Which layer in Arceuthobium has fibrous thickening and it is called?

Options

A. Exothecium
B. Endothecium
C. Middle layer
D. Tapetum

Answer

To solve the question "Which layer in Arceuthobium has fibrous thickening and it is called?", we can follow these steps:

### Step 1: Understand the Structure of Arceuthobium
Arceuthobium is a genus of parasitic plants, and its anther structure is similar to that of other flowering plants. The anther consists of several layers.

**Hint:** Familiarize yourself with the basic structure of anther in flowering plants.

### Step 2: Identify the Layers of the Anther
The anther has several layers:
- Epidermis (outermost layer)
- Endothecium (inner to epidermis)
- Middle layers
- Tapetum (innermost layer)

**Hint:** Recall the order of layers in a typical anther structure.

### Step 3: Focus on the Epidermis Layer
In Arceuthobium, the epidermis is noted to be thick-walled compared to other plants. This thickening is due to the presence of fibrous bands.

**Hint:** Consider how the epidermis might differ in structure in various plant species.

### Step 4: Identify the Specific Thickening
The thickening in the epidermis of Arceuthobium is specifically referred to as "Exothicium". This layer has fibrous thickening due to the presence of alpha-cellulosic fibrous bands.

**Hint:** Think about the terminology used in botany to describe plant structures.

### Step 5: Conclusion
Based on the information gathered, the layer in Arceuthobium that has fibrous thickening is called the "Exothicium".

**Final Answer:** The Exothicium in Arceuthobium has fibrous thickening and it is called Exothicium.