A tetraploid male plant crosses with a hexaploid female plant, find out the ploidy level of embryo and endosperm

Options

A. Pentaploid and octaploid
B. Heptaploid and pentaploid
C. Diploid and triploid
D. Haploid and diploid

Answer

To solve the problem of determining the ploidy level of the embryo and endosperm resulting from the cross between a tetraploid male plant and a hexaploid female plant, we can follow these steps:

### Step 1: Identify the Ploidy Levels of the Parent Plants
- The male plant is tetraploid, which means it has 4 sets of chromosomes (4N).
- The female plant is hexaploid, which means it has 6 sets of chromosomes (6N).

### Step 2: Determine the Ploidy Level of Gametes
- Gametes are produced through meiosis, which reduces the ploidy level by half.
- Therefore, the male gamete will have a ploidy level of 2N (4N/2).
- The female gamete will have a ploidy level of 3N (6N/2).

### Step 3: Formation of the Embryo
- The embryo is formed from the fertilization of the egg cell (female gamete) by the male gamete.
- The egg cell has a ploidy level of 3N, and the male gamete has a ploidy level of 2N.
- When these two gametes fuse, the resulting embryo will have a ploidy level of 5N (3N + 2N).

### Step 4: Formation of the Endosperm
- The endosperm is formed through a process called double fertilization.
- In this process, one male gamete fuses with the egg cell to form the embryo, and another male gamete fuses with the two polar nuclei in the central cell of the female gametophyte.
- The polar nuclei are derived from the megasporangium and have a ploidy level of 3N (2 polar nuclei).
- When the second male gamete (2N) fuses with the polar nuclei (3N), the resulting endosperm will have a ploidy level of 5N (3N + 2N).

### Conclusion
- The ploidy level of the embryo is 5N (pentaploid).
- The ploidy level of the endosperm is 5N (pentaploid).

### Final Answer
- Embryo: 5N (pentaploid)
- Endosperm: 5N (pentaploid)