Inhoudsopgave
Is the megaspore diploid?
A megaspore mother cell, or megasporocyte, is a diploid cell in plants in which meiosis will occur, resulting in the production of four haploid megaspores. At least one of the spores develop into haploid female gametophytes (megagametophytes).
What is haploid megaspore?
The haploid megaspore undergoes three rounds of mitotic divisions that result in eight haploid nuclei contained in seven cells: Two synergids, one egg cell, a central cell with two nuclei, and three antipodals. 5. Double fertilization results in a diploid zygote and a triploid endosperm.
Is megaspore diploid in angiosperms?
In angiosperms, the diploid megaspore mother cell undergoes meiosis to form four haploid megaspores by the process called megasporogenesis. The functional megaspore is the first cell of female gametophyte.
Are Microspores haploid or diploid?
Microspores are haploid, and are produced from diploid microsporocytes by meiosis.
Is Synergid haploid or diploid?
Synergids are the two nuclei in the embryo sac of flowering plants that are closely associated with the oosphere or egg cells, to form the egg apparatus. They are haploid.
Is ovule a megaspore?
The ovule appears to be a megasporangium with integuments surrounding it. Ovules are initially composed of diploid maternal tissue, which includes a megasporocyte (a cell that will undergo meiosis to produce megaspores).
What is a megaspore in angiosperms?
Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which produces egg cells. These are fertilized by sperm produced by the male gametophyte developing from the microspore.
Is megaspore N or 2N?
The megaspore mother cell resides within the ovule that is surrounded by integuments (5) and is attached to the wall of the ovary by the funiculus (3). Again, it is worth restating that all of these cells are part of the sporophyte generation of the plant and that they are diploid (2N).
What is megaspore and microspore?
sporangia; the larger spore (megaspore) gives rise to the female gametophyte, the smaller spore (microspore) to the male. sizes, the larger designated as megaspores and the smaller as microspores. The megaspores develop into female gametophytes and the microspores into male gametophytes.
Is pollen grain diploid or haploid?
Pollen grains mainly represent the male part of the reproductive process in plants and trees. After the formation of the four haploid microspores occurs it fuses to form pollen grain and the development of the pollen grain walls starts. Hence pollen grain is a haploid structure.
Is Synergid haploid or diploid in angiosperms?
Is Chalazal cell haploid?
After meiosis, a single haploid cell, usually the basal (chalazal) cell, will enlarge and form the functional megaspore while the remaining products of meiosis degenerate. This haploid megaspore will have three mitotic divisions accompanied by nuclear movement to create a defined pattern at each division.
Is megaspore mother cell diploid or haploid?
•MMC or Megaspore Mother Cell is a diploid cell which develops in the Nucellus of the ovule. MMC undergoes meiotic division to produce four haploid megaspores out of which, only one remains functional and the other three degenerate. Hence, only MMC is diploid and rest are haploid structures.
Is egg cell haploid or diploid?
Egg cell is haploid and on fusion with male gamete produces a diploid zygote. Hence, egg is haploid. •Megaspore is formed from the megaspore mother cell. Megaspore mother cell is diploid and undergoes meiosis to produce four haploid megaspores. Hence, megaspore is haploid.
What is the difference between egg and megaspore?
•Egg is the female gamete present in the embryo sac. Egg cell is haploid and on fusion with male gamete produces a diploid zygote. Hence, egg is haploid. •Megaspore is formed from the megaspore mother cell. Megaspore mother cell is diploid and undergoes meiosis to produce four haploid megaspores.
How many megaspores are in a single cell?
The megasporocyte is a single cell that undergoes meiosis, producing a tetrad of four haploid megaspores (megasporogenesis). In most extant seed plants the four megaspores are arranged in a straight line, or linearly (Figure 5.10A).