Which of the following statements regarding kingdom Animalia is incorrect?

Options

A. It includes heterotrophic, unicellular eukaryotic organisms.
B. The members of this kingdom lack cell walls.
C. The mode of nutrition is holozoic.
D. The sexual reproduction in its members is by copulation of male and female.

Explanation

To determine which statement regarding kingdom Animalia is incorrect, we can analyze each of the provided statements step by step.

### Step 1: Analyze the statements
1. **Statement 1**: It includes the heterotrophic unicellular eukaryotic organisms.
2. **Statement 2**: The members of its kingdom lack cell walls.
3. **Statement 3**: The mode of nutrition is holozoic.
4. **Statement 4**: The sexual reproduction in its members is called by copulation of male and female.

### Step 2: Evaluate each statement
- **Statement 1**: This statement claims that kingdom Animalia includes heterotrophic unicellular eukaryotic organisms. However, kingdom Animalia does not include unicellular organisms; it primarily consists of multicellular organisms. Unicellular eukaryotic organisms are classified under the kingdom Protista. Therefore, this statement is **incorrect**.

- **Statement 2**: Members of kingdom Animalia do lack cell walls. This is true, as animal cells are characterized by their lack of rigid cell walls, unlike plant cells. Therefore, this statement is **correct**.

- **Statement 3**: The mode of nutrition in kingdom Animalia is indeed holozoic, which means they ingest solid food. This statement is also **correct**.

- **Statement 4**: Sexual reproduction in animals typically involves copulation between male and female. This statement is **correct**.

### Step 3: Conclusion
After evaluating all the statements, we conclude that the **incorrect statement** regarding kingdom Animalia is **Statement 1**: "It includes the heterotrophic unicellular eukaryotic organisms."

### Final Answer
The incorrect statement regarding kingdom Animalia is: **It includes the heterotrophic unicellular eukaryotic organisms.**

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