Important Questions for Class 7 Science - Nutrition in Animals

Very Short Answer Type Questions

Q1: What is the process of taking in food called?
Ans: Ingestion.

Q2: What is the flap-like valve that prevents food from entering the windpipe called?
Ans: Epiglottis.

Q3: Which organ produces bile juice?
Ans: Liver.

Q4: What is the role of bile in digestion?
Ans: Bile helps digest fats by breaking them into tiny droplets, increasing their surface area for digestion.

Q5: What are the finger-like projections on the inner walls of the small intestine called?
Ans: Villi.

Q6: What is the process of utilizing absorbed food for various activities called?
Ans: Assimilation.

Q7: What is the undigested waste material called that enters the large intestine?
Ans: Faeces.

Q8: What is the process of bringing back partially digested food to the mouth for additional chewing in ruminants called?
Ans: Rumination.

Q9: What is the complex carbohydrate found in the diet of herbivorous animals?
Ans: Cellulose.

Q10: What is the locomotory organ of amoeba?
Ans: Pseudopodia.

Short Answer Type Questions

Q11: Describe the process of digestion in the human stomach.
Ans: In the human stomach, food is digested with the help of gastric juice secreted by gastric glands. The stomach is a muscular organ that churns and mixes the food with gastric juice, which contains hydrochloric acid and digestive enzymes. This process breaks down food into simpler forms for absorption.

Q12: Explain the role of the liver and pancreas in digestion.
Ans: The liver produces bile juice, which is stored in the gall bladder and released into the duodenum. Bile helps digest fats by breaking them into tiny droplets. The pancreas secretes pancreatic juice containing enzymes that digest carbohydrates, proteins, and fats into simpler forms.

Q13: How are absorbed nutrients utilized in the body?
Ans: Absorbed nutrients such as glucose, amino acids, fatty acids, and glycerol are utilized in the body through a process called assimilation. These nutrients are used for various activities, including providing energy for metabolic processes, growth, maintenance, and repair of cells and tissues.

Q14: What is the function of the large intestine in digestion?
Ans: The large intestine absorbs water and salts from undigested food material. It helps in concentrating the waste material, forming faeces. Faeces are temporarily stored in the rectum and eliminated through the anus in a process called egestion.

Q15: Why can't humans digest cellulose, even though it is present in their diet?
Ans: Humans lack the necessary enzymes and symbiotic bacteria to digest cellulose. Grass-eating animals like cows have specialized stomachs with symbiotic bacteria that can break down cellulose, but humans do not possess these adaptations.

Q16: Explain how amoeba obtains and digests its food.
Ans: Amoeba engulfs its prey along with a droplet of water using pseudopodia, forming a food vacuole inside the cytoplasm. Digestive enzymes secreted by the food vacuole break down the prey. Undigested food is expelled by changing the shape of the amoeba.

Q17: What are the structures found in the cytoplasm of an amoeba?
Ans: The cytoplasm of an amoeba contains structures such as the nucleus, food vacuoles, and contractile vacuoles.

Q18: How does an amoeba respire and excrete waste products?
Ans: An amoeba takes in dissolved oxygen through the cell membrane by diffusion and releases carbon dioxide into the surrounding water. Waste products are eliminated by expelling undigested food and forming a protective cyst in unfavorable conditions.

Q19: What is the significance of villi in the small intestine?
Ans: Villi are small finger-like projections on the inner walls of the small intestine that increase the surface area for absorption of digested food. This allows for efficient absorption of nutrients into the bloodstream.

Q20: What is rumination, and why do ruminants practice it?
Ans: Rumination is the process of bringing back partially digested food to the mouth for additional chewing. Ruminants like cows, buffaloes, and sheep practice rumination because they have specialized stomachs with four chambers, and they need to thoroughly digest cellulose present in their plant-based diet.