Nutrition In Animals

Starch gives blue black colour when tested with iodine. Among the given options, boiled & mashed potato and bread slice will have starch in them therefore, they will give blue black colour with iodine.

While mustard oil and glucose solution doesn't not have starch content in them. They have fats and glucose content respectively.

Molars: These are the largest teeth of all. They are 12 in number. Their function is to grind and crush food.

Premolars: The teeth present next to molars are the premolars. They are 8 in number. They also perform the same function as that of molars i.e. grinding and crushing of food.

*premolars and molars have a flat top surface.

Canines: these are the next set of teeth. They are 4 in number. Their main work is to tear the food. These are present mainly in the carnivorous animals.

Incisors: These are the first set of teeth which develop in a baby. They are total 8 in number and are located exactly in front of the mouth. They are used for biting.

Oesophagus: It is a long tubular part which connects the buccal cavity to the stomach. It only provides passage of food and here no digestion takes place.

Large intestine: This is the coiled part of intestine which is responsible for absorption of water.

Rectum: This is the last stop for food in the human body. It stores the food before it is eliminated out of the body.

*The digestion starts in the buccal cavity by the action of salivary amylase which starts digestion of starch and then it is transported to the stomach through the oesophagus where the rest of digestion takes place.

The food we take from our buccal cavity moves down the stomach through the oesophagus because of the contraction of the muscle present in the food pipe. This process of muscle contraction is known as peristalsis.

The acid present in the stomach is the Hydrochloric acid which is secreted by the oxyntic or the parietal cells of the stomach. They help in killing the harmful bacteria that may enter our body along with the food. With this they also make the medium acidic which further helps in protein digestion.

The small finger like projections which are present in the small intestine are known as villi. Villi has many infoldings which increase the surface area for absorption. It increase the absorption area to many folds and the digested food in the small intestine is absorbed easily and quickly through this.

Villi are thousands of finger like projections present in the small intestine which increase the surface area for absorption. They have very thin walls along with a network of thin capillaries which are present very near to the surface of villi and help in absorption of the food. This absorbed food is transported to different organs of the body via blood and used for further body functions. This process of absorption of food is known as assimilation.

Amoeba is a single celled organism which produces many finger like projections known as parapodia. These parapodia help in the movement of the organism, therefore also known as false feet. Along with movement it also help in capturing of the food particles. Pseudopodia are formed and the target food particle is ingested.

The salivary glands present in the buccal cavity release an enzyme known as salivary amylase (ptylin). This enzyme is responsible for the breakdown of starch into simpler sugars. Hence, the process of digestion starts in our mouth itself. Further sugar digestion occurs in the stomach.

The animals every time cannot get food whenever they are hungry instead they need to store the food whenever it is available to them. So, some animals like cows swallow a large amount of food at once and it gets stored in a different part of stomach known as rumen. Here the food is stored as well as partially digested. Now this swallowed, stored and partially digested food is known as cud which returns to mouth for chewing. The animals having this practice are known as ruminants and the process is known as rumination.

There are some animals which swallow a large amount of food when it becomes available to them and store it in a separate part of the stomach which is known as rumen. Here the food is partially digested and now known as cud. After this the cud returns to the mouth in small amounts and proper chewing of cud takes place and then it moves to the alimentary canal where complete digestion of food takes place.

Cellulose is a component present in plant cell wall. Human beings are unable to digest this cellulose because of absence of enzyme cellulase in the body which helps in cellulose digestion.

(i) The part of alimentary canal where water gets absorbed from the undigested food is the large intestine.

(ii) The digested food in the human body gets absorbed in the small intestine. Maximum absorption takes place here.

(iii) Taste buds present on our tongue are responsible for the taste of different kinds of food.

(iv) Liver, the largest gland of human body produces bile juice which is then further stored in the gall bladder.

(a) True. Our tongue is attached to the roof of the mouth cavity at the back and the front is free moving.

(b) False. The large intestine is shorter and wider than the small intestine of the human alimentary canal.

(c) True. The mucus present in our stomach protects the stomach lining from the harmful effects of the hydrochloric acid.

(d) True. All heterotrophs have similar basic nutrition as they take food from outside sources instead of producing their own food.

(i) Starch : liver, salivary gland and gall bladder are all parts of the alimentary canal. They either produce an enzyme or store it. It facilitates digestion. Whereas starch is a type of food.

(ii) Stomach: liver, pancreas and salivary glands are the glands which produce enzymes.

(iii) Absorption : Tasting and swallowing are the functions performed by a tongue but it never helps in absorption.

(iv) Small intestine. Oesophagus, large intestine and rectum are not involved in any type of food digestion. Oesophagus provides a passage for food ttransfer, large intestine is mainly involved in water reabsorption from undigested food, while rectum temporarily stores faeces. Only small intestine is involved in digestion of food

The two drinks could be easily distinguished by tasting them. We have different receptors for different tastes present on our tongue. These taste buds or receptors helps us in identifying various tastes.

lime juice is identified by sour taste bud, located at the edges of tongue, while gourd juice is identified by taste bud of bitter taste, located at the bottom of tongue.

(a) The alimentary canal stretches from the buccal cavity to the anus.

buccal cavity is the starting point of alimentary canal, while it terminates at anus.

(b) Teeth are rooted in separate sockets in between the gums.

human teeth are thecodont, i.e. they are fitted into a socket.

(c) Digestion of food starts in the buccal cavity and gets completed in the small intestine.

buccal cavity initiates the process of digestion by partially digesting starch. While in small intestine the process of digestion gets completed. Large intestine is not involved in digestion process, it only absorbs water form undigested food.

(d) Liver is the largest gland in the human body.

liver is the largest gland in human body which helps in various life processes.

(a) Assimilation. It is the process of transportation of absorbed food to different parts of body and their utilization.

(b) Digestion. It is the process of breaking of large and complex food substances into simpler and soluble substances. It is a type of catabolic reaction.

(c) Egestion. It is the process of removal of undigested food particles from the body.

(d) Ingestion. The process of taking the food materials into one’s body is known as ingestion.

(e) Absorption. The process of transport of digested and soluble food from the intestine to blood vessels is known as absorption.

(a) housefly = (iii) sponging

sponging mode of feeding is present in insects which helps them sucking food without cutting or tearing the food particle.

(b) cockroach = (i) biting and chewing

cockroaches have basic arrangement of teeth, which helps them biting and chewing food particles.

(c) mosquito = (iv) sucking

mosquitoes feed by sucking blood from bodies of humans and other animals.

(d) infants = (ii) suckling

suckle means feeding a baby or young animal from breast.

In the first case when we iodine solution is added to the boiled rice, a colour change is observed. The colour becomes blue black because of the presence of starch in the boiled rice. But in the second case when the rice is boiled and chewed, after the addition of iodine solution to it, the color do not change because of the activity of salivary amylase on starch. The salivary amylase converts the starch into maltose and hence it gives a negative test for starch.

Gallbladder is a small sac like structure which stores and concentrates the bile juice produced by the liver. This bile produced helps in the emulsification of fats i.e. breakdown of complex fat molecules into smaller particles. The gall bladder stores the bile and uses it when needed but now as it is surgically removed there is no place for bile storage and hence when this person eats food containing large amount of fat she faces problems with digestion.

(a)rectum = (iv) faeces. Rectum is the last part of large intestine which temporarily stores the undigested food and help in faecal discharge.

(b) gall bladder =(v) bile. Gall bladder is a sac like structure situated near the liver which helps in storage and concentration of bile juice.

(c) stomach = (i) mucous. Mucous neck cells present in the internal wall of stomach secretes mucus which protects the stomach lining from the highly acidic nature of hydrochloric acid.

(d) tongue = (iii) taste buds. Tongue is a muscular organ present in the buccal cavity. It bears taste buds which help in perceiving different tastes.

(e) small intestine = (ii) villi. Villi is the numerous infoldings present in the small intestine. It increases surface area for absorption.

The animals cannot get food whenever they are hungry instead they need to store the food whenever it is available to them. So, some animals like cows and buffaloes swallow a large amount of food at once and it gets stored in a different part of stomach known as rumen. Here the food is stored as well as partially digested. Now this swallowed, stored and partially digested food is known as cud which returns to mouth for chewing. The animals then sit restfully and then chew their food properly which is then digested fully. The animals having this practice are known as ruminants and the process is known as rumination.

Pharynx is a common passage for food and air. This is a place which has openings for both food pipe and windpipe. A cartilaginous flap called epiglottis prevents the entry of food into the wind pipe by covering the opening of windpipe during swallowing. When we eat the food in hurry the epiglottis gets confused between the windpipe and the food pipe and the food goes into the wind pipe thus causing violent coughing. So we must never eat our food in hurry.

(a) The digestion of all food components is completed by the intestinal juices. These are a group of enzymes which help in complete digestion of food.

(b) Large intestine absorbs water and some salts from the undigested food.

(c) Tongue is attached at the back to the floor of the mouth cavity and is free at the front. It is a muscular organ which helps in wallowing of food.

(d) Amoeba pushes out pseudopodia around the food and traps it in a food vacuole. The pseudopodia also help in the movement along with the food intake.

(i) The cutting and biting teeth labelled as A are the incisors. They are the first teeth to develop in an infant. They are present in the front and are 8 in number.

(ii) The piercing and tearing teeth labelled as ‘B’ are the canines. They are 4 in number are present chiefly in the carnivorous animals.

(iii) The grinding and chewing teeth labelled as ‘C’ are the premolars. They are also 8 in number. They have a flat chewing surface.

(iv) The grinding teeth present only in adult labeled as ‘D’ are the molars. They are 12 in number and are present in adults.

(a) Liver, the largest gland of the human body produces bile juice which gets stored in gall bladder and used when required.

(b) Digestion of fats is difficult because they are water insoluble and are present as large globules.

(c) Bile juice helps in emulsification of fats which means breakdown of larger fat molecules into smaller ones. This way bile juice helps in digestion of fat molecules.

(d) The digestion of fats get completed in small intestine. Fat emulsification is done by bile juice, which is secreted by liver, stored in gall bladder, and released in small intestine. As it is released in small intestine, fat emulsification gets completed in small intestine only.

(e) No, bile juice do not help in digestion of fat completely but it converts the bigger fat molecules into smaller droplets which makes it easier to get digested.

(a) Liver is the largest gland of the human body.

(b) Digestion of protein starts in the stomach of human body.

(c) Pancreas is the organ that releases digestive juices into the small intestine.

(d) Liver produces bile juice which gets stored in the gallbladder which is then released in the small intestine for the emulsification of fat molecules.

(a) Yes there is a difference in the number of teeth and the type of teeth shown in the figure and in the mouth. The difference was in the molars. In the diagram given 12 molars as shown whereas in my mouth I cannot find any molar.

(b) In an adult total number of teeth are 32 Where are there are only 20 teeth in my mouth. The difference are in the number of molars. There are no molars in my mouth whereas there are all 12 molars in my parents mouth.

Across:-

1. Cream-coloured digestive gland - [pancreas]

3. Undigested excretory solid residues - [faeces]

4. Organ that mixes saliva with the food - [tongue]

5. Point of defecation - [anus]

7. Stored in gall bladder - [bile]

10. Finger-like outgrowth in the small intestine - [villi]

13. Kind of taste buds - [sour]

14. Kills bacteria in the stomach - [acid]

Down:-

2. Feeds with the help of pseudopodia - [amoeba]

6. Total number of molars in one jaw of an adult - [six]

8. Largest gland - [liver]

9. Watery secretion in the mouth - [saliva]

11. A ruminant - [cow]

12. Form of food chewed by ruminants - [cud]