In prokaryotes , mitochodria are absent Krebs cycle occurs over

Options

A. Cytoplasm
B. Nucleoid
C. Ribosome
D. Plasma membrane.

Answer

To answer the question, "In prokaryotes, mitochondria are absent; Krebs cycle occurs over," we will follow these steps:

### Step 1: Understand the absence of mitochondria in prokaryotes
Prokaryotes, which include bacteria and archaea, do not have membrane-bound organelles, including mitochondria. This is a key characteristic that distinguishes them from eukaryotic cells.

**Hint:** Remember that prokaryotes lack membrane-bound organelles.

### Step 2: Identify where the Krebs cycle occurs in eukaryotes
In eukaryotic cells, the Krebs cycle (also known as the citric acid cycle) occurs in the mitochondria, which is often referred to as the powerhouse of the cell.

**Hint:** Recall that in eukaryotes, the Krebs cycle is linked to mitochondria.

### Step 3: Determine the alternative location for the Krebs cycle in prokaryotes
Since prokaryotes do not have mitochondria, the Krebs cycle must occur in a different location. In prokaryotes, the Krebs cycle takes place in the cytoplasm. However, there are structures called mesosomes, which are invaginations of the plasma membrane that can also be involved in cellular respiration processes.

**Hint:** Consider the role of the plasma membrane and any special structures in prokaryotes.

### Step 4: Analyze the options provided
The options given are:
1. Cytoplasm
2. Nucleoid
3. Ribosome
4. Plasma membrane

Since the Krebs cycle occurs in the cytoplasm of prokaryotes, but specifically in the mesosomes (which are invaginations of the plasma membrane), the most accurate answer is the plasma membrane.

**Hint:** Focus on the fact that mesosomes are part of the plasma membrane.

### Step 5: Select the correct answer
Based on the analysis, the correct answer to the question is option 4: Plasma membrane.

**Final Answer:** The Krebs cycle occurs in the plasma membrane (specifically in the mesosomes) in prokaryotes.