Science 5 Marks Questions

Column I	Column II
Salivary gland	Saliva secretion
Stomach	Acid release
Liver	Bile juice secretion
Rectum	Storage of undigested food
Small intestine	Digestion is completed
Large intestine	Absorption of water

Similarity between nutrition in Amoeba and human beings:

Both Amoeba and humans require energy for the growth and maintenance of their bodies. This energy is derived from the food that they eat. The food that they consume is always in a complex form and is therefore broken down into simpler forms by the process of digestion. Hence, both these organisms are heterotrophs.

Differences between nutrition in Amoeba and human beings:

Digestion in Humans	Digestion in Amoeba
Humans have a mouth and a complex digestive system.	Mouth and digestive system are absent in Amoeba.
Digestive juices are secreted in the buccal cavity, stomach, and small intestine.	Digestive juices are secreted in the food vacuole.
Digestion of carbohydrates, proteins, and fats starts in separate regions.	All the food components are digested in the food vacuole

Sweets and Tooth Decay The tooth is covered by white, hard outer covering of tooth called Enamel enamel below which dentine is present. It is similar to bone which Pulp cavity (with nerves and blood vessels) protects the pulp cavity having nerves and blood vessels. Bacteria are Gum present in our mouth but they are not harmful to us. However, if we do not clean our teeth and mouth after eating, many harmful bacteria also begin to live and grow in it. These bacteria breakdown the sugars present from the leftover food and release acids. The acids gradually damage the tooth. This is called tooth decay.
Therefore, tooth decay is defined as the process of rotting of tooth and formation of cavity or holes in it which leads to the toothache.
When the holes or cavity reaches to the pulp cavity, it causes pain. If these cavities are not treated on time it causes severe toothache and may result in tooth loss.

Tooth decay can be prevented by adapting following measures:

1. One should rinse and clean its teeth thoroughly after every Pulp cavity meal.
2. We should clean our teeth with the help of datun or brush Gradual decaying of human tooth and toothpaste, twice a day.
3. We should use dental floss which is a special strong thread. It is moved between two teeth to take out trapped food particles.
4. Dirty fingers or unwashed objects must be avoided to put in the mouth.
5. We should avoid the use of sweets, chocolates, toffees, ice-cream, etc. Much use of cold drink should also be avoided.

Name of animal	Kind of food	Mode of feeding
Snail	Leaves and insects	Scraping
Ant	Food particles	Chewing
Humming bird	Nectar of flower	Sucking
Lice	Blood	Sucking
Mosquito	Blood	Sucking
Butterfly	Nactar of flower	Siphoning
Housefly	All most everything	Sponging

Solution is as follows:

1. Bile juice is secreted by the liver.
2. Digestion of fats is difficult as compared to that of other nutrients because of insolubility of fat in water.
3. Bile juice helps in digestion of fat by breaking down big fat droplets into smaller droplet. This is called emulsification of fats.
4. Digestion of fat is completed in small intestine.
5. No, fat is not digested by bile juice. Bile contains bile salts, which helps in its emulsification. This makes the action of pancreatic lipase easier that completes fat digestion.