Whittaker's system of classification implies that unicellular eukaryotes are primarily precursors of the

Options

A. (a) plants
B. (b) fungi
C. (c) animals
D. (d) all of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Whittaker's Classification**: Whittaker's system of classification divides living organisms into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia. Unicellular eukaryotes are categorized under the Kingdom Protista.

2. **Identifying Unicellular Eukaryotes**: Unicellular eukaryotes, also known as protists, include organisms that are primarily single-celled and have a complex cellular structure with a nucleus.

3. **Categories of Protists**: In Whittaker's classification, protists are further divided into three main categories based on their characteristics:
- **Protozoans**: These are animal-like protists that are heterotrophic (they consume organic material for food) and have the ability to move. They are considered to be the precursors of the Animal Kingdom.
- **Algae**: These are plant-like protists that are autotrophic (they can produce their own food through photosynthesis). Algae are thought to be the precursors of the Plant Kingdom.
- **Molds**: These are fungus-like protists that are saprotrophic (they feed on dead and decaying matter) and reproduce via spores. They are considered to be the precursors of the Fungal Kingdom.

4. **Conclusion**: Since unicellular eukaryotes (protists) give rise to all three kingdoms (Animals, Plants, and Fungi), the correct answer to the question is that they are the precursors of all of the above.

5. **Final Answer**: Therefore, the answer is D. All of the above.

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