Biology For Class IX - Chapter No.8 - NUTRITION - Review Questions From Text Book

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CHAPTER 8
NUTRITION
Review Questions From Text Book

1. Encircle the correct answer:
(i) Select the mismatched
(a) Protein → Amino acid
(b) Carbohydrate → Glucose
(c) Fats → Starch ✔
(d) Nucleic acid → Nucleotide

(ii) Deficiency of vitamin-k cause
(a) Rickets
(b) Anemia ✔
(c) Scurvy
(d) Beriberi

(iii) Period of rapid growth and development called:
(a) Childhood
(b) Adult hood
(c) Adolescence
(d) Both “a” and “c” ✔

(iv) Deficiency of dietary protein, causes an imbalance in the gastrointestinal system:
(a) Marasmus
(b) Edema
(c) Diarrhea
(d) Kwashiorkor ✔

(v) An animal that migrates great distances would obtain the greatest benefit from storing its energy as:
(a) Fats ✔
(b) Carbohydrates
(c) Protein
(d) Minerals

(vi) Which of the following vitamins is correctly associated with its use?
(a) Vitamin K → Production of white blood cells
(b) Vitamin C → Curing rickets
(c) Vitamin E → Protection of skin from cancer
(d) Vitamin A → Incorporated into the visual pigment of the eye ✔

(vii) Which of the following statements describes pepsin?
(a) It is manufactured by the pancreas.
b) It helps stabilize fat-water emulsions.
(c) It splits maltose into monosaccharides.
(d) It begins the hydrolysis of proteins in the stomach. ✔

(viii) Which of the following is true about bile salts?
(a) They are enzymes
(b) They are manufactured by the pancreas
(c) They emulsify fats in the duodenum ✔
(d) They increase the efficiency of pepsin action.

(ix) In human digestive system trachea and oesophagus both connect to the:
(a) Large intestine
(b) Stomach
(c) Pharynx ✔
(d) Rectum

(x) All are sources of calcium except:
(a) Red meat ✔
(b) Green leafy vegetables
(c) Broccoli
(d) Nuts

2. Fill in the blanks:
(i) Sea food is an excellent source of protein because it's usually low in fats.
(ii) Iron deficiency is associated with decreased cognitive abilities and resistance to diseases.
(iii) Wave of rhythmic movements of muscle contraction and relaxation called peristalsis.
(iv) Liquid secreted by the pancreas, which contains a variety of enzymes.
(v) Living organisms which derive their food from dead and decaying organic materials called saprotrophs or saprotrophic organisms.
(vi) Nutrients that are needed in the highest concentration called macronutrients.
(vii) Fertilizers are substances containing chemical elements such as manure or mixture of nitrates.
(viii) High solubility of fertilizers also degrades ecosystem through eutrophication.
(ix) Carbohydrates which digested quickly are called starch or simple carbohydrates.
(x) Each gram fat supplies the body with about 9 calories.

3. Define the following terms:
(i) Vitamins
(ii) Malnutrition
(iii) Goiter
(iv) Anemia
(v) Constipation
(vi) Obesity
(vii) Starvation
(viii) Ingestion
(ix) Chyme
(x) Ulcer
Ans: (i) VITAMINS:
A vitamin is an organic molecule (or related set of molecules), an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. They are for maintaining normal health and development. Lack of vitamins can cause several diseases.
They are divided into two types:
Fat Soluble Vitamins are vitaimns A, D, E and K)
Water Soluble Vitamins are vitamins B and C.
Source Of Vitamins:
Milk, Fruits and Vegetables.

(ii) MALNUTRITION:
Problems related to nutrition are grouped as malnutrition. The malnutrition is a condition that occurs when a body does not get enough nutrients. Malnutrition results from a poor diet or a lack of food. It happens when the intake of nutrients or energy is too high, too low, or poorly balanced. Consuming less than 2100 calories a day, one is considered to be under-nourished and suffering from hunger.
There are two types of malnutrition:

• Chronic malnutrition
• Acute malnutrition

OR

Malnutrition is a serious condition that happens when the diet does not contain the right amount of nutrients. It means "poor nutrition" and can refer to undernutrition – not getting enough nutrients.
There are two types of malnutrition

• Chronic malnutrition
• Acute malnutrition

(iii) GOITER:
Goiter is a condition in which thyroid gland becomes enlarged and it results in swelling in neck. Goiter is caused by an insufficient amount of “Iodine” in diet. Iodine is used by thyroid gland to produce hormones that control the body's normal functioning and growth.

OR

A goiter is an enlargement of the thyroid gland which results in the swelling of neck. Goiter is caused by an insufficient amount of “Iodine” in diet. Iodine is used by thyroid gland to produce hormones that control the body's normal functioning and growth.

(iv) ANEMIA:
The term anemia literally means “a lack of blood”. The condition is caused when number of red blood cells reduced to a level lower than normal. Haemoglobin molecule contains four atom of iron. If body fails to receive sufficient amount of iron, an adequate number of haemoglobin will not be formed. So, there are not enough functioning red blood cells. A person becomes weak and there is shortage of oxygen supply to body's cells.

OR

The term anemia literally means “a lack of blood”. Anemia is a condition in which the body lacks enough healthy red blood cells to carry adequate oxygen to the body's tissues. Having anemia can make one feel tired and weak. There are many forms of anemia, each with its own cause. Anemia can be temporary or long term, and it can range from mild to severe.

(v) CONSTIPATION:
Constipation is a condition, where a person experiences hard faeces that are difficult to eliminate. The main causes of constipation are hardening of faeces due to excessive absorption of water through colon, insufficient intake of dietary fibre, dehydration, use of medicine (e.g. those containing iron, calcium and aluminum) and tumors in rectum or anus.

(vi) OBESITY:
It is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health. Obesity is most commonly caused by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. Obesity is known as mother disease and may lead to heart problems, hypertension, diabetes etc.

OR

Obesity is defined as abnormal or excessive fat accumulation that presents a risk to health. Obesity is most commonly caused by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. Obesity is known as mother disease and may lead to heart problems, hypertension, diabetes etc.

(vii) STARVATION:
It is a severe deficiency in caloric energy intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death.

(viii) INGESTION:
Food enters the digestive system through the mouth. This process is called ingestion. Once in the mouth, food is chewed to form a ball of food called a bolus. This passes down the oesophagus and into the stomach.

(ix) CHYME:
In stomach food is partially digested and further broken apart through a churning process. The churning action also produces heat which helps to melt the lipid contents of the food. By the time food is ready to leave the stomach, it has been processed into a thick paste like liquid called chyme.
The pylorus keeps chyme in the stomach until it reaches the right consistency to pass into the small intestine. Chyme is then squirted down into the small intestine, where digestion of food continues.

OR

Chyme, is a thick semifluid mass of partially digested food and digestive secretions that is formed in the stomach and intestine during digestion. In the stomach, gastric juice is formed by the gastric glands, these secretions include the enzyme pepsin, which breaks down proteins, and hydrochloric acid.
Food is further broken apart through a process called churning. The walls of stomach contract and relax and these movements help in mixing of the gastric juice and food. The churning action also produces heat which helps to melt the lipid contents of the food.

(x) ULCER:
It is a sore in gut lining and can be different organs such as; ulcer of stomach is called “gastric ulcer”, Ulcer of duodenum is called “duodenal ulcer”, ulcer of oesophagus is called “esophageal ulcer” and breakdown of tissues by acidic gastric juice. It can be due to the long term use of anti-inflammatory medicine (e.g. aspirin), smoking, drinking coffee, colas and eating spicy food.

OR

Ulcer is an open sore on an external or internal surface of the body, caused by a break in the skin or mucous membrane which fails to heal. Ulcers range from small, painful sores in the mouth to bedsores and serious lesions of the stomach or intestine. It can be due to the long term use of anti-inflammatory medicine (e.g. aspirin), smoking, drinking coffee, colas and eating spicy food.

4. Distinguish between the following in tabulated form.
(i) Fat-soluble vitamins and water soluble vitamins

-	Water soluble vitamins	Fat-soluble vitamins
Vitamins	B, C	A, D, E, K
Site of Absorption	Small intestines	Small intestines
Dietary Intake	Excess intake usually detected and excreted by the kidneys	Excess intake tends to be stored in fat-storage sites
Solubility	Hydrophilic	Hydrophobic
Capitalize	Easily absorbed the blood, travels freely in the bloodstream	Absorbed into the lymphatic system, many require protein carriers to travel in the blood
Body storage	Not generally	Yes
Deficiency	Deficiency symptoms appear relatively quickly	Deficiency symptoms are slow to develop
Toxicity	Low risk	Higher risk
Need for daily consumption	Yes	No

(ii) Marasmus and kwashiorkor

S.No	Kwashiorkor	Marasmus
1.	The deficiency of protein in the body of children upto three years leads to the kwashiorkor.	The deficiency of calories and other nutrition in the children of upto one year leads to Maramus
2.	It occurs due to deficiency of proteins.	It occurs due to deficiency of calories, proteins and other nutrients.
3.	Acute illness, trauma, infections, measles, Sepsis are some of the causes of the kwashiorkor.	Chronic infections, prolonged starvation, recurring infections are some of the significant causes of Marasmus.
4.	Muscles and limbs get thin.	Limbs get thin.
5.	Oedema (when an excess of watery fluid is accumulated in the tissues or cavity of the body) is present.	Oedema is absent.
6.	Subcutaneous fat (harmless fat present under the skin and protect against some pathogens and disease) is present.	Subcutaneous fat is absent
7.	Typical weight loss is observed.	There is severe weight loss
8.	Enlargement in fatty liver cells	No such enlargement is observed
9.	Appetite is prodigious.	Appetite is poor.
10.	Cracky skin appears	Wrinkled and dry skin appears
11.	No prominent ribs	Prominent ribs.
12.	High mortality	Low mortality, until the condition, is severe.

OR

-	Kwashiorkor	Marasmus
Causes	Deficiency of proteins.	Deficiency of both proteins and calories.
Age factor	Between the age of 6 months and 3 years of age.	Between the age of 6 months and 1 year of age.
Oedema	Present.	Absent.
Subcutaneous fat	Present.	Absent.
Weight loss	There is some weight loss.	There is severe weight loss.
Symptoms	The thinning of muscles and limbs.	The thinning of limbs.
Fatty liver cells	There is an enlargement in the fatty liver cells.	There is no enlargement in the fatty liver cells.
Appetite	Voracious feeder	Poor appetite.
The texture of the skin	Flaky paint appearance on the skin.	Dry and wrinkled skin.
Requirement of Nutrition	Adequate amounts of proteins.	Adequate amounts of proteins, carbohydrates and fats.

(iii) Chemical digestion and mechanical digestion

S.No	Mechanical digestion	Chemical digestion
1.	Mechanical digestion refers to the breakdown of food into digestible particles, mainly by teeth.	Chemical digestion refers to the process by which compounds with a high molecular weight in the food are broken down into small substances that can be absorbed by the body.
2.	It occurs from the mouth to the stomach.	It occurs from the mouth to the intestine
3.	A major part of mechanical digestion occurs in the mouth	A major part of chemical digestion occurs in the stomach.
4.	It is driven by teeth.	It is driven by enzymes
5.	It increases the surface area for the ‘enzymatic reactions in the chemical digestion	It enhances the absorption of the nutrients by breaking down them into small molecules.

OR

-	Chemical digestion	Mechanical digestion
Definition	It breaks down the food chemically into the form that can be used by the cells.	It breaks down food into small pieces physically.
Beginning	Begins in mouth when food mixes with saliva	Begins in mouth as food is chewed.
Occurrence	Mouth to the intestine	Mouth to stomach.
Materials involved	Enzymes,bile and acids etc	Teeth, tongue and muscles etc
Main activity	Hydrolysis by enzymes	Chewing and grinding.
Importance	Chemically digestion	Mechanical digestion
Facilitates	absorption of nutrients.	facilitates chemical digestion

(iv) Autotrophic nutrition and Heterotrophic nutrition

S.No	Autotrophic nutrition	Heterotrophic nutrition
1.	Autotrophic nutrition is a mode of nutrition in which an organism prepares its own food with the help of simple inorganic materials like water and carbon dioxide from the surrounding.	Heterotrophic nutrition is a mode of nutrition in which an organism cannot prepare its own food and depend upon other organisms for its food.
2.	For autotrophic nutrition, presence of chlorophyll (green pigment) and sunlight are necessary. Autotrophic nutrition takes place during day time.	No green pigment and sunlight is required for heterotrophic nutrition.
3.	All green plants synthesizing their own food through the biological process are referred to as photosynthesis are examples of autatrophs.	Animals including herbivores, omnivores and carnivores are examples of Heterotrophs.
4.	In the food chain, autotrophs are the primary producers.	Heterotrophs are consumers; they are place at secondary or tertiary level.
5.	Types of autotrophic mode of nutrition include: phototrophic and chemotrophic.	Types of heterotrophic mode of nutrition include: holozoic, saprophytic, parasitic and symbiotic association.
6.	Autotrophs are independent of any organisms.	Heterotrophs rely on other organisms for their food.
7.	Autotrophs are capable of storing sunlight and chemical energy.	Heterotrophs are not capable of storing energy.
8.	Heterotrophs can move from one place to another in search of food.	Autotrophs cannot move from one place to another.
9.	In autotrophs, the process of digestions is absent	Heterotrophs, the process of digestion is required to convert complex molecules into simpler molecules.

OR

BASIS OF COMPARISON	HETEROTROPHIC NUTRITION	AUTOTROPHIC NUTRITION
Description	Autotrophic nutrition is a mode of nutrition in which an organism prepares its own food with the help of simple inorganic materials like water and carbon dioxide from the surrounding.	Heterotrophic nutrition is a mode of nutrition in which an organism cannot prepare its own food and depend upon other organisms for its food.
Requirement	For autotrophic nutrition, presence of chlorophyll (green pigment) and sunlight are necessary. Autotrophic nutrition takes place during day time.	No green pigment and sunlight is required for heterotrophic nutrition.
Examples	All green plants synthesizing their own food through the biological process are referred to as photosynthesis are examples of autotrophs.	Animals including herbivores, omnivores and carnivores are examples of heterotrophs.
In food Chain	Autotrophs are the primary producers.	Heterotrophs are consumers; they are place at secondary or tertiary level.
Mode of nutrition	Include: phototrophic and chemotrophic.	Include: holozoic, saprophytic, parasitic and symbiotic association.
Dependency	Autotrophs are independent of any organisms.	Heterotrophs rely on other organisms for their food.
Storage of Energy	Autotrophs are capable of storing sunlight and chemical energy.	Heterotrophs are not capable of storing energy.
Movement	Heterotrophs can move from one place to another in search of food.	Autotrophs cannot move from one place to another.
Digestion	In autotrophs, the process of digestion is absent.	In Heterotrophs, the process of digestion is required to convert complex molecules into simpler molecules.

(v) Inorganic fertilizers and organic fertilizers
(Note: Inorganic fertilizers are also called Chemical fertilizers and Organic fertilizers are also called natural fertilizers)

S.No	Inorganic Fertilizers	Organic Fertilizers
1.	Inorganic fertilizers are rich equally in three essential nutrients that are needed for crops and always ready for immediate supply of nutrients to plants if situation demands.	Adds natural nutrients to soil increases soil organic matter, improves soil structure and tilth, improves water holding capacity, reduces soil crusting problems, reduces erosion from wind and water, Slow and consistent release of nutrients.
2.	Several Inorganic fertilizers have high acid content. They have the ability to burn the skin. Changes soil fertility.	Have slow release capability; distribution of nutrients in organic fertilizers is not equal.
3.	Immediate supply or fast release	Slow release
4.	Inorganic fertilizers are manufactured from synthetic material.	Organic fertilizers are made from materials derived from living things
5.	Artificially prepared	Prepared naturally
6.	Inorganic fertilizer has an equal distribution of three essential nutrients: phosphorous, itrogen, potassium.	Have unequal distribution of essential nutrients.

OR

Basis of Comparison	organic fertilizers	Inorganic fertilizers
Source	Living	Non-living
Type	Natural	Synthetic
Release speed	Slow	Fast
Absorption	Varies depending on the source of the fertilizer	Maximum
Use	Small or medium lands	Big lands
Source materials	Manure, leaves, sticks, fruits, bone, flour, flowers	Rocks, sand, petroleum, air, natural gas, methane

5. Write short answers of following questions.
(i) Why fertilizers are necessary for plant?
Ans: Fertilizers Are Necessary For Plants:

• Fertilizers are substances containing chemical elements such as manure of mixture of nitrates that improves the growth of plants.
• They give nutrition to the crops and produce more fruit, faster growth, more attractive flowers.
• When added to soil or water, plants can develop tolerance against pests like weeds, insects and diseases.
• The use of manure and composts as fertilizers is probably almost as old as agriculture.
• Modern chemical fertilizers include one or more of the three elements that are most important in plant nutrition: nitrogen, phosphorus, and potassium.
• Chemicals fertilizers are simply that nutrients applied to agricultural fields to supplement required elements found naturally in the soil.

OR

Ans: Fertilizers are important for plants because:

• They contain chemical elements mixture of nitrates that improves the growth of plants.
• They give nutrition to the crops and produce more fruits and more attractive flowers.
• When fertilizers are added to soil or water, plants can develop tolerance against pests like weeds, insects and diseases.
• Modern chemical fertilizers include one or more of the three elements, nitrogen, phosphorus, and potassium that are most important in plant nutrition.
• Chemicals fertilizers act as nutrients to plants.

(ii) How stomach linings are protected from acidic environment?
Ans: Our stomach protects itself from being digested by its own enzymes, or burnt by the corrosive hydrochloric acd, by secreting sticky, neutralising mucus that clings to the stomach walls. If this layer becomes damaged in any way it can result in painful and unpleasant stomach ulcers.
The stomach is protected by the epithelial cells, which produce and secrete a bicarbonate rich solution that coats the mucosa. Bicarbonate i alkaline, a base, and neutralizes the acid secreted by the parietal cells, producing water in the process. This continuous supply of bicarbonate is the main way that your stomach protects itself from auto-digestion (the stomach digesting itself) and the overall acidic environment.

OR

Ans: The stomach protects itself from being digested by its own enzymes, or burnt by the corrosive hydrochloric acid, by secreting a sticky, neutralizing mucus that clings to the stomach walls. If this layer becomes damaged in any way it can result in painful and unpleasant stomach ulcers.

(iii) Why nitrogen is essential for plants?
Ans: Ans: Nitrogen is essential for plants to synthesize amino acids, which are the building blocks for protein synthesis and also required for the production of chlorophyll, nucleic acids, and enzymes. For all metabolic elements which plants use from soil, nitrogen needs in the largest amounts.

(iv) Why fats are called most efficient form of food?
Ans: Fats are the slowest source of energy but the most energy-efficient form of food. Each gram of fat supplies the body with about 9 calories, more than twice that supplied by proteins or carbohydrates. Because fats are such an efficient form of energy, the body stores any excess energy as fat. The body deposits excess fat in the abdomen (omental fat) and under the skin (subcutaneous fat) to use when it needs more energy.

(v) Why grinding and lubrication are necessary for swallowing?
Ans: Grinding of food: The second function of oral cavity is the grinding of food by teeth. It is known as chewing or mastication. It is useful because oesophagus can pass only small pieces through it as well as enzymes cannot act on large pieces of food.

Lubrication of food: The third function of the oral cavity is lubrication of food by mixing saliva secreted by saliva. It has two main functions.

• Adds water and mucus to the food.
• Partial digestion of starch by saliva which contains an enzyme salivary amylase.

Than the pieces of food are rolled up by the tongue into small, slippery, spherical mass called bolus.
As chewing continue the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed easily.

6. Write detailed answers of the following questions.
(i) Describe environmental hazards related to chemical fertilizers.
Ans: Environmental Hazards Related To Chemical Fertilizers:
An environmental hazard is a condition, which has the potential to threat natural environment or adversely affect people's health, including pollution and natural disasters. The farmers apply fertilizer for better growth of their crops, but on the other side these fertilizers pollute water and soil as well.

1. Soil nutrient holding capacity:
   The massive quantities of inorganic fertilizers affect the soil nutrient holding capacity.
2. Eutrophication:
   The high solubility of fertilizers also degrade ecosystem through eutrophication (means an increase in chemical nutrients typically compounds containing nitrogen or phosphorus in an ecosystem).
3. Emission of greenhouse gas:
   Storage and application of some nitrogen fertilizers may cause emission of greenhouse gas, e.g nitrous oxide.
4. Soil acidity:
   Ammonia gas (NH₃) may be emitted from applied inorganic fertilizers. This extra ammonia can also increase soil acidity.
5. Pest problems:
   Excessive nitrogen fertilizers can lead to pest problem by increasing their reproduction rate.
6. Nutrient balance:
   It is recommended that nutrient content of the soil and nutrient requirement of crop should be carefully balanced with application of inorganic fertilizers. It is critical to apply no more than it is needed; any excess in nutrient will definitely develop pollution of any kind.

(ii) Describe function of stomach and intestine with suitable diagram of human digestive system.
Ans: Function Of Stomach:

• Break Food into small pieces: The stomach muscles churn and mix the food with acids and enzymes, breaking it into much smaller, digestible pieces. An acidic environment is needed for the digestion that takes place in the stomach.
• Gastric Juice: Glands in the stomach lining produce about 3 quarts (2.8 liters) of these digestive juices each day. When food enters into the stomach the gastric juice is secreted by gastric glands found in the stomach wall. It is composed of:
  * Mucous,
  * Hydrochloric acid and
  * Protein digesting enzyme pepsinogen.
  Hydrochloric acid converts the inactive enzyme pepsinogen into active form called pepsin. HCl also kills micro-organisms present in food.
• Mucous Protection: Stomach is protected against the action of acid by mucus.
• Enzyme Pepsinogen (Pepsin): Pepsin partially digests the protein portion of the food into polypeptides and shorter peptide chains.
• Churning Of Food: In stomach food is further broken apart through a process called churning. The walls of stomach contract and relax and these movements help in mixing of the gastric juice and food. The churning action also produces heat which helps to melt the lipid contents of the food.
• Chyme: By the time food is ready to leave the stomach, it has been processed into a thick paste like liquid called chyme. The pylorus keeps chyme in the stomach until it reaches the right consistency to pass into the small intestine. Chyme is then squirted down into the small intestine, where digestion of food continues.

Function Of Intestines:
Function Of Small Intestine:
The small intestine is made up of three parts: Duodenum, Jejonum And Ileum

Duodenum:
It is the first part of small intestine which is about 25 cm (10 inches) long. It is C-shaped part of small intestine.
Function Of Duodenum:
The duodenum receives chyme from the stomach and it is a part of alimentary canal where most of the digestive process occurs. Ducts that enter into the duodenum deliver pancreatic juice and bile from the pancreas and liver, respectively.

• Bile salts have detergent action on particles of dietary fat which causes fat globules to break down or be emulsified into minute, microscopic droplets.
• Pancreatic juice is a liquid secreted by the pancreas, which contains a variety of enzymes, including:
  * Protease like trypsinogen: Coverts proteins (polypeptides) into amino acid.
  * Pancreatic lipase: Converts fats into fatty acid and glycerol.
  * Amylase: Converts carbohydrates into glucose (simple sugar).
• Intestinal juices produced from the small intestine contain enzymes and pancreatic juice break down all four groups of molecules found in food (polysaccharides, proteins, fats, and nucleic acids) into their component molecules.

Function Of Jejonum:
It is coiled shaped mid section of small intestine.

Ileum:
It is the final section of small intestine which leads into the large intestine.
Function Of Ileum (Absorption):
The inner wall of the small intestine is covered with millions of microscopic, finger-like projections called villi (singular, villus). Each villus is connected and richly supplied with blood capillaries and lymphatic vessels, i.e lacteal. The villi are the vehicles through which nutrients can be absorbed into the body. They increase the surface area over which absorption and digestion occur. These specialized cells help absorbed materials (simple sugars, amino acids and nucleosides) cross the intestinal lining into the bloodstream.
From the small intestine,the undigested food travels to the large intestine through a muscular ring, that prevents food from returning to the small intestine.

Large Intestine:
The large intestine is made up of three parts:

1. Caecum
2. Colon
3. Rectum

Function Of Large Intestine: The large intestine's main function is to remove water from the undigested matter and form solid waste that can be egested.
1. The Caecum:
is a pouch at the beginning of the large intestine that joins the small intestine to the large intestine. This transition area expands in diameter, allowing food to travel from the small intestine to the large. The appendix, a small, hollow, finger-like pouch, hangs at the end of the caecum. It is no longer appears to be useful to the digestive process.

2. The Colon:
extends from the caecum up the right side of the abdomen, across the upper abdomen, and then down the left side of the abdomen, finally connecting to the rectum. The colon has three parts, the ascending colon, transverse colon and descending colon.
Function: The ascending colon and transverse colon absorb fluids and salts, and the descending colon holds the resulting waste (faeces). Faeces mainly consist of undigested material, large number of bacteria, sloughed off gastrointestinal cells, bile pigments and water. Bacteria in the colon help to digest the remaining food products.

3. Rectum:
is the last part of large intestine. It opens to the outside by anus.
The rectum is where faeces are stored until they leave the digestive system through the anus as a bowel movement.

Human Digestive System

(iii) What are vitamins? Describe types of vitamins
Ans: VITAMINS:
A vitamin is an organic molecule (or related set of molecules), an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. They are for maintaining normal health and development. Lack of vitamins can cause several diseases.
Source Of Vitamins:
Milk, Fruits and Vegetables.

TYPES OF VITAMINS:
They are divided into two types:

1. Fat Soluble Vitamins:
   Vitamin which can soluble in organic solvent are called Fat-soluble vitamins (A, D, E and K) are less excreted from the body as compared to water-soluble vitamins.
2. Water Soluble Vitamins:
   Vitamin which are soluble in H₂O. These are vitamins B and C. Cooking or heating destroys the water soluble vitamins more readily than the fat-soluble vitamins.

Functions, chemical names and deficiencies of important vitamins

Vitamin generic name	Deficiency diseases
Vitamin K	Bleeding disorder
Vitamin D	Rickets and osteomalacia
Vitamin C	Scurvey
Vitamin B	Beriberi
Vitamin A	Night blindness, eye-infection, rough skin, respiratory infections

(iv) Describe mineral deficiency diseases in human.
Ans: Mineral Deficiency Disease:
Diseases resulting from deficiency of a mineral are relatively rare among humans some are given below:
1. Goiter:
Symptoms: Goiter is a condition in which thyroid gland becomes enlarged and it results in swelling in neck.
Cause: Goiter is caused by an insufficient amount of “Iodine” in diet. Iodine is used by thyroid gland to produce hormones that control the body's normal functioning and growth.

2. Anemia (most common of all mineral deficiency diseases):
The term anemia literally means “a lack of blood”.
Cause: The condition is caused when number of red blood cells reduced to a level lower than normal. Haemoglobin molecule contains four atom of iron. If body fails to receive sufficient amount of iron, an adequate number of haemoglobin will not be formed. So, there are not enough functioning red blood cells.
Symptoms: A person becomes weak and there is shortage of oxygen supply to body's cells.

(v) Describe effects of malnutrition on human.
Ans: The Effects Of Malnutrition:
Malnutrition hurts people both mentally and physically. The more malnourished a person is; the more nutrients the person is missing, the more likely person will experience health issues. Some of them are given below:
1. Starvation:
It is a severe deficiency in caloric energy intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death.

2. Heart Diseases:
The term "heart disease" is often used interchangeably with the term "cardiovascular disease." Cardiovascular disease generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain (angina) or stroke. 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.

3. Constipation:
People do not schedule their meals. This irregularity cause many health problems like constipation. It can be well defined, a condition in which there is difficulty in emptying the bowels, usually associated with hardened faeces.

4. Obesity:
It is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health. Obesity is most commonly caused by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. Obesity is known as mother disease and may lead to heart problems, hypertension, diabetes etc.

More Short Questions Answers

1. Differentiate between:
(a) Carnivores and Herbivores
(b) Digestion in stomach and Digestion in intestine
Ans: (a) Difference Between Carnivores and Herbivores

S.No	Carnivores	Herbivores
1.	Those animals which feed upon other animals are called carnivores.	Those animals which use plants for their food are called herbivores.
2.	They have sharp, long strong and pointed canine teeth.	They do not have strong, and pointed canines.
3.	Cat, dog, lion are carnivores.	Horse, Deer and cattle are herbivores.

(b) Difference Between Digestion in stomach and Digestion in intestine

S.No	Digestion In Stomach	Digestion In Intestine
1.	Gastric glands are present in stomach.	Intestinal glands are present in small intestine.
2.	Gastric glands secrete gastric juice.	Intestinal glands secrete intestinal juice.
3.	Food becomes acidic due to the presence of HCl in stomach.	Food is neutralized due to bile and pancreatic juices.
4.	Food is partially digest in stomach.	Food is completely digest in intestine.
5.	No absorption or egestion process occur	Absorption process occur in small intestine and egestion process occur in large intestine.