Ch 2 covers the process of nutrition in animals, focusing on the human digestive system. Students learn the five steps of nutrition and how digestion works differently in ruminants and amoeba.
Ingestion: taking food into the mouth. Digestion: breaking down complex food into simple substances. Absorption: nutrients pass into blood through intestinal wall. Assimilation: cells use nutrients for energy and growth. Egestion: removal of undigested waste.
Mouth (teeth chew, saliva breaks starch) → Oesophagus (food pipe, peristalsis) → Stomach (HCl + pepsin digest proteins) → Small intestine (bile + pancreatic juice complete digestion; villi absorb nutrients) → Large intestine (absorbs water) → Anus (egestion).
Ruminants (cow, buffalo) have a four-chambered stomach. They swallow food, bring it back (cud), rechew, and digest cellulose with bacteria. Amoeba uses pseudopodia to engulf food (phagocytosis) and digests it in a food vacuole.
Download: https://ncert.nic.in/textbook/pdf/gesc102.pdf | Complete book: https://ncert.nic.in/textbook/pdf/gesc1ps.zip
Chewing breaks food into smaller pieces, increasing the surface area for digestive enzymes to act on. Saliva mixes with food and begins starch digestion. Thorough chewing makes the entire digestion process faster and more efficient.
Book a Trial + Diagnostic session. Get a personalized Learning Path with clear milestones, tutor match, and a plan recommendation — all within 24 hours.
Book Trial + Diagnostic →