Arrange the following in descending order
(a) Number of bivalents formed during meiosis of a spore mother of Ophioglossum
(b) Number of chromatids seen on equator at metaphase I in pollen mother cell of Haplopappus gracilis during meiosis
(c ) Number of chromosomes found at one pole after anaphase II during meiosis in butterfly
(d) Total number of chromosomes found in all daughter cells formed during meiosis from one megaspore mother cell in Potato

Options

A. b,d,c,a
B. a,c,d,b
C. a,d,c,b
D. d,c,b,a

Answer

To solve the problem, we need to analyze each option and determine the numerical values associated with them. Then we can arrange these values in descending order.

### Step-by-Step Solution:

1. **Identify the number of bivalents formed during meiosis of a spore mother cell of Ophioglossum:**
- Ophioglossum is known to have a diploid chromosome number of 1260.
- The number of bivalents formed during meiosis is half the total number of chromosomes.
- Therefore, the number of bivalents = 1260 / 2 = **630**.

2. **Determine the number of chromatids seen on the equator at metaphase I in the pollen mother cell of Haplopappus gracilis:**
- The diploid number (2n) for Haplopappus gracilis is given as 4.
- Thus, the number of chromosomes at metaphase I is 4, which means there are 8 chromatids (since each chromosome is replicated).
- Therefore, the number of chromatids = **8**.

3. **Find the number of chromosomes found at one pole after anaphase II during meiosis in butterflies:**
- Butterflies have a diploid chromosome number of 380.
- After anaphase II, the number of chromosomes at one pole will be half of the diploid number.
- Therefore, the number of chromosomes at one pole = 380 / 2 = **190**.

4. **Calculate the total number of chromosomes found in all daughter cells formed during meiosis from one megaspore mother cell in Potato:**
- The diploid chromosome number for potato is 48.
- During meiosis, one megaspore mother cell produces 4 daughter cells.
- Each daughter cell will have half the diploid number, which is 48 / 2 = 24.
- Therefore, the total number of chromosomes in all daughter cells = 4 * 24 = **96**.

### Summary of Values:
- (a) Ophioglossum: 630 bivalents
- (b) Haplopappus gracilis: 8 chromatids
- (c) Butterfly: 190 chromosomes at one pole
- (d) Potato: 96 total chromosomes in daughter cells

### Arranging in Descending Order:
1. Ophioglossum: **630**
2. Butterfly: **190**
3. Potato: **96**
4. Haplopappus gracilis: **8**

Thus, the correct descending order is:
**(a) > (c) > (d) > (b)**

### Final Answer:
The correct arrangement in descending order is: **(a), (c), (d), (b)**.

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