Define biology, explain two types of digestion, and identify reasons an organism is a plant or animal using a food chain.

Here are the answers to the biology questions:

Section B (50 marks)

21a. Define the term biology.
Biology is the scientific study of living organisms, including their structure, function, growth, origin, evolution, and distribution.

21b. Explain any two types of digestion.

• Physical digestion (or mechanical digestion): The physical breakdown of food into smaller pieces, such as chewing in the mouth or churning in the stomach, without chemical changes.
• Chemical digestion: The breakdown of complex food molecules into simpler, soluble molecules by the action of enzymes, occurring in the mouth, stomach, and small intestine.

21c. The diagram below is an organism use it to answer questions that follows. (Food chain: grass $\rightarrow$ grasshopper $\rightarrow$ birds)

21c.i. Explain the reason the organism is an animal.
An organism is an animal if it is a heterotroph, meaning it obtains nutrients by consuming other organisms. Animals typically move and lack cell walls.

21c.ii. Explain the reason the organism is a plant.
An organism is a plant if it is an autotroph, meaning it produces its own food through photosynthesis using sunlight, water, and carbon dioxide. Plants contain chlorophyll and have cell walls.

21c.iii. From the experiment students concluded that chlorophyll is necessary for photosynthesis. Explain if the conclusion was right.
Yes, the conclusion is right. Chlorophyll is the green pigment in plants that absorbs light energy from the sun, which is essential for converting carbon dioxide and water into glucose (food) during photosynthesis. Without chlorophyll, photosynthesis cannot occur.

21c.iv. To what group of animals do the following belongs

• Octopus: Mollusca
• Frogs: Amphibia

22a. what is digestion.
Digestion is the process of breaking down complex food substances into simpler, soluble forms that can be absorbed and utilized by the body.

22b. list any two examples of the following types of digestions
Assuming this refers to examples of where physical and chemical digestion occur:

• Physical digestion: Occurs in the mouth (chewing) and stomach (churning).
• Chemical digestion: Occurs in the stomach (by pepsin) and small intestine (by various enzymes).