Tuesday, May 13, 2025

GRADE -7 Science HH

 

S. D. INTERNATIONAL SCHOOL

SUMMER HOLIDAYS HOMEWORK

GRADE -7 Science  

 

1.     The assignment is to be documented in the science notebook

2.      Chapters 1, 2, and 3 require careful revision to grasp the key concepts.

3.      Assignment chapter 2 “ Nutrition in animals”

Q 1: Rohan observed that his pet cow was chewing continuously even when it was not eating. Why do cows do that? What does this indicate about their digestive system?

Q 2: If the salivary glands stop functioning, how will it affect the digestion of food? Explain with reasons.

Q 3: A student examined a sample of food under a microscope and saw amoebas surrounding it with pseudopodia. What process was being observed? What does it tell us about the nutrition in amoeba?

Q 4: How is the process of digestion in a ruminant animal different from that in humans? Mention any two differences.

Q 5: Amit complains of indigestion and stomach pain after eating very quickly. What habits should he change, and why?

Q 6: Draw the diagram of the human digestive system. Label the following parts:

Mouth               Stomach            Small intestine               Large intestine
Also mention the function of any one of these parts.

Q 7: Why should we not lie down immediately after eating a heavy meal? Relate your answer to the process of digestion.

Q8: Why does food take longer to digest in the stomach than in the mouth? What advantages does this provide to the body?

Q9: Explain how the nutrients absorbed in the small intestine reach different parts of the body. Which system is involved apart from the digestive system?

 High Order Thinking Skill Assignment :

Chapter 1 Nutrition in Plants –

1.      Imagine a plant placed in a sealed transparent container with ample sunlight but no carbon dioxide. Predict and explain what will happen to the plant over a week.

  1. If you were a Rhizobium bacterium living in the root nodules of a leguminous plant, describe your daily activities and how you benefit the plant.
  2. Propose an experiment to demonstrate that chlorophyll is essential for photosynthesis. What controls would you include?
  3. Compare and contrast the modes of nutrition in a pitcher plant and a mushroom. How do their nutritional strategies adapt them to their environments?
  4. Why are farmers advised to grow leguminous crops in rotation with other crops? Discuss the underlying biological processes involved.
  5. Imagine you're a detective investigating a case where a plant isn't thriving despite adequate sunlight and water. What could be the possible reasons? Consider factors like chlorophyll presence, carbon dioxide levels, and nutrient availability.
  6. Suppose scientists discover a new planet species on Mars that doesn't perform photosynthesis but thrives in low-light conditions. How might this plant obtain its nutrition? Propose a possible mode of nutrition and justify your reasoning.

8.      You're transported back to a time before plants evolved chlorophyll. How did early plant-like organisms obtain energy? Discuss the evolution of autotrophic nutrition.

  1. Write a diary entry from the perspective of a leaf detailing a day in the life of photosynthesis, including interactions with sunlight, water, and carbon dioxide.
  2. As an agricultural scientist, design a soil composition that would maximize plant growth without synthetic fertilizers. What natural components would you include, and why

Chapter 2 :Nutrition in Animals

1.      Trace the journey of a morsel of bread through the human digestive system, highlighting the role of enzymes at each stage.

  1. Describe the process of nutrition in an amoeba from the organism's point of view. How does it locate and digest its food?
  2. Explain why cows chew cud. What advantages does this behavior provide in terms of digestion and nutrient absorption?
  3. Design an activity to show the effect of saliva on starch. What observations would confirm the action of salivary amylase?
  4. Conduct an experiment to map the taste regions of the human tongue. How would you test for sweet, salty, sour, and bitter tastes?

Or

Create a map of the human tongue indicating the regions most sensitive to different tastes. How does this distribution aid in nutrition and survival?

 

  1. If you were to design a digestive system for a new species that consumes both plants and animals, what features would it have? Explain the reasoning behind the length of the intestine, types of teeth, and enzymes present.
  2. Narrate a short story from the perspective of an amoeba hunting for food, capturing it, and digesting it. Highlight the processes involved in its nutrition.
  3. Imagine you're a cow explaining to a non-ruminant friend why you chew cud. Describe the benefits of this process in your own words.
  4. Design an experiment to test the effect of temperature on the activity of salivary amylase. What results would you expect, and why?

 

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