Following components are haploid, diploid or triploid (A) oosphere (B) microsphere (C ) sunergids (D) antipodals (E ) oospore (F) nucellus (G) placenta (chalaza) (I) endosperm (J) tapetum
Which of following groups show the correct sequence of the ascending order of ploidy in ovule/seed ?

Options

A. C,B,D
B. A,E,I
C. E,F,G
D. J,E,H

Answer

To determine the correct sequence of ascending order of ploidy in the components of an ovule/seed, we first need to classify each component as haploid (1n), diploid (2n), or triploid (3n). Here’s the breakdown:

1. **Oosphere (A)**: This is the female gamete in plants and is haploid (1n).

2. **Microsphere (B)**: This term is not commonly used in standard plant biology; it may refer to a microspore, which is also haploid (1n).

3. **Synergids (C)**: These are two cells that accompany the egg cell in the embryo sac and are haploid (1n).

4. **Antipodals (D)**: These are three cells located at the opposite end of the embryo sac and are also haploid (1n).

5. **Oospore (E)**: This is formed after fertilization when the oosphere is fertilized by a male gamete, resulting in a diploid (2n) structure.

6. **Nucellus (F)**: This is the central part of the ovule and is diploid (2n).

7. **Placenta (G)**: This is the tissue to which the ovules are attached and is also diploid (2n).

8. **Endosperm (H)**: This is formed after fertilization when two polar nuclei fuse with a male gamete, resulting in a triploid (3n) structure.

9. **Tapetum (I)**: This is the layer of cells that provides nourishment to the developing pollen grains and is diploid (2n).

Now, we can summarize the ploidy levels for each component:
- A (Oosphere) - Haploid (1n)
- B (Microsphere) - Haploid (1n)
- C (Synergids) - Haploid (1n)
- D (Antipodals) - Haploid (1n)
- E (Oospore) - Diploid (2n)
- F (Nucellus) - Diploid (2n)
- G (Placenta) - Diploid (2n)
- H (Endosperm) - Triploid (3n)
- I (Tapetum) - Diploid (2n)

Now, we can arrange these components in ascending order of ploidy:
1. Oosphere (A) - 1n
2. Microsphere (B) - 1n
3. Synergids (C) - 1n
4. Antipodals (D) - 1n
5. Oospore (E) - 2n
6. Nucellus (F) - 2n
7. Placenta (G) - 2n
8. Tapetum (I) - 2n
9. Endosperm (H) - 3n

From the above, the correct sequence of ascending order of ploidy in ovule/seed is:
- A (Oosphere) → E (Oospore) → H (Endosperm)

Thus, the correct option is **B: A, E, I**.