NUTRITION IN ANIMALS- Long Question And Answer
Table of Contents
Explain the process of digestion and its importance in the utilisation of food by the body.
Answer- Digestion is the process of breaking down complex food components into simpler substances for absorption and utilisation. Enzymes and chemical reactions in the digestive system facilitate this process. Digestion allows the body to extract essential nutrients for energy, growth, and repair.
Describe different ways in which organisms acquire food based on their specific adaptations.
Answer- Organisms have various ways to acquire food based on their adaptations. Examples include photosynthesis in plants, nursing from mother’s milk in infants, swallowing prey whole in snakes, and filtering tiny food particles from water in aquatic animals.
Describe the journey of food from the mouth to the small intestine and the role of each digestive organ along the way.
Answer- Food is chewed in the mouth, where mechanical digestion begins, and amylase in saliva initiates the chemical digestion of carbohydrates. The bolus is formed and swallowed, passing through the oesophagus to reach the stomach. In the stomach, gastric juices break down proteins, and mechanical churning forms chyme. From there, partially digested food moves to the small intestine, where the pancreas and liver contribute digestive enzymes and bile, respectively, to break down carbohydrates, proteins, and fats into simpler substances. Villi in the small intestine aid in nutrient absorption.
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Explain the significance of the alimentary canal in the process of digestion and nutrient absorption.
Answer- The alimentary canal, comprising the buccal cavity, oesophagus, stomach, small intestine, large intestine, rectum, and anus, is essential for the efficient digestion and absorption of nutrients. Each organ in this system has a specific role in breaking down food into simpler substances and absorbing nutrients. It ensures that digested nutrients, such as glucose and amino acids, are transported to various parts of the body for growth, repair, and energy production.
Explain the diverse functions of different types of teeth in the human mouth and how they contribute to the process of digestion.
Answer- Different types of teeth serve various functions in the mouth. Incisors are for cutting and biting, canines are for tearing, premolars are for grinding and crushing, and molars are for further grinding and crushing. These functions help in mechanically breaking down food into smaller pieces, increasing the surface area for enzymatic action in digestion. For example, incisors are useful for slicing fruits and vegetables, while molars are effective for breaking down tough or fibrous foods.
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Describe the process of mechanical and chemical digestion in the mouth and the role teeth and saliva play in this process.
Answer- Mechanical digestion in the mouth begins when food is chewed using teeth specialised for various functions. This action breaks down food into smaller, more manageable pieces, increasing the surface area for enzymatic action. Meanwhile, saliva, containing enzymes like amylase, is introduced, initiating the chemical digestion of carbohydrates. Amylase converts starches into simpler sugars, representing the first step in converting complex nutrients into forms absorbable by the body.
Explain the functions of saliva in the digestive process and how it prepares food for further processing in the stomach and small intestine.
Answer- Saliva plays a vital role in digestion by moistening food, making it easier to chew and swallow. It contains enzymes like amylase that initiate the breakdown of complex carbohydrates (starches) into simpler sugars. Saliva also aids in the initial stages of chemical digestion, preparing food for further processing in the stomach and small intestine.
Describe the two-stage process of tooth development in humans, including the roles of milk teeth and permanent teeth.
Answer- Tooth development in humans involves two stages. The first set of teeth, known as “milk teeth” or “primary teeth,” begins to erupt around six months of age and serves the essential role of allowing children to bite and chew food. As a child grows, milk teeth gradually become loose and fall out, typically between the ages of six to eight years. This natural process is followed by the emergence of “permanent teeth,” intended to last throughout a person’s life. The transition from milk teeth to permanent teeth is a crucial milestone in dental development.
Explain the process of tooth decay, from the interaction of harmful bacteria with sugars to the consequences of untreated decay.
Answer- Tooth decay occurs when harmful bacteria in the mouth interact with sugars from leftover food, producing acids that erode the enamel of teeth, leading to cavities. If left untreated, tooth decay can cause dental problems, toothache, sensitivity, and even tooth loss. In extreme cases, it can lead to gum disease and other serious oral health issues.
Describe the protective mechanism in the body that prevents choking when eating or drinking and the reflexes involved if food enters the windpipe.
Answer- The body’s protective mechanism during swallowing involves the epiglottis, a flap-like valve that closes off the windpipe (trachea) to prevent food and liquids from entering it. If food accidentally enters the windpipe, reflexes such as coughing, hiccups, or a choking sensation are triggered to expel the foreign material and protect the airway.
Describe the journey of food from the mouth to the stomach, including the role of the oesophagus and the process involved.
Answer- After food is ingested in the mouth, it travels down the oesophagus, a muscular tube that connects the mouth to the stomach. The oesophagus propels food downward through coordinated muscle contractions called peristalsis, ensuring it reaches the stomach smoothly.
Explain the function of the stomach in the digestive system and its position in the alimentary canal.
Answer- The stomach is a muscular, thick-walled organ that plays a pivotal role in food processing. It is positioned between the oesophagus and the small intestine. The stomach receives food from the food pipe and connects to the small intestine. Its functions include further mechanical digestion of food, mixing food with gastric juices, and initiating the chemical breakdown of proteins.
Explain the functions of the stomach in the digestive system, including the secretion of mucus, production of hydrochloric acid, and role in protein digestion.
Answer- The stomach serves several crucial functions in digestion. It secretes mucus to protect the stomach lining from stomach acid and digestive enzymes. It produces hydrochloric acid to create an acidic environment that kills harmful bacteria and activates digestive enzymes. The stomach also secretes digestive juices, including pepsin, which plays a critical role in breaking down proteins into simpler substances, known as peptides.
Describe the discovery of stomach function through the observations made by Dr. William Beaumont on Alexis St. Martin’s gunshot injury.
Answer- In 1822, Alexis St. Martin suffered a gunshot injury that created a hole in his stomach. Dr. William Beaumont treated him and used a bandage instead of properly closing the hole. This allowed Dr. Beaumont to make observations about stomach function through the hole. He found that the stomach churns food, secretes digestive fluids, and only empties its contents into the intestine once digestion is complete.
Explain the structural adaptations of the small intestine that make it efficient for nutrient absorption during digestion.
Answer- The small intestine has a highly coiled structure and is lined with finger-like projections called villi. This coiled structure and the presence of villi greatly increase the surface area available for the absorption of digested food components into the bloodstream. This adaptation ensures efficient nutrient absorption.
Describe the roles of the liver and pancreas in the digestive process within the small intestine, including the production of bile and pancreatic juice.
Answer- The liver produces bile, which is stored in the gallbladder. Bile plays a crucial role in the digestion of fats by emulsifying them, breaking them down into smaller droplets for easier digestion in the small intestine. The pancreas secretes pancreatic juice, which contains enzymes that act on carbohydrates, fats, and proteins, converting them into simpler forms during digestion in the small intestine.
Explain the process of absorption in the small intestine, including the role of villi and capillaries.
Answer- After digestion, the small intestine plays a crucial role in absorption. The inner walls of the small intestine are lined with villi, which greatly increase the surface area for absorption. Each villus contains a network of thin blood vessels (capillaries) close to its surface. These capillaries allow for the absorption of digested food materials, including glucose, amino acids, and fatty acids. These absorbed substances are then transported through the bloodstream to various organs in the body for utilisation.
Describe the role of the large intestine (colon) in digestion, including the formation of faeces and the process of egestion.
Answer- The large intestine serves to absorb water and some salts from the remaining undigested food material. As water is absorbed, the waste material becomes semi-solid, forming what is referred to as faeces. The faecal matter is then stored in the rectum until it is eliminated from the body through the anus in a process known as egestion.
Explain the process of rumination in ruminant animals and how it aids in cellulose digestion.
Answer- Ruminant animals like cows and buffaloes have a specialised digestive process that involves the rumen. They quickly swallow grass, which is stored in the rumen as cud. During rumination, they regurgitate small lumps of cud from their stomach and chew them thoroughly. This chewing action helps break down complex cellulose in grass into simpler, more digestible components, aiding in cellulose digestion.
Describe the adaptations in grass-eating animals like ruminants and those with a caecum that enable them to efficiently utilise cellulose-rich plant material as a food source.
Answer- Grass-eating animals like ruminants and those with a caecum have evolved specialised adaptations to digest cellulose-rich plant material efficiently. Ruminants have a rumen, where specialised bacteria break down cellulose into simpler sugars. Animals with a caecum have a large sac-like structure called the caecum, housing bacteria that assist in cellulose digestion. These adaptations enable them to utilise grasses and fibrous plants as a food source, which would be challenging for animals lacking these adaptations.
Describe the process of digestion in Amoeba, from the capture of food to the absorption of digested substances.
Answer- Amoeba captures food using pseudopodia, which form around the food particle. The food is engulfed and trapped in a food vacuole, where digestive juices are secreted. These juices break down the food into simpler substances. The digested food is then absorbed and used for growth, maintenance, and multiplication of Amoeba. Undigested residue is expelled outside the cell through vacuoles.
Explain the unique feeding strategy employed by starfish to access and consume animals with hard shells.
Answer- Starfish primarily feed on animals with hard shells, like certain mollusks and bivalves. They use their tube feet and arms to grasp and open the prey’s shell. Once the shell is open, the starfish extrudes its stomach through its mouth into the shell of the prey animal. Digestive enzymes are released to break down the prey’s body into simpler substances. After digestion is complete, the starfish retracts its stomach, leaving behind only the indigestible parts of the prey.
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