All algae contain:

Options

A. chlorophyll a and chlorophyll b
B. chlorophyll b and carotenes
C. chlorophyll a and carotenes
D. phycobilins and carotenes

Explanation

To answer the question "All algae contain:", we need to analyze the types of pigments found in algae. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Types of Algae
Algae are a diverse group of photosynthetic organisms that can be classified into different categories, such as green algae, brown algae, red algae, and others.

### Step 2: Understand the Pigments in Algae
Algae contain various pigments that are crucial for photosynthesis. The primary pigments include:
- **Chlorophyll-a**: This is the main pigment found in all algae.
- **Chlorophyll-b**: Found in green algae.
- **Carotenoids**: These are accessory pigments present in many algae.

### Step 3: Analyze the Options
Now, let’s analyze the options provided in the question:
1. Chlorophyll-a
2. Chlorophyll-b
3. Chlorophyll-b and carotenoids
4. Chlorophyll-a and carotenes
5. Psychoglens and carotenes

From the analysis, we know that:
- **Chlorophyll-a** is present in all algae.
- **Chlorophyll-b** is present in some algae, but not all.
- **Carotenoids** are also common but not universal.

### Step 4: Determine the Correct Answer
Since the question asks for pigments that are present in **all** algae, the correct answer is **Chlorophyll-a**.

### Final Answer
**All algae contain Chlorophyll-a.**

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