megagametophyte

American  

[meg-uh-guh-mee-tuh-fahyt] / ˌmɛg ə gəˈmi təˌfaɪt /

noun

Botany.

1. the female gametophyte in seed plants.

---

megagametophyte Scientific  

/ mĕg′ə-gə-mē′tə-fīt′ /

1. The female gametophyte that develops from the megaspores of heterosporous plants. Among heterosporous species of the lycophyte plants, for example, the sporophyte plant produces megaspores stocked with food. These spores grow into megagametophytes that produce eggs. After fertilization of the eggs, the embryos grow into new sporophytes inside the megagametophyte and are nourished by the food within it. In the seed plants, the megagametophyte generation is very small and lives its entire existence within the ovules of the sporophyte plant, where some of its cells become eggs, while others become food reserves for the resultant embryos.

2. See more at alternation of generations gametophyte

---

Other Word Forms

• megagametophytic adjective

Etymology

Origin of megagametophyte

First recorded in 1930–35; mega- + gametophyte

Example Sentences

During the second phase, megagametogenesis, the surviving haploid megaspore undergoes mitosis to produce an eight-nucleate, seven-cell female gametophyte, also known as the megagametophyte or embryo sac.

From Textbooks • Jan. 1, 2015

Together, these cells are called the megagametophyte, or embryo sac.

From Textbooks • Jan. 1, 2015

Both microspores and megaspores undergo mitosis, forming the microgametophyte and megagametophyte, respectively.

From Textbooks • Jan. 1, 2015

Illustration shows the life cycle of angiosperms, which includes a microgametophyte stage and a megagametophyte stage.

From Textbooks • Jan. 1, 2015