Class VII – Science
Chapter 2: Nutrition in Animals
I. Fill in the blanks
- __________ is the process of taking in food by an organism and its digestion, absorption, and utilization in the body.
Answer: Ingestion
- The __________ is a nutrition in which an organism takes in food by feeding upon it and then energy for life processes.
Answer: Heterotrophic
- The process of taking food by an organism is called __________.
Answer: Ingestion
- The process by which undigested food is removed from the body is called __________.
Answer: Egestion
- The food passes through a long muscular canal __________ that begins at the __________ end at the anus.
Answer: Alimentary canal
- The glands associated with the alimentary canal are __________ and pancreas.
Answer: Salivary glands
- The buccal cavity contains the __________, __________, and __________.
Answer: Teeth, tongue
- The salivary glands produce a digestive juice called __________ which breaks down the present in the food into sugars.
Answer: Saliva
- The __________ is a fleshy, muscular organ attached at the back to the floor of the buccal cavity.
Answer: Tongue
- The process of chewing breaks down the food into small pieces and mixes it with saliva known as __________.
Answer: Mastication
- The white and hardest substance that covers the teeth is called __________.
Answer: Enamel
- The bacteria present in our mouth react with leftover food and the saliva which forms then, sticky layer called __________.
Answer: Plaque
- Plaque, if not removed by brushing forms __________ with the sugar present in the food.
Answer: Cavities
- Digestion does not take place in the __________ or __________.
Answer: Oesophagus, large intestine
- The pushing down of food by the walls of the oesophagus is called __________.
Answer: Peristalsis
- The inner wall of the stomach contains __________ which secrete digestive juices that contain three substances: __________, __________, and __________.
Answer: Gastric glands, hydrochloric acid, pepsin, mucus
- __________ kills the bacteria that enter with the food in the stomach.
Answer: Hydrochloric acid
- The __________ protects the inner lining of the stomach from the action of the acid.
Answer: Mucus
- The small intestine receives secretions from two glands, the __________ and __________.
Answer: Liver, pancreas
- The __________ is a reddish-brown gland situated in the upper part of the abdomen.
Answer: Liver
- __________ is the largest gland in our body that secretes __________, which is stored in a sac called __________, which helps in the digestion of __________.
Answer: Liver, bile juice, gallbladder, fats
- The __________ acts on carbohydrates and proteins and changes them into simpler forms.
Answer: Pancreatic juice
- The process of digestion completes in the __________.
Answer: Small intestine
- The process of absorption of food occurs in the __________.
Answer: Small intestine
- The large intestine has two parts – __________ and the __________. The colon absorbs __________ and __________ from undigested food.
Answer: Colon, rectum, water, salts
- The partially digested food in ruminants is called __________.
Answer: Cud
- The process in which cud returns to the mouth as small lumps and the animals chew it a second time is called __________.
Answer: Rumination
- In animals like horses, rabbits cellulose is digested in a specialized organ called __________, which is a large sac-like structure present between __________ and __________.
Answer: Caecum, small intestine, large intestine
- __________ provide a large surface area for the absorption of digested food in the small intestine.
Answer: Villi
- __________ is the organ that is involved in the digestion of milk protein in infants.
Answer: Rennin
II. Name the following
- Name the part of the alimentary canal that is involved in respectively-
- a) Killing of bacteria
Answer: Stomach
- b) Chewing of food
Answer: Buccal cavity
- c) Absorption of digested food
Answer: Small intestine
- a) Killing of bacteria
- Name the organ involved in the absorption of water.
Answer: Large intestine
- Process of pushing down of food by the oesophagus.
Answer: Peristalsis
- Widest part of the alimentary canal.
Answer: Stomach
- Longest part of the alimentary canal.
Answer: Small intestine
- Largest gland in the body that helps in the digestion of fats.
Answer: Liver
- Ends product of digestion of-
- a) Carbohydrates
Answer: Glucose
- b) Proteins
Answer: Amino acids
- c) Fats
Answer: Fatty acids and glycerol
- a) Carbohydrates
- Finger-like projection in the inner wall of the small intestine.
Answer: Villi
- White and hardest substance that covers the teeth.
Answer: Enamel
- Special structure present in the following for the ingestion of food-
- a) Human beings
Answer: Mouth
- b) Paramecium
Answer: Cilia
- c) Hydra
Answer: Tentacles
- d) Frog
Answer: Sticky tongue
- e) Insects
Answer: Proboscis
- a) Human beings
III. Analogy Based Questions
- Frog: Sticky tongue:: Insects: __________
Answer: Proboscis
- Incisors: __________:: Premolars: 8
Answer: 4
- Stomach: __________:: Liver: Reddish brown gland
Answer: Muscular sac
IV. Correct the underlined word
- The undigested semisolid waste known as faeces is passed into the colon.
Answer: Rectum
- Consumption of unclean water or dirty food results in dehydration.
Answer: Diseases
- The carbohydrates get broken down into amino acids.
Answer: Simple sugars
- Pancreas is the largest gland in our body.
Answer: Liver
V. Assertion Based Questions
Use the following key to choose the appropriate answer:
- (a) Both A and R are true and R is the correct explanation of A.
- (b) Both A and R are true but R is not the correct explanation of A.
- (c) A is true but R is false.
- (d) A is false but R is true.
- Assertion (A): Rumen is the first of four chambers of the stomach of ruminants.
Reason (R): In rumen, the food gets partially digested and is called cud.
Answer: (a) Both A and R are true and R is the correct explanation of A.
- Assertion (A): Liver secretes juice called bile juice.
Reason (R): Bile juice is stored in the liver.
Answer: (b) Both A and R are true but R is not the correct explanation of A.
- Assertion (A): Food is pushed down the food pipe which runs through the neck and chest.
Reason (R): The peristaltic movement of the wall of the food pipe is a continuous process.
Answer: (a) Both A and R are true and R is the correct explanation of A.