How many of the following statements are incorrect ?
(i) The shape of the cell may vary with the function they perform.
(ii) Nerve cells are some of the longest cells.
(iii) The largest isolated single cell is the egg of an ostrich.
(iv) Blue-green algae are eukaryotes.
(v) Prokaryotic cells are generally smaller and multiply slowly than eukaryotic cells.

Options

A. Two
B. Four
C. Three
D. Five

Answer

To determine how many of the provided statements are incorrect, we will analyze each statement one by one.

**Step 1: Analyze each statement**

1. **Statement (i):** The shape of the cell may vary with the function they perform.
- **Analysis:** This statement is correct. Cells have different shapes depending on their functions. For example, red blood cells are biconcave to facilitate oxygen transport.

2. **Statement (ii):** Nerve cells are some of the longest cells.
- **Analysis:** This statement is also correct. Nerve cells, or neurons, can be very long, with some extending several feet in length.

3. **Statement (iii):** The largest isolated single cell is the egg of an ostrich.
- **Analysis:** This statement is correct. The ostrich egg is indeed the largest single cell known, weighing about 1.5 kg.

4. **Statement (iv):** Blue-green algae are eukaryotes.
- **Analysis:** This statement is incorrect. Blue-green algae, also known as cyanobacteria, are prokaryotic organisms, meaning they lack a membrane-bound nucleus and organelles.

5. **Statement (v):** Prokaryotic cells are generally smaller and multiply slowly than eukaryotic cells.
- **Analysis:** This statement is incorrect. While prokaryotic cells are generally smaller than eukaryotic cells, they actually multiply faster than eukaryotic cells through a process called binary fission.

**Step 2: Count the incorrect statements**
- From the analysis:
- Statement (iv) is incorrect.
- Statement (v) is incorrect.

Thus, there are **2 incorrect statements**.

**Final Answer:** 2 statements are incorrect.

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