Feature Ruminant Non-ruminant Number of stomach compartments 4 1 Cellulose digestion Yes Very limited Microorganisms in stomach Present in large numbers Abs...

(a) The animal with a four-chambered stomach is the ruminant. [1] The four compartments are the rumen, reticulum, omasum and abomasum.

(b) Examples: [2]

• Ruminant farm animal: cow (also acceptable: sheep, goat). [1]
• Non-ruminant farm animal: pig (also acceptable: chicken). [1]

(c) Why ruminants can digest cellulose but non-ruminants cannot do so efficiently: [4]

1. Ruminants harbour large populations of microorganisms (bacteria and protozoa) in their rumen. [1]
2. These microorganisms produce cellulase enzymes that break down cellulose, which the animal's own digestive enzymes cannot do. [1]
3. The fermentation of cellulose by these microorganisms produces volatile fatty acids (VFAs), which are absorbed through the rumen wall into the bloodstream and used as the animal's main energy source. [1]
4. Non-ruminants have a simple, single-chambered stomach that lacks these cellulose-digesting microorganisms, so they cannot break down cellulose efficiently. [1]

The table confirms this: ruminants have microorganisms "present in large numbers" while non-ruminants have them "absent or very few."

(d) Advantage of keeping ruminant livestock on poor-quality grazing land: [1]

Ruminants can convert low-quality forage, rough grass and fibrous plant material into useful products such as milk and meat. [1] This means land that would be unsuitable for growing crops can still be used productively.

(e) Role of bile in digestion (applies to both ruminants and non-ruminants): [2]

• Bile is produced by the liver and stored in the gall bladder. [1]
• It emulsifies fats: it breaks large fat globules into much smaller droplets, greatly increasing the surface area available for the enzyme lipase to act upon. This speeds up fat digestion. [1]