Silphoning is not a recognized term in the context of Chapter 2: Nutrition in Animals in the Class 7 Science curriculum. It is possible that you may have misspelled or misinterpreted the term. However, in this chapter, there are several important concepts related to nutrition in animals that are worth exploring.

1. Nutrition in Animals:
- Animals require nutrients for their growth, development, and maintenance of bodily functions.
- They obtain these nutrients by consuming food, which can be categorized as herbivores, carnivores, or omnivores based on their dietary preferences.

2. Modes of Feeding:
- Different animals have adapted various modes of feeding to obtain food.
- Herbivores primarily feed on plants, carnivores consume other animals, and omnivores have a mixed diet of both plants and animals.

3. Digestion in Animals:
- Animals have specialized digestive systems that help them break down food into simpler substances for absorption and utilization.
- The process of digestion involves mechanical and chemical breakdown of food.

4. Human Digestive System:
- The human digestive system consists of various organs, including the mouth, esophagus, stomach, small intestine, large intestine, and rectum.
- Each organ performs specific functions in the digestion and absorption of nutrients.

5. Digestive Enzymes:
- Digestive enzymes play a crucial role in the digestion process by breaking down complex molecules into simpler forms.
- Examples of digestive enzymes include amylase (breaks down carbohydrates), protease (breaks down proteins), and lipase (breaks down fats).

6. Nutrient Absorption:
- After digestion, the nutrients are absorbed into the bloodstream through the walls of the small intestine.
- The absorbed nutrients are then transported to various cells and tissues in the body for energy production and growth.

7. Assimilation and Egestion:
- Assimilation refers to the utilization of absorbed nutrients by the body for various metabolic processes.
- Egestion is the elimination of undigested food materials as feces through the rectum and anus.

In conclusion, while the term "silphoning" does not have any relevance in the context of Chapter 2: Nutrition in Animals, it is important to understand the concepts of nutrition, digestion, absorption, and assimilation in animals to grasp the fundamentals of this chapter.