In Funaria, 20 chromosomes are present in rhizoids, then the umber of chromosome in calyptra, theca and foot will be

Options

A. 20 , 40 , 40 , respectively
B. 40 , 20 , 20 respectively
C. 20 , 40 , 20 respectively
D. 40 , 10 , 20 respectively

Answer

To solve the problem regarding the number of chromosomes in Funaria, we need to understand the basic concepts of its life cycle and structure. Here’s a step-by-step breakdown:

### Step 1: Identify the Chromosome Count in Rhizoids
- Funaria is a bryophyte, and in this organism, the rhizoids are haploid structures.
- The question states that there are 20 chromosomes present in the rhizoids.

**Hint:** Remember that rhizoids are part of the gametophyte generation, which is haploid (n).

### Step 2: Determine the Chromosome Count in the Gametophyte
- Since the rhizoids are haploid and contain 20 chromosomes, the gametophyte (the main plant body of bryophytes) will also be haploid and have the same number of chromosomes, which is 20.

**Hint:** The gametophyte generation is always haploid in bryophytes.

### Step 3: Understand the Sporophyte Generation
- The sporophyte generation in bryophytes is diploid (2n). It consists of structures such as the foot, seta, and capsule.
- Since the gametophyte has 20 chromosomes (n = 20), the sporophyte will have double that number.

**Hint:** The sporophyte generation is formed from the fusion of gametes and is diploid.

### Step 4: Calculate the Chromosome Count in the Sporophyte Structures
- If n = 20 for the gametophyte, then for the sporophyte (2n), we have:
- 2n = 40 chromosomes.
- Therefore, the foot, seta, and capsule of the sporophyte will each have 40 chromosomes.

**Hint:** The foot, seta, and capsule are all parts of the diploid sporophyte.

### Step 5: Summarize the Chromosome Counts
- Rhizoids: 20 chromosomes (haploid)
- Calyptra: 20 chromosomes (haploid, as it is part of the gametophyte)
- Theca: 40 chromosomes (diploid, part of the sporophyte)
- Foot: 40 chromosomes (diploid, part of the sporophyte)

### Final Answer
- The number of chromosomes in Funaria is:
- Rhizoids: 20
- Calyptra: 20
- Theca: 40
- Foot: 40

Thus, the answer is:
- Rhizoids: 20
- Calyptra: 20
- Theca: 40
- Foot: 40