Why is the endosperm of angiosperms triploid Class 11?
Endosperm is formed during the double fertilization. It is triploid because it is formed when one of the two sperm that is haploid enters inside the embryo sac & fuses with two polar nuclei (each polar nuclei is haploid). So the endosperm formed is triploid.
Why is the endosperm in angiosperm triploid?
Double fertilization is a distinctive feature of angiosperms. Each ovule receives a pollen tube that delivers two sperm cells to the embryo sac. One sperm fertilizes the egg cell, generating the diploid zygote, while the other sperm fertilizes the central cell giving rise to endosperm that is usually triploid.Aug 30, 2002
What is endosperm and why is it triploid?
The endosperm of the flowering plant mediates the supply of maternal resources for embryogenesis. An endosperm formed in sexual reproduction between diploid parents is typically triploid, with a 2 : 1 ratio of maternal genetic material (denoted as 2m : 1p).
Do angiosperms have triploid endosperm?
Endosperm is a triploid tissue in angiosperms, because double fertilization results in the formation of a diploid zygote and a triploid endosperm. The female gametophyte or embryo sac has an egg nucleus and two polar nuclei. One sperm fertilizes the egg nucleus and forms the zygote, 2n.
Where is triploid endosperm found?
In most flowering plants, the central cell contains two haploid nuclei, which fuse prior to or at fertilization. The fusion of this homodiploid nucleus with the sperm nucleus results in a triploid primary endosperm nucleus with two maternal and one paternal genome complements (2m:1p).
Do gymnosperms have triploid endosperm?
Both gymnosperms and angiosperms have a haploid female gametophyte but only angiosperms form a triploid endosperm from multiple fertilizations.
Do angiosperms have diploid endosperm?
We show that diploid endosperms are common among early angiosperm lineages and may represent the ancestral condition among flowering plants.Jan 31, 2002
Why is the endosperm nucleus triploid?
In most flowering plants, the central cell contains two haploid nuclei, which fuse prior to or at fertilization. The fusion of this homodiploid nucleus with the sperm nucleus results in a triploid primary endosperm nucleus with two maternal and one paternal genome complements (2m:1p).
How is the primary endosperm nucleus triploid?
In most flowering plants, the central cell contains two haploid nuclei, which fuse prior to or at fertilization. The fusion of this homodiploid nucleus with the sperm nucleus results in a triploid primary endosperm nucleus with two maternal and one paternal genome complements (2m:1p).
Which type of endosperm is found in angiosperm triploid?
In angiosperms there are three types of endosperm development— namely, nuclear, cellular, and helobial. The mature endosperm in some plants shows rumination that is caused by the seed coat activity or by the endosperm itself. The endosperm haustoria are of widespread occurrence in angiosperms.
Which endosperm is triploid?
An endosperm formed in sexual reproduction between diploid parents is typically triploid, with a 2 : 1 ratio of maternal genetic material (denoted as 2m : 1p). Variation from this ratio affects endosperm size, indicating parent-specific expression of genes involved in endosperm growth and development.