Dear students, prepare for biology class 9th chapter 8 long questions. These important long questions are carefully added to get you best preparation for your 9th class biology ch. 8 exams.
Our database contains a total of 0 questions for biology Short Questions. You’ll prepare using this huge databank.
Define the macronutrients and micronutrients.Explain mineral requirments of planet in detail?
How organic and in-organic fertilizers are important in agriculture?
Ans. Fertilizers "The addition of certain materials to soil sometimes results in plant growth with desirable characteristics (e.g. more fruit, faster growth, more attractive flowers). Such materials are named as fertilizers." Classification of fertilizers Fertilizers are broadly classified as; (i) Inorganic fertilizers (ii) Organic fertilizers Inorganic Fertilizers "Naturally occurring materials which are not chemically modified are called inorganic fertilizers." Example Naturally occurring inorganic fertilizers include; (i) Rock phosphate (ii) Elemental sulphur (iii)Gypsum Nitrogen Fertilizers: If nitrogen is the main element of fertilizers, they are called nitrogen fertilizers. Importance of Inorganic Fertilizers • Mostly inorganic fertilizers dissolve readily in water and are immediately available to plant for uptake. • These fertilizers efficiently supply the required nutrients for plant growth. Organic Fertilizers "Materials which are more complex chemical substances that take time to be broken down into forms usable by plants are called organic fertilizers." Example: Manure and compost Origin Organic fertilizers are derived from either plant or animal materials containing one or more essential elements. Importance of Organic Fertilizer • Organic fertilizers have less salts so their larger amount can be applied without injury t( plant roots. • They can also increase soil drainage, aeration, water holding capacity. • They can increase ability of soil to hold nutrients.
Describe the sources, energy values and functions of carbohydrates, proteins and fats in detail?
Ans. Carbohydrates Carbohydrates are the basic source of energy for all animals. (i) Sources Plants synthesize carbohydrates during photosynthesis. Animals get carbohydrates from their environment. Humans get carbohydrates from food like bread, pastas, beans, potatoes, bran, rice and cereals. (ii) Energy value About half to 2/3 of total calories, every animal consumes daily are from carbohydrates. Carbohydrates contain 04 kilocalories per gram. (iii)Functions Carbohydrates is common source of energy. E.g. glucose. (iv )Other useful carbohydrates Other useful carbohydrates are maltose, lactose, sucrose and starch. Proteins (1) Introduction "Proteins are composed of amino acids." (i) Sources Meat, eggs, grains, legumes and dairy products such as milk and cheese are dietary sources of proteins. Energy level One gram of proteins contains 04 kilocalories of energy. Functions (i) Proteins can also be used for gaining energy. (ii) Proteins are essential components of muscles, ligaments and tendons. (iii)They are also major components of cytoplasm, membranes and organelles. (iv )Proteins play role as "enzymes". (v) Proteins are used for growth Lipids (Lahore board 2012 G H) (short questions) "Lipids present in food are composed of fatty acids bonded to glycerol." Types of fatty acids: Fatty acids of lipids are; (i) Saturated fatty acids. (ii) Un-saturated fatty acids. (i) Saturated fatty acids Saturated fatty acids have all of their carb (i) Unsaturated fatty acids (ii) Un-saturated fatty acids have some of their carbon atoms double-bonded in place of hydrogen atoms. (iii) Lipids containing saturated fatty acids are solid at room temperature. (iv) Lipids containing un-saturated fatty acids are liquid at room temperature. Example: (i) Butter contains 70% saturated and 30% unsaturated fatty acids. (ii) Sunflower oil contains 75% unsaturated and 25% saturated fatty acids. (iii)Sources Milk, butter, cheese, eggs, mutton, fish, mustard seeds, coconut and dry fruit etc. (iv )Energy Level One gram of lipids contains 09 kilocalories of energy. (v) Functions (i) Lipids are also useful energy source. (ii) It is used to form membranes, sheaths of neurons and hormones.
Describe the role of calcium and iron in our diet.
Ans. Calcium (i) Role of calcium (i) Calcium is essential for the development and maintenance of bones and teeth. (ii) It is also needed for maintaining cell membranes and connective tissues. (iii) It is used for activation of several enzymes. (iv) Calcium also aids in blood clotting. (v) Good calcium nutrition, along with low salt and high potassium intake, prevents from hypertension and kidney stones. (ii) Sources:- Humans get calcium from milk, cheese, egg Yolk, beans, nuts, cabbage etc. Effects of Calcium Deficiency (i) Spontaneous discharge of nerves impulses which may result in tetany. (ii) Bones also become soft, blood clots slowly and wounds heal slowly. Iron: (i) Role of Iron (Lahore board 2012 G 11) (i) Iron plays a major role in oxygen transport and storage. (ii) It is a component of hemoglobin in red blood cells and myoglobin in muscle cells. (iii) Cellular energy production also requires iron. It acts as cofactor for many enzymes of cellular respiration. (iv) Iron also supports immune function. (ii) Sources: Humans get iron from red meat, egg yolk, whole wheat, fish, spinach, mustard etc. (iii) Effects of Iron deficiency Iron deficiency causes anemia.
Define vitamins. Describe different types of Vitamins.
Ans. Definition Vitamins are chemical compounds that are required in low amounts but are essential for normal growth and metabolism. Types Vitamins may be divided into two groups: Fat-soluble Vitamins: These are Vitamins A, D, E and K. Fat-soluble vitamins are much less excreted from the body as compared to water-soluble vitamins. This means that levels of water-soluble vitamins in the body can decrease more quickly, leading to vitamin deficiency. (i) Water soluble Vitamins These are vitamins B and C. Cooking or heating destroys the water soluble vitamins more readily than the fat-soluble vitamins. Types (i) Vitamin A (i) Identification Vitamin A was the first fat soluble vitamin identified in 1913. (ii) Functions (i) Formation of Rhodopsin Vitamin A combines with a protein called opsin to form rhodopsin in the rod cells of the retina of eye. Sometimes, there is lack of vitamin, so there is less rhodopsin. It makes difficult to see in dim light. (ii) Cell Differentiation It is involved in normal cell differentiation. The process through which embryonic cells transform into mature cells with highly specific functions is called differentiation. (iii) Bone Growth Vitamin A supports bone growth. (iv )Immune Function It is essential for immune function. Deficiency of Vitamin A causes decreased resistance to infections. (v) Sources Humans get Vitamin A from leafy vegetables (Spinach, carrots), yellow/orange fruits (mango), liver, fish, egg, milk, butter, etc. Effects of Vitamin A Deficiency (i) Blindness Deficiency of Vitamin A causes blindness in children worldwide. One of the symptoms of Vitamin-A deficiency is night blindness. It is a temporary condition. But if left untreated it can cause permanent blindness. (ii) Rough Hair and Skin Hair follicles are plugged with keratin due to deficiency of Vitamin A. It makes the hair bumpy and rough. It gives dry texture to skin. (ii) Vitamin C (Ascorbic Acid) (i) Identification It is a water soluble Vitamin. (ii) Functions (I) Participation in Reactions Vitamin C participates in many reactions. (ii) Formation of a Fibrous Protein Collagen Vitamin C is needed to form collagen (a fibrous protein). Collagen gives strength to connective tissues. Collagen is also needed for the healing of wounds. (iii)White blood Cells White blood cells need Vitamin C. It enables the immune system to function properly. (iv) Sources We get Vitamin C from citrus fruits e.g, oranges, Lemons, and grape fruit), Leafy green Vegetables, beef liver etc. Effects of Vitamin C Deficiency (i) Scurvy (Lahore board 2011 G IT) Its deficiency causes connective tissue changes throughout the body. This disease known as scurvy. In this condition, synthesized collagen is too unstable. Symptoms of scurvy are muscle and joint pain, swollen and bleeding gums, slow wounds healing and dry skin. Vitamin D (i) Identification It is fat soluble Vitamin. (ii) Functions (i) Absorption of Minerals from Intestine It helps to regulate levels of Calcium and Phosphorous in blood. It increases absorption of these minerals from the intestine. It also increases their deposition in bones. (ii) Sources (Lahore board 2012 G I) Vitamin D is mainly found in fish liver oil, milk, ghee and butter etc. It is also synthesized by the skin when ultraviolet (UV) radiations from the sun is used to convert a compound into vitamin D. Effects of Vitamin D Deficiency (i) Rickets: Deficiency of vitamin D affects bones. In children, vitamin D deficiency leads to rickets, a condition in which bones weaken and bow under pressure. Osteomalacia: In adults, vitamin D deficiency
Why are water and dietary fibers considerd important in our diet?
Ans. Effects of water and dietary fibres Strictly speaking water and dietary fibres are not considered as nutrients, but they do play important role in life. Introduction Water Approximately 60% of the adult human body is composed of water. It is considered important due to following facts. (I) Aqueous environment: Nearly all of the life sustaining chemical reactions require an aqueous (watery) environment. (ii) Absorption & Elimination of substances Water functions as the environment in which water soluble food stuff is absorbed in the intestines and waste products are eliminated in urine. (iii)Maintenance of body temperature Water maintains the body temperature through evaporation as in sweating. (iv) Cardiovascular problems Severe dehydration causes cardio-vascular problems. (v) Requirement An Adult requires two litres of water on average per day from different sources i.e. natural water, milk, juicy fruits and vegetables. Dietary fibres (Lahore board 2012 G H) Definition Dietary fibre (also known as roughage) is the part of the human food that is indigestible. Source It is found only in plant foods and it moves undigested through the stomach and small intestine and into the colon. Types of dietary fibres There are two types of dietary fibres. (i) Insoluble fibre (ii) Soluble fibre (I) Insoluble fibres These travel through the small intestine quickly. Sources Wheat bran, cereals and skin of many fruits and vegetables consist of insoluble fibres. (ii) Soluble fibres These fibres break down as these pass through the digestive track. Sources Oat, beans, barley and many fruits and vegetables: Important functions of fibres (i) Prevents from constipation Fibre prevents and relieves constipation by stimulating the contraction of intestinal muscles, (ii) Lowering blood cholesterol Soluble fibre helps in lowering the blood cholesterol. (iii) Lowering blood sugar level Soluble fibre helps in lowering blood sugar levels. (iv) Exposure to carcinogens Insoluble fibre speeds tip the movement of carcinogens (cancer causing agents) from intestine. (v) Use of fibre supplements Fibre supplements (such as ispaghol husk) should be used only with a physician's recommendations. Taken properly, these supplements may help in preventing constipation and in lowering cholesterol levels
Describe the effects of malnutrition.
Ans. Effects of Malnutrition (i) Starvation: Starvation is a severe reduction in nutrient and energy intake. In humans, prolonged starvation causes permanent organ damage. It may result in death. (ii) Heart Diseases It is one of the causes of malnutrition. Heart problems occur in those people who take unbalanced diet. Fatty foods increase blood cholesterol level. It obstructs the blood vessels leading to heart diseases. (iii)Constipation People do not schedule their meals. This irregularity cause many health problems like constipation. (iv) Obesity "Obesity means becoming over-weight and it may also be due to malnutrition." People who take food that contains energy more than their requirement and do very little physical work can become obese. Obesity is known as mother-disease and may lead to heart problems, hypertension, diabetes etc. (v) The World Health Organization (WHO) estimates that, within the next few years, diseases due to malnutrition will become the principal global causes of mortality. (vi) According to the Food and Agriculture Organization of the United Nations, more than 25,000 people die of starvation every day. On average, every five seconds a child dies from starvation.
Briefly give the signs and symptoms, causes, treatments and preventions of Diarrhoea, constipation and ulcer?
Ans. Diarrhoea Introduction: It is a condition in which the sufferer has frequent watery, loose bowel movements. Sign and symptoms This condition may be accompanied by; Abdominal pain Nausea Vomiting Causes: It occurs when required water is not absorbed in blood from colon. The main cause of diarrhoea include; Lack of adequate safe water Virus and bacteria may cause it. Treatment In malnourished individuals, diarrhoea can lead to severe dehydration and can become life threatening. Treatment for diarrhoea involves consuming adequate amounts of water to replace loss, preferably mixed with essential salts and some amount of nutrients. Antibiotics may be required if diarrhoea is due to bacterial infection. Prevention: Take clean water and essential salts. Eat regularly. Take hygienic measures. Constipation: Constipation is a condition where a person experiences hard faces that are difficult to eliminate. Cruses: The main causes of constipation are: (it Hardening of faces due to excessive absorption of water through colon. (1) Insufficient intake of dietary fiber. Iii) Dehydration ,iv) Use of medicine (e.g. those containing iron, calcium and aluminum) ',.v) Tumors in rectum or anus. Treatment: Treatment of constipation is; (I) with a change in dietary and exercise habits. (ii) Laxative (e.g. paraffin) may be used in some cases. Prevention: (i) Constipation is easier to prevent than treat. (ii) Take required quantities of water and dietary fibers. Ulcer Definition Ulcer (peptic ulcer) is a sore in gut lining. Types (1) Ulcer of stomach is called "gastric ulcer". (ii) Ulcer of duodenum is called "duodenal ulcer" (iii)Ulcer of esophagus is called "esophageal Ulcer." Causes (i) Breakdown of tissue by acidic gastric juice. (ii) Infection. (iii) Long term use of anti-inflammatory medicine (e.g. aspirin). (iv) Smoking. (v) Drinking coffee, colas (vi) Eating spicy food. Sign and symptoms (i) Abdominal burning after meals. (ii) Abdominal pain. (iii) Rush of saliva after an episode of regurgitation. (iv) Nausea (v) Loss of appetite. (v i)Loss of weight (vi) Treatment: Treatment of ulcer is with medicine, containing (alkaline composition). Prevention: Avoid (i) Spicy food ii) Smoking
Q no: 5 (A) Define and<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15863228595365946027766"> .</gwmw> Explain mineral requirements of plants in detail.
Role in plant life
Sulphur Component of proteins, vitamins and enzymes
the enzymes that reduces nitrates to important in building amino acids
Phosphorus Component of ATP, nucleic acids and coenzymes, necessary for seed germination photosynthesis, protein formation
Potassium Regulates the opening and closing of the, reduces water from the leaves
Calcium Activates enzymes, is a structural component of cell wall, water movement in cells.
Role in life
Iron Necessary for photosynthesis, activatesmany enzymes
Boron Important in sugar transport, cell, division and synthesizing certain enzymes
Copper Component of several enzymes
Manganese Involved in
enzymesactivity for photosynthesis, respiration, and nitrogen metabolism
Zinc Required in a large number of enzymes
Chlorine involved in osmosis of water
Nickel Required in a nitrogen metabolism
Q no<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15863230322176801169593">:</gwmw>5 (B) What is the role for nitrogen and magnesium of plant growth?
A plants get nitrogen in the form of
nitrates nitrogen is a major component of protiens, hormones, chlorophyll, vitaminsand enzymes essential for plant life. Nitrogen metabolism is a major factor in stem and leaf growth Too much nitrogencan delay flowering and fruiting deficiencies of nitrogen can reducdyields cause yellowing of the leaves and stunt growth.
Magnesium is a structural component of chlorophyll. It is also necessary for the functioning of plant enzymes to produce carbohydrates, sugar and fats
. It is use for fruit and nut formation and essential for gerneration of seed. Deficiency of magnesiumcauses yellowing and witting of leaves.
Q no<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15863248003660257984663">:</gwmw>6 (A) Describe the role of calciumand in our diet.
A Calcium is essential for the development and maintenance of bones and
teeth it is also needed for maintaining cell membranes and connective tissues and for the activation of several enzymes, Calcium also acids in blood clotting. Humans get calcium from milke, Cheese, egg yolk, beans, nuts, cabbage etc. Deficiency of calcium causes spontaneous discharge of nerve impulses which may result in tetanybones also become soft blood clots slowly and heat slowly
Iron plays a majorrole in oxygen transport and storage. It is a component of hemoglobin in red blood cells and myoglobin in muscle cells.
Celluar energy production also requiration. Iron also supports immune function. Humans get iron from red meat egg yolk, whole wheat, fish, spinach, mustard etcIts dificiency is the most common nutrient dificiencyworldwide iron dificencycauses anemia.
Q no: 6 (B) Write a note on <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15863255769620628094662">digestive</gwmw> of food in stomach.
A stomach is a dilated of alimentary carol.
it is J-shaped, located in leftof abdomen. Just beneath diaphragm. Stomach has two main portions, cardiac portion of stomach is present immediatly after osophagusand pyloric portion is located beneath cardiac portion. stomachhas two sphincters (openingswhich are guarded by muscles ) Cardiac sphincter is between stomac and osophoguswhile pyloric sphincter is between stomac and smallintestine. Bolus enters stomachfrom osophogusthrough cardiac sphincter. When food enters stomac , the gastricglands found in the stomachwall are stimulated to secrete gastric Juice Gastzic juice is composed chiefly of mucous, hydrochloric acid, aic a protein-digesting enzymes pepsinogenHydeochloric acid converts the inactive enzymes pepsinoyen into its activ form form i.e pepsin .Hcl also kills microganisms present in food ,pepsin partially digests the protein portion of food ( bulk of mutton into polypeptides and shorter peptide chains in stomach , food is further broken apart through a process of churning. The walls of Stomach contract and relax and these movements help in thorough mixing of gastricjuice and food. The churning action also produces heat which helps to melt the lipid content of food.
The starch in our bite of bread and the protein in mutton have been partially digested and the food has been converted digested aid the food has teen converted to a soup-like mixture called chyme.
after it the pyloric sphincter allows a little mass of chyme to enter duodenum
Q no: 7 (A) What are water and dietary <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15863284294956540575933">fibres</gwmw>considered <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15863284430814909434033">important</gwmw> of our diet.
A strictly speaking, water and dietary fiber are not considered as nutrients, but they do play
important role of life. Fibre prevents and relives constipationby stimulating the contraction of intestinal muscles Avoiding constipation, reduce the risk of many other disease soluble fibers help in lowing blood sholesterand sugar levels insoluble fibrespeed up the movement of carcinogens ( cance causing agent) From intestine
Approximately 60% of the adult human body is composed of water. Nearly are life
sustaningchemical reactions required an aqueous (water) environmentwater also functions as the environmentin which water- soluble food stuff is absorbed in the intestines and the waste products are eliminated in using anther essential role of water is to maintain body temperature through evaporation, as in sweetine, severe dehydration may result in cardiovasclusproblems. The estimated water requirementof and everageadult is two liters per day imported Sources of daily water intake are natural water, milk ,Juicy fruits and vegitable.
fibre ( also known as roughage') is the past of human food that is indigestible. It is found only in plant food and moves undigested through stomac and small intestine and into colon. The insoluble dietary fibretravel quickly Through small intestines . Its sources are wheat bran, cetealsand skins of many fruits and vegitables. The soluble dietary fibrebreaks down as it passes though alimentary canal . itssources are oats, beans, barley, and many fruits and vegetables.
What is<gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15863306659421596735092">ulcer</gwmw>? <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15863306777397486937921">Decribe</gwmw> Causes and symptoms?<div><br></div>
( peptic ulcer) is a sore in the inner wall of gut ( in osophagus, duodenum or stomach in ulcer, the acidic gestric juice gradually break down the tissue of the inner wall Ulcer of stomach is called gastric ulcer. The causes of ulcer include excess, acid, infection long term use of anti inflammatory medicines (including aspirn), smoking drinking coffee, colas and eating spicy food.
The signs and symptoms of
ulcer include abdominal burning after meals or at midnight severe ulcer, many may cause abdominal pain, rush of saliva after an episode of regurgitation, nausea, loss of appetiteand weight loss ulcer is treated with medicines, which neutralize the acidic affects of gastric juice, spicy, acidic foods and smoking should be avoided as preventive measures
What are roles of nitrogen and magnesium in plants ?
Role of nitrogen : Plants get nitrogen is a major component of proteins , hormones , chlorophyll ,vitamins and enzymes essential for plant life . Nitrogen metabolism is a major factor in stem and leaf growth . Too much nitrogen can delay flowering and fruiting
Define fertilizers. Give its importance and environmental hazards
Fertilizer : As humans cultivated plants , it was learned that addition of certain materials to soil sometimes resulted in plants with desirable , such materials were name as fertilizers
Example : Fruit , faster growth , more attractive flowers
-Types of fertilizers :
Fertilizers broadly classified as
1: Organic 2: Inorganic
further the organic and inorganic fertilizers may be natural or artificial
Naturally occurring inorganic fertilizers :
Naturally occurring inorganic fertilizers include
1: Rock phosphate
2: Elemental sulfer
These are not chemically modified
If nitrogen is the main element , they are called nitrogen fertilizers
Most inorganic fertilizers dissolves readily in water and are immediately available to plants for uptake
Naturally occurring inorganic fertilizers :
Organic fertilizers are derived from plant and animal materials . They are more complex and take time to be broken down into forms usable by plants . Manure and compost are used as organic fertilizers . They can also increase soil drainage , aeration and the ability of the soil to hold nutrients
The distinction between the organic and inorganic fertilizers is not always clear cut . Urea for example , is an organic compound . but chemically synthesized urea is generally grouped with inorganic fertilizers
Explain different components of human food
The nutritional requirements of human and other animals are relatively complex as compared to plants . Like other animals the nutrients used by human include
3: Nucleic acids
The organic compounds which are composed of carbon , hydrogen , oxygen
Composition : Carbohydrates are the basic source of energy for all animals . After half to 2/3 of the total calories every animal consumes daily are from carbohydrates . Glucose is the most often used carbohydrates for energy . Other useful carbohydrates are maltose , lactose , sucrose and starch . Carbohydrates contain 04 kilo calories per gram
Energy : Carbohydrates contain 04 kilicalories per gram
Sources of carbohydrates : Humans gets carbohydrates from the food like bread , pastas , beans , potatoes , bran , rice , cereals
Carbohydrates are the most common source of energy . Proteins and lipids are vital building components for body but they can also be used for energy
2: Lipids : The lipids are the hydrophobic compounds and basic part of the cell membrane . The lipids present in food are composed of fatty acids bonded to glycerol
Example : Fats , oil and waxes
Types of fatty acid :
1: Unsaturated fatty acids 2 : Saturated fatty acids
1: Unsaturated fatty acids : Unsaturated fatty acids have some of their carbon atoms double bonded in place of a hydrogen atom and are liquids at room temperature
Example : sunflower oils contain nearly 75%unsaturated fatty acids these are good for health
2 : Saturated fatty acids : Saturated fatty acids have all their carbon atoms bounded to hydrogen atoms and are solid at room temperature and are called fat
Example : Butter contain nearly 70% saturated and 30% unsaturated fatty because saturated fatty acids can increase a person's cholesterol level may eventually results in the clogging of arteries and ultimately ,heart disease
Importance : Lipids are used to form membranes , the sheaths surrounding neurons and certain hormones . Lipids are also extremely useful energy sources
Sources of lipids :Important sources of lipids include milk , butter , cheese eggs , mutton , fish , mustard seeds , coconut and dry fruits etc
What are the effects of water and dietary fibre ?
2: Soluble fiber : The soluble dietary breaks down as it passes through alimentary canal Sources: Its sources are oats ,beans ,barely and many fruits and vegetables
What is balanced diet ? Give its relation with age , gender and activity
Balanced diet : The one which contains all the essentials nutrients in correct proportion of the normal growth and development of body
Let thy food be the medicine : Hippocrates
Human require various types of nutrients in order to keep then healthy and fit
A balance diet is related to one's age , gender and activity . It should include different types of nutrients and should be according to the energy requirement . The following chart shows some of the common foods , taken in Pakistan , and the percentage of carbohydrates , lipids and proteins in each of them
Define malnutrition . What are the effects of malnutrition ?
Malnutrition : Problems related to nutrition are grouped as malnutrition . It often refers to under nutrition resulting from inadequate consumption , poor absorption , or excessive loss of nutrients . Malnutrition also includes over-nutrition resulting from overeating or excessive intake of specific nutrients
Most commonly , malnourished people dont have enough calories in their diet or eat a diet that lack protein , vitamins or trace minerals
Explain forms of malnutrition ?
Common forms of malnutrition include :
1: Protein energy malnutrition (PEM)
2:Minerlas deficiency disease (MDD)
3: Over intake of nutrients (OIN)
What are effects of malnutrition ?
An extended period of malnutrition can lead to problem like
Describe the major causes of famine
The main cause of malnutrition is famine
Famine : Famine means the lack of enough food to feed all people living in an area . The most terrible famine of the twentieth century are the Ethiopian famine (1983-85) and the north Korean famine (1990's)
Famine also may be due to the problems created by humans e.g wars and wrong economic polices