Structure of transport tissues · 运输组织的结构
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| xylem/ˈzaɪləm/ | 木质部 | mù zhì bù |
| phloem/ˈfləʊɪm/ | 韧皮部 | rèn pí bù |
| vessel/ˈvesl/ | 导管 | dǎo guǎn |
| lignin/ˈlɪɡnɪn/ | 木质素 | mù zhì sù |
| sieve tube/sɪv tjuːb/ | 筛管 | shāi guǎn |
| companion cell/kəmˈpænɪən sel/ | 伴胞 | bàn bāo |
| sieve plate/sɪv pleɪt/ | 筛板 | shāi bǎn |
Transport tissues in plants
- A plant must move water up and food around — two different jobs.
- So it has two transport tissues: xylem 木质部 and phloem 韧皮部.
- Their structure is beautifully matched to what they carry.
植物中的运输组织
- 一株植物必须把水 向上 运,把食物 四处 运——两个不同的工作。
- 所以它有两种运输组织:木质部(xylem) 和 韧皮部(phloem)。
- 它们的结构与它们运输的东西完美匹配。
Xylem vs phloem
| Xylem | Phloem | |
|---|---|---|
| carries | water + mineral ions | dissolved sugars (assimilates) |
| direction | up from roots | to wherever needed (source → sink) |
| cells | dead, empty | living |
- In a stem they sit in bundles near the outside (xylem on the inside); in a root the xylem is a central star; in a leaf both are in the veins.
Xylem (water, up) and phloem (sugars) side by side
木质部与韧皮部
| 木质部 | 韧皮部 | |
|---|---|---|
| 运输 | 水 + 矿物离子 | 溶解的糖(同化物) |
| 方向 | 从根 向上 | 到任何需要的地方(源 → 库) |
| 细胞 | 死的、空的 | 活的 |
- 在 茎 中它们成束位于外侧附近(木质部在内侧);在 根 中木质部是一个中央的星形;在 叶 中两者都在叶脉中。
木质部(水,向上)和韧皮部(糖)并排
Which statement is correct? · 哪个陈述是正确的?
Xylem moves water and mineral ions upward; phloem moves dissolved assimilates (mainly sucrose). · 木质部把水和矿物离子向上运;韧皮部运输溶解的同化物(主要是蔗糖)。
Xylem vessels 导管
- Xylem tubes are vessels: dead, empty cells joined end to end with the end walls gone — one long open pipe.
- The walls are thickened and waterproofed with lignin 木质素.
- So: the hollow tube lets water flow fast, and the lignin gives strength and support.
A stem vascular bundle: xylem and phloem grouped together
木质部导管
- 木质部管是 导管(vessels):死的、空的细胞首尾相接,端壁消失——一根长长的开放管道。
- 壁被 木质素(lignin) 加厚并防水。
- 所以:中空的管让水 快速流动,木质素给出 强度和支撑。
一个茎维管束:木质部和韧皮部组合在一起
Xylem vessels are strengthened and waterproofed by ______ in their walls. · 木质部导管由它们壁中的 ______ 加强并防水。
Lignin makes a strong, waterproof, hollow pipe — and the cells die, leaving an open tube. · 木质素制造一根结实、防水、中空的管道——细胞死亡,留下一根开放的管。
A mature xylem vessel is a living cell, full of cytoplasm and a nucleus. · 一个成熟的木质部导管是一个活细胞,充满细胞质和一个细胞核。
Xylem vessels are dead and empty — that is what makes them a fast, open pipe for water. · 木质部导管是死的且空的——这就是使它们成为一根快速、开放的运水管道的原因。
Phloem sieve tubes 筛管 and companion cells 伴胞
- Phloem tubes are sieve tubes: living cells joined end to end. Their end walls become sieve plates 筛板 with holes for sap. To leave room, the cell loses most contents and has no nucleus.
- Each sieve tube has a companion cell beside it — it keeps its nucleus and many mitochondria, and does the living work, loading sugars in.
韧皮部筛管和伴胞
- 韧皮部管是 筛管(sieve tubes):活细胞首尾相接。它们的端壁变成带孔供汁液通过的 筛板(sieve plates)。为了腾出空间,细胞失去大部分内容物并 没有细胞核。
- 每根筛管旁边有一个 伴胞(companion cell)——它保留它的 细胞核 和许多 线粒体,做活的工作,把糖装载进去。
Xylem and phloem side by side · 木质部和韧皮部并排
Tap each part. Xylem is a dead, hollow pipe for water; phloem is a living tube for sugars, helped by its companion cell. · 点击每个部分。木质部是一根死的、中空的运水管道;韧皮部是一根运糖的活管,由它的伴胞帮助。
The companion cell beside a sieve tube: · 一根筛管旁边的伴胞:
The sieve tube loses most contents, so the companion cell (with nucleus and mitochondria) does the living work. · 筛管失去大部分内容物,所以伴胞(带细胞核和线粒体)做活的工作。
Match each structure to its description. · 把每个结构与它的描述配对。
Xylem = dead lignified pipe; sieve tube = living with sieve plates; companion cell = nucleus + loads sugar. · 木质部 = 死的木质化管道;筛管 = 活的带筛板;伴胞 = 细胞核 + 装载糖。
Sieve plates are: · 筛板是:
Sieve plates are perforated end walls between sieve-tube cells, allowing sap to pass along the phloem. · 筛板是筛管细胞之间有孔的端壁,允许汁液沿韧皮部通过。
You've got it
- xylem: water + minerals up; dead, empty vessels with lignin (fast flow + support)
- phloem: sugars to where needed; living sieve tubes with sieve plates and no nucleus
- each sieve tube has a companion cell (nucleus + mitochondria) that loads sugar
- stem: bundles near outside; root: central xylem star; leaf: in the veins
你掌握了
- 木质部:水 + 矿物质 向上;死的、空的 导管,带 木质素(快速流动 + 支撑)
- 韧皮部:糖到需要的地方;活的 筛管,带 筛板,没有细胞核
- 每根筛管有一个 伴胞(细胞核 + 线粒体)装载糖
- 茎:成束在外侧附近;根:中央木质部星形;叶:在叶脉中