Difference Between Integument and Testa

Thekey differencebetween integument and testa is that theintegument is the outermost covering of anovule,while the testa is the outermost covering of a seed.

Sexual reproduction takes place between two types of gametes:male and female gametes. The ovule is the female gamete while the花粉带有男配子。男性和女配子团结并产生二倍体合子。卵巢是带有胚珠的结构。外观是胚珠的保护覆盖物。受精后，胚珠形成种子。鉴于，外神经出现在被称为睾丸的种子外套中。

内容

1.Overview and Key Difference
2.What is Integument
3.What is Testa
4.Similarities Between Integument and Testa
5.Side by Side Comparison – Integument vs Testa in Tabular Form
6.概括

What is Integument?

The integument is the outer covering of the ovule. It is a protective layer. Gymnosperms have a single integument while there are two integuments surrounding the ovule in angiosperms. Structurally, the integument is thin and smooth. It consists of living cells. Hence, it does not containsclereids, unlike testa.

Furthermore, integuments do not enclose the nucellus completely. Nucellus remains open at the micropyle to facilitate entering of pollens inside the ovule for syngamy. Integuments originate from the chalazal end of the ovule. It is actually a pre-fertilization structure. Thus, integument develops into testa or seed coat after fertilization and maturation.

What is Testa?

Testa is the outermost protective covering of the seed. Thus, it is one of the two seed coats which is brownish in colour. The outer integument gives rise to testa. Hence, it is a post-fertilization structure. Structurally, there are two layers of the testa as endotesta and exotesta. Its main function is to protect the developing embryo from mechanical damages and dehydration.

此外，睾丸在分散种子过程中保护种子。因此，它是由诸如Sclereids之类的死细胞组成的厚而坚硬的覆盖物。此外，它是不渗透的。有时，Testa的这种特性导致种子休眠。

What are the Similarities Between Integument and Testa?

• Integument and testa can be seen in flowering plants.
• Both structures are related to the sexual reproduction of plants.
• Moreover, integuments develop into the seed coat when the ovule matures after fertilization.

What is the Difference Between Integument and Testa?

Integument and testa are two outermost coverings. Integument surrounds the ovule while testa surrounds the seed. So, this is the key difference between integument and testa. Moreover, the integument is a smooth and thin layer composed of living cells. In contrast, testa is a thick and hard layer composed mainly of dead cells. Furthermore, integument protects the ovule while testa protects the seed. Therefore, this is also a significant difference between integument and testa. In addition to these, the integument is a pre-fertilization structure, while testa is a post-fertilization structure.

概括– Integument vs Testa

The integument is the outermost covering of the ovule. Therefore, it protects the ovule. It is a thin layer composed of living cells. Testa, on the other hand, is the protective outer covering of a seed. It is a thick and hard covering composed of dead cells, mainly sclereids. After fertilization, outer integument develops into testa. Testa protects the seed. It also plays a big role in seed dormancy. So, this is the summary of the difference between integument and testa.

Reference:

1.“Seed.” Wikipedia, Wikimedia Foundation, 8 Oct. 2019,Available here.
2. “Ovule.” Wikipedia, Wikimedia Foundation, 1 Aug. 2019,Available here.

Image Courtesy:

1. “Ovule-Gymno-Angio-en” By derivative work: Qef (talk)Ovule-Gymno-Angio-fr.svg: Original uploader was Tameeria at en.wikipedia. Translation and vectorisation by Cehagenmerak. – Ovule-Gymno-Angio-fr.svg (Public Domain) viaCommons Wikimedia
2. “Coconut layers” By Kerina yin – Own work(CC BY-SA 3.0)viaCommons Wikimedia