WebThe nucleus with its chromatin and nucleolus is still intact. The ER is predominantly of a tubular anastomosing form, while in adjacent cells it is predominantly of a flattened cisternal variety. Note electron opaque region of the wall surrounding the differentiating element (arrow). X 14,500. Web20 jul. 1998 · Sieve tube elements are almost always adjacent to nucleus-containing companion cells, which have been produced as sister cells with the sieve element from …

Nucleus is absent in - Tardigrade

Web24 feb. 2024 · Phloem is the tissue system responsible for the movement of food materials in the plant - especially sugar made through photosynthesis. The sieve tube member is a mature phloem cell involved with long distance movement of food material. They are living cells, but lack a nucleus. The protoplasts are connected through sieve areas between … WebSieve tube loses its nucleus at maturity becauseits mainfunction is to transport sugars and other important molecules necessary for plants. It would thus require a lot of space to … how to create google drive for business

The nucleus is absent in the maturea. Sieve tube cellsb.

Web8 dec. 2024 · In matured sieve tube, nucleus is absent. It contains a lining layer of cytoplasm. This is an important feature of sieve elements. A special protein called slime body is seen in it. The conduction of food material … WebThere are two types of sieve elements: sieve cells and sieve tube members (Figure 4.6A). Sieve cells have only sieve areas on both end and side walls.Sieve tube members have both sieve areas and sieve plates (Figure 4.5B). Sieve plates consist of one or more sieve areas at the end-wall junction of two sieve tube members; the pores of a sieve plate, … Web1 Answer. The sieve tubes of the phloem in angiosperms consist of sieve tube elements or members. These are cells which lose their nucleus, ribosomes, and vacuoles at … microsoft search索引缓存可以删除吗