symptoms and reasons for this disease?
Answer: Diabetes is a disorder in which the glucose level of the body cannot be controlled due to low secretion of insulin by the pancreas. The hormone insulin is produced in the pancreas as it controls the level of sugar glucose in blood.
Symptoms: Some of the symptoms of this disease include:
1. Unexplained weight loss
2. Increased obesity
3. Frequent urination at night
4. Feeling thirsty often
5. Weakness due to giddiness
Reasons for diabetes: Some of the possible reasons for diabetes are:
1. Obesity
2. Genetic reasons
3. Lack of physical activity
4. Mental stress
Question 27: How does vaccination help in prevention of diseases?
Answer: Vaccines help in preventing diseases which are either dangerous or even deadly. Taking timely vaccinations greatly reduces the risk of any possible infection as it works with the body ’s natural defenses to safely develop an immunity towards a deadly disease.
Question 28: Explain Heart diseases.
Answer: Human heart does not function efficiently when there is decreased oxygen and blood supply and supply of nutrients to the heart muscles. Many a time, heart diseases are caused due to excessive mental stress and in extreme circumstances might cause a heart attack. If a person suffers a cardiac arrest then he/she should be rushed to the doctor immediately and given the necessary treatment.
Question 29: What are the symptoms and reasons for heart attack?
Answer: Symptoms of heart attack: Some of the symptoms of heart attack are listed below:
1. Severe chest pain
2. Acute pain in shoulder blades, neck and arms
3. Cramps and needle-like sensation on the palm of both hands
4. Uneasiness
5. Difficulty in breathing
6. Tremors or shivers across the body
7. Weakness and dizziness
8. Sweating
Reasons for heart attack: Heart attack is caused due to the following reasons:
1. Smoking
2. Alcohol addition
3. Diabetes
4. Obesity
5. Hypertension
6. Lack of physical activity
7. Mental stress
8. Anger
9. Anxiety
10. Heredity
Question 30: How can heart diseases be cured?
Answer: Heart diseases can be managed to an extent by following the below listed medical procedures:
1. Angioplasty
2. By-Pass surgery
3. Open heart surgery
4. Heart transplant
5. Installation of stents
6. Installation of pacemaker
Question 31: Define generic medicines.
Answer: Generic medicines are commonly known as general medicine which are manufactured and distributed without any patent. Such medicines are said to be at par in quality with quality or branded medicines. Usually the production cost of such medicines is comparatively low due to less expenses incurred on research and development as their formula is readily available to manufacture the necessary medicines.
Question 32: What are the causes of lifestyle disorders?
Answer: Lifestyle refers to the daily routine and the type of food consumed by people. In the current generation, lifestyle disorders are caused due to the fact that most people have various bad habits such as staying in bed till late morning and sleeping late at night, frequent changes in meal timings, lack of physical activity, consumption of junk food, etc. Due to all these reasons, such people are frequently falling sick and their body is unable to cope with the changes in their daily lives.
We hope that the above mentioned solutions of “MSBSHSE Class 8 Science Chapter 2 Health and Diseases
” will help students build a strong foundation of the different concepts mentioned in the chapter.