CBSE Class 6 Science Revision Assignment Set 01

Give reasons for the following questions:

Q3. Do you think it is better to eat a kotari of fat than a kotari of carbohydrates? Why?
Answer: No, it is not better to eat a bowl (kotari) of fat instead of carbohydrates. Although fats give much more energy than carbohydrates, eating too much fat can lead to a very harmful condition called obesity, where a person accumulates excess body fat and suffers from health issues like heart problems. Carbohydrates are our main source of energy and should form the major part of a balanced diet.
In simple words: Too much fat makes us obese and unhealthy, so carbohydrates are a safer and better primary energy source.

Exam Tip: Remember that fats provide more energy gram-for-gram than carbohydrates, but excess fat consumption causes obesity.

Q4. Why should we not eat unknown plants round us even it seem to be edible to us?
Answer: We should not eat unknown plants because many plants in nature contain toxic or poisonous chemicals that can cause severe illness, vomiting, organ failure, or even death. Appearance can be deceptive, as poisonous plants often look harmless or similar to edible varieties.
In simple words: Unknown plants might be poisonous and harmful to our health.

Exam Tip: Never consume wild or unfamiliar berries, leaves, or roots without expert confirmation of safety.

Q5. Why should we try to prevent wastage of food?
Answer: We should prevent the wastage of food because a large number of people in our country and around the world do not get even one full square meal a day and suffer from severe hunger and malnutrition. Furthermore, growing, harvesting, and transporting food requires enormous amounts of water, energy, and labor.
In simple words: Preventing food wastage ensures food reaches the needy and conserves precious Earth resources.

Exam Tip: Link food conservation with global hunger and resource management for complete answers.

Q6. Do you feel that food is essential before going to bed?
Answer: No, heavy food is not essential or recommended immediately before going to bed. While our body needs a constant supply of energy for basic metabolic processes during sleep, eating a heavy meal right before sleeping can lead to indigestion, acidity, and disturbed sleep. Dinner should be light and eaten at least two hours before bedtime.
In simple words: Eating heavy meals right before sleep causes indigestion; light dinner a few hours prior is best.

Exam Tip: Maintain a healthy time gap between dinner and bedtime to avoid digestive discomfort.

Q7. Differentiate between carnivores and omnivores.
Answer:
1. Carnivores: Animals that eat only the flesh of other animals are called carnivores (e.g., lion, tiger).
2. Omnivores: Animals that eat both plants and plant products as well as flesh of other animals are called omnivores (e.g., bear, human being, crow).
In simple words: Carnivores eat only meat, while omnivores eat both plants and meat.

Exam Tip: Always provide clear examples when differentiating animal feeding habits.

Q8. What is the difference between edible and non edible parts of the plants?
Answer:
1. Edible parts: Those parts of a plant that are safe and fit for human consumption (e.g., fruits, vegetables, seeds, leaves of spinach) are called edible parts.
2. Non-edible parts: Those parts of a plant that cannot be eaten by humans because they are hard, tasteless, indigestible, or poisonous (e.g., wood, bark, thorns, certain roots) are called non-edible parts.
In simple words: Edible parts can be safely eaten as food, while non-edible parts cannot.

Exam Tip: Cite specific examples like spinach leaves (edible) versus plant bark (non-edible).

Q9. Write an activity to show that saliva acts on starch.
Answer:
Aim: To show the action of saliva on starch.
Materials required: Two test tubes (labeled A and B), boiled rice/starch solution, and iodine solution.
Procedure:
1. Take one teaspoon of boiled rice in test tube A and keep it in your mouth, chewing it for 3 to 5 minutes so it mixes thoroughly with saliva.
2. Take another teaspoon of boiled rice directly into test tube B without chewing.
3. Add a few drops of iodine solution to both test tubes A and B.
Observation: Test tube B turns blue-black, indicating the presence of starch. Test tube A does not show any blue-black color change.
Conclusion: Saliva breaks down starch into simple sugars (maltose), which do not give a blue-black test with iodine.
In simple words: Chewed food mixed with saliva loses its starch property because saliva converts starch into sugar.

Exam Tip: Mention the iodine test color change (blue-black for starch, no change when starch is digested) clearly.

Q10. Write a short note on the importance of proteins in our body and explain the effects of eating food deficient of proteins.
Answer:
Importance of proteins: Proteins are known as bodybuilding foods. They are essential for the growth, repair, and maintenance of body tissues, muscles, organs, skin, and hair, as well as for making enzymes and hormones.
Effects of protein deficiency: A diet deficient in proteins for a long time can lead to stunted growth, discoloration of hair, skin diseases, swelling of the face (especially edema), diarrhea, and a severe disease known as kwashiorkor, characterized by a swollen belly and thin limbs.
In simple words: Proteins build our body, and lacking them leads to weak muscles, stunted growth, and diseases like kwashiorkor.

Exam Tip: Keywords like 'bodybuilding foods' and 'kwashiorkor' are essential for scoring full marks.

Q11. Have you ever observed your mother not washing rice and pulses repeatedly? Find out the reason.
Answer: Yes, rice and pulses should not be washed repeatedly because repeated washing washes away vital water-soluble vitamins (such as Vitamin B group) and essential minerals present on their outer layers, along with reducing their nutritive value.
In simple words: Washing rice and pulses too many times removes important vitamins and minerals.

Exam Tip: Emphasize the loss of water-soluble vitamins and nutrients due to over-washing.

Q12. A table given below in which names of the animals have been given and food they eat are in blank space. Fill the blank spaces.
Answer: Completed table of animal feeding habits:

In simple words: Animals eat different types of food depending on whether they are herbivores, carnivores, or omnivores.
Exam Tip: Be precise with dietary classifications (herbivore, carnivore, omnivore) when filling out animal food tables.