Which of the following plant cycles is exhibited by Ectocarpus and kelps ?

Options

A. Diplontic
B. Haplontic
C. Haplo-diplontic cycle
D. None of the above

Answer

To solve the question regarding the plant cycles exhibited by Ectocarpus and kelps, we can follow these steps:

### Step 1: Identify the Organisms
Ectocarpus and kelps are both types of brown algae. Understanding their classification is essential for determining their life cycles.

**Hint:** Remember that Ectocarpus is a genus of brown algae, while kelps are large brown algae that belong to the order Laminariales.

### Step 2: Understand the Life Cycle Types
In plants, there are different life cycle patterns, primarily:
- **Haploid (n)**: The organism has one set of chromosomes.
- **Diploid (2n)**: The organism has two sets of chromosomes.
- **Haplodiplontic (or alternation of generations)**: This involves both haploid and diploid multicellular stages.

**Hint:** Familiarize yourself with the terms haploid, diploid, and haplodiplontic as they are crucial for understanding plant life cycles.

### Step 3: Analyze the Life Cycle of Ectocarpus and Kelps
Both Ectocarpus and kelps exhibit a haplodiplontic life cycle, which involves an alternation of generations between multicellular haploid (gametophyte) and multicellular diploid (sporophyte) stages.

**Hint:** Look for the terms gametophyte (haploid stage) and sporophyte (diploid stage) when discussing plant life cycles.

### Step 4: Confirm the Characteristics of the Life Cycle
In the haplodiplontic cycle:
- The sporophyte generation is diploid and produces spores through meiosis.
- The gametophyte generation is haploid and produces gametes through mitosis.

**Hint:** Remember that the presence of both multicellular stages is a key feature of the haplodiplontic life cycle.

### Step 5: Conclusion
Based on the analysis, we can conclude that both Ectocarpus and kelps exhibit the haplodiplontic life cycle.

**Final Answer:** The correct answer is the haplodiplontic cycle.