9th Class Chapter 8 Biology Long Questions

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 malnutrition.Describe its important and its forms.

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.

Describe the function of lever.

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

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.

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

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.

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.

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>

Ulcer:

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

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

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

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

Explain forms of malnutrition ?

Common forms of malnutrition include :

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