In which one of the following plants sporophyte is completely dependent on gametophyte ?

Options

A. Riccia
B. Funaria
C. Angiosperms
D. Gymnosperms

Explanation

To determine which plant has a sporophyte that is completely dependent on the gametophyte, we can follow these steps:

### Step 1: Understand the Life Cycle of Plants
- In plants, there are two main phases: the gametophyte phase and the sporophyte phase. The gametophyte is the haploid stage that produces gametes, while the sporophyte is the diploid stage that produces spores.

### Step 2: Identify the Characteristics of Bryophytes
- Bryophytes (which include mosses, liverworts, and hornworts) are known for having a dominant gametophyte stage. In these plants, the sporophyte is often dependent on the gametophyte for nutrition.

### Step 3: Analyze the Options Given
- The options provided are:
1. Rixia
2. Funaria
3. Angiosperms
4. Gymnosperms

### Step 4: Evaluate Each Option
- **Angiosperms and Gymnosperms**: These groups have a dominant sporophyte phase and are not dependent on gametophytes, so they can be eliminated.

- **Funaria**: In Funaria (a type of moss), the sporophyte is partially dependent on the gametophyte for water and minerals, but it can manufacture its own food. Thus, it does not meet the criteria of being completely dependent.

- **Rixia**: In Rixia, the sporophyte is entirely dependent on the gametophyte. The sporophyte is simple and consists mainly of a spore case (capsule) that contains spores. This indicates complete dependency on the gametophyte.

### Step 5: Conclusion
- Based on the analysis, the correct answer is **Rixia**, as its sporophyte is completely dependent on the gametophyte.

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