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标题: 揽瓜阁做题小分队第17天 Toxoplasma gondii [打印本页]

作者: 小白斩鸡 时间: 2021-4-16 14:48
标题: 揽瓜阁做题小分队第17天 Toxoplasma gondii

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The single-celled parasite known as Toxoplasma gondii infects more than half of the world's human population without creating any noticeable symptoms. Once inside the human body, Toxoplasma rapidly spreads to the heart and other organs. It can even penetrate the tight barrier that normally protects the brain from most pathogens. Yet, the blood of infected persons carries very few free-floating Toxoplasma cells. Scientists have long been puzzled by this ability of Toxoplasma to parasitize the human body without triggering an immune response and without an appreciable presence in the bloodstream. Recent research, however, has shed light on the ways in which Toxoplasma achieves its remarkable infiltration of the human body.

Though there are few individual Toxoplasma cells coursing freely in the blood of an infected person, scientists have discovered that the parasite is quite common in certain cells, known as dendritic cells, involved in the human immune system. Dendritic cells are found in the digestive tract and frequently come into contact with the various pathogens that enter the human body through food and water. When the dendritic cells encounter pathogens, they travel to lymph nodes and relay this information to other immune cells that then take action against the reported pathogen. Scientists have found, however, that Toxoplasma is capable of hijacking dendritic cells, forcing them from their usual activity and using them as a form of transportation to infect the human body quickly. Without this transport mechanism, Toxoplasma could not reach the better-protected areas of the body.

Toxoplasma invades the human body through consumption of the undercooked meat of infected animals, primarily pigs and chickens. Other animals, such as cats, can become infected as well. In fact, cats are a necessary component in the reproductive cycle of Toxoplasma, since the animal's intestines are the parasite's sole breeding ground. Toxoplasma creates egg-like cysts, known as oocysts, in the cats' intestines. These oocysts are shed in the cats' droppings and contaminate ground water and soil, eventually finding their way into the food chain. Because Toxoplasma must somehow find its way into a new host cat in order to reproduce, it cannot kill its current host. Instead, it waits for the host, usually a small rodent, to be eaten by a cat, thus providing Toxoplasma the opportunity to reproduce.

1. According to the passage, all of the following are true of Toxoplasma gondii EXCEPT
(A) it can contaminate ground water
(B) it enters the human body through the food chain
(C) it can alter the usual behavior of human cells
(D) the human body is incapable of detecting it
(E) it must find a host cat in order to reproduce

2. It can be inferred from the passage that which of the following statements is true of dendritic cells in the human body?
(A) They are produced by the lymphatic system.
(B) They are more numerous in the digestive tract than in any other part of the human body.
(C) Most dendritic cells of persons infected with Toxoplasma carry the parasite.
(D) They are the only cells capable of being infected by Toxoplasma.
(E) They are able to penetrate the membranes surrounding the brain.

3. Which of the following is the most likely outcome for Toxoplasma cells that invade the human body?
(A) They will be destroyed by the immune system.
(B) They will collect in the lymphatic system.
(C) They will not reproduce.
(D) They will be detected after several weeks.
(E) They will be destroyed by other pathogens in the bloodstream.

4. The second paragraph performs which of the following functions in the passage?
(A) It describes a paradox that scientists were unable to resolve for some time.
(B) It explains the effectiveness of a lethal biological pathogen.
(C) It describes the mechanism by which a biological event occurs in humans.
(D) It demonstrates how the infectious agent reproduces itself.
(E) It introduces information that is essential to understanding the role of Toxoplasma in human development.

5. The author mentions “pigs and chickens” in the final paragraph in order to
(A) provide specific examples of animals that can carry Toxoplasma
(B) provide specific examples of animals that are often eaten by cats
(C) provide specific examples of other animals whose dendritic cells are exploited by Toxoplasma
(D) provide specific examples of animals in which Toxoplasma can breed
(E) provide specific examples of animals that are immune to Toxoplasma

参考答案，做完才看：）

作者: CCCGO 时间: 2021-4-16 15:38
CECAD

作者: N0ire 时间: 2021-4-16 15:56
10min
主旨：弓形虫如何繁殖并感染人类
P1: （提出问题）弓形虫感染很普遍，但它如何逃过免疫系统是个谜
P2: （新的发现）弓形虫挟持树状细胞逃避免疫系统，同时借助它们侵入人体各个区域
P3: （补充源头）弓形虫进入人体的渠道以及其借以繁殖的宿主

CEBCA

作者: 123Better 时间: 2021-4-16 16:28
CEBCA

作者: 速水愛媛 时间: 2021-4-16 17:07
DEACA

作者: puy123 时间: 2021-4-16 19:00
用时12min左右
1、介绍T寄生虫的行为；
2、介绍T寄生虫的能力；
3、介绍T的传播
MA: EECCA
OA: DECCA

pathogen 病原体
intestine 肠
infiltrate 渗入
hijacking 劫持
forcing them from usual activities 迫使他们停止正常活动

第一题，哪里有写人类身体能发现T吗？（是不是因为也没有写不能发现？就没提到？但不是说可以不触动免疫反应吗）
第二题犹豫的D选项，有写到T只是在d细胞多，也有部分在血液里
第三题，完全迷惑，为毛选C，我选这个只是因为其他更加不对

作者: yyking625 时间: 2021-4-16 21:49
ECBCA

作者: 半日大哥 时间: 2021-4-16 22:22
EEBCA
用时9分钟
1. 寄生虫T能够感染人类，却不引起免疫反应或者症状。科学家一直不明白为什么人们很容易感染T却又没反应。
2. T 能够存在于D细胞中，随着D细胞通过淋巴循环到达人体其他地方。
3. T 通过未熟的肉类进入人体。动物的肠道几乎是T唯一的繁殖处。 T 会产生类似虫卵的东西随着动物粪便进入地面、水系等等，从而进入食物链。

作者: 阿綠 时间: 2021-4-17 08:52
同意！

作者: 暴躁少女本人 时间: 2021-4-17 11:22
CEDAA

作者: LouisTan 时间: 2021-4-17 15:56
ECBCA

作者: HHHHRane 时间: 2021-4-17 20:06
DEBCA

作者: 星v座v书v上 时间: 2021-4-17 21:07
CEBCA

作者: LindsayPark 时间: 2021-4-18 02:59
DBCCA
P1:介绍TG，提出一个puzzle，嘴周说这个puzzle被解决
P2:进一步说TG是怎么运作的
P3：怎么容易感伤tg和tg如何再生

作者: Charlotte_Dou 时间: 2021-4-18 10:21
CBCAA

作者: auttoautto 时间: 2021-4-18 13:34
1. 弓形虫感染人体而造成症状被免疫细胞发现
2. 弓形虫利用树形细胞作为媒体进行传输
3. 弓形虫如何进行繁殖
DCCBA

作者: RxxMewo 时间: 2021-4-18 15:04
DCCCA 14min

作者: 2022Tiramisu 时间: 2021-4-18 20:14
CEBCA

作者: yutingw 时间: 2021-4-19 16:32
DBCCA

作者: irisville 时间: 2021-4-19 18:35
dccca 8 min

作者: Jack.Lu 时间: 2021-4-19 18:52
CEBCA
P1:Toxoplasma感染很普遍，但是却没有免疫反应
P2:Toxoplasma的感染原理
P3:Toxoplasma因为煮熟进入人体

作者: 大大大kk 时间: 2021-4-19 22:20
DEBCA

作者: Sibaiyuan 时间: 2021-4-19 23:00
BECCA

第一题是免疫系统不反应不代表不识别？

作者: FuFu_ 时间: 2021-4-20 09:51
CCCCA

作者: FCAENG 时间: 2021-4-20 10:33
CECEA

作者: sssszzzzxccsc 时间: 2021-4-20 22:00
DEBCA

作者: yyking625 时间: 2021-4-20 23:12
DECCA

作者: rs曦曦 时间: 2021-4-20 23:34
one single-celled parasite, Toxo, is common in the human body, but it doesn't trigger the immune response. scientists used to be puzzled by the mechanism.
penetration mechanism of Toxo in human bodies: taking DEND cells as transportation traveling to the membrane of the brain.
how does the TOXO break into human bodies? through food chain, rely on cats to reproduce

作者: ccccherry 时间: 2021-4-21 00:42
CCBAA

作者: 断了的弦 时间: 2021-4-21 08:32
dccca

作者: miemie_yang 时间: 2021-4-24 11:55
答案：A E B A A
描述了Toxoplasma为什么可以感染人体但却没有任何正装，身体免疫系统也没有任何排斥反应，解释了作用机制，以及通过未煮熟的猪肉和肌肉来侵入人体，并介绍了猫这个宿主如何被感染的过程

作者: 飞跃重洋2017 时间: 2021-4-28 01:09
ACCCA

作者: SchodingerCat 时间: 2021-5-12 02:22
DBCCA

作者: 张晴雨 时间: 2021-5-12 10:16
我的答案：DEBCD
正确答案：DECCA
用时：15分钟

作者: 690387114 时间: 2021-6-21 09:16
DECCA

作者: 大月亮cyn 时间: 2021-10-28 16:34
Day17 DCCCA
2. E 好迷惑，文章里说的是T穿透，实际上是D transport了T 那说明D也可以穿透！做的时候觉得C其实也不太对但没想明白E

作者: Flynnisme 时间: 2021-11-14 16:55
阅读时一定要注意那些复杂的单词，比如TOXOPLQSMA GONDII把这个单词放在心里过滤几遍，在下文碰见时就不会不知道这是什么了

第一段：先介绍了一下t病多牛逼，然后因为牛逼科学家不知道发病机理，但最近实验研究就知道了。因此我觉得第一段主要是想介绍一下实验的背景已经引出实验

第二段：t在血液中不自由的原因是因为寄生在其他细胞里，d细胞。正常d细胞作用，然后又介绍了d和t的作用机理。

第三段：t细胞如何进入人体。猫对t细胞的重要性，这里有个绝对词要敏感：sole。又介绍了t是怎么进入猫体的

第一题：细节题，注意except
a在第三段可以找到
b在第三段
c在第二段和d细胞的关系
d在第二段最后，without取非题，看来取非题经常考
e第三段注意sole

第二题：推断题，但有个d细胞因此定位到第二段a
a没说
b没说
c没说
d没说看到only直接排除因为第二段没有绝对词
e最后一句的取非推理出来的

第三题细节题
a没说
b没说
c注意sole因此是对的
d没说
e没说

第四题结构体注意跟全文的关系一看就选c

第五题细节定位题，回到原文看前后句，发现a就适合直接选走人

作者: B及站士 时间: 2023-10-14 17:21
P1 科學家卻疑惑T感染力強甚至能穿越阻礙感染到大腦,但沒什麼感染徵狀,血液裡的T細胞也很少
P2 新研究表示T會綁架人體的C細胞做感染途徑, 沒有這個方法, T其實感染不了人類
P3. 講述T的主要感染途徑跟宿主, 貓是T最唯一的繁衍宿主
-
P1
1. Context: parasite Toxoplasma – infects many people – without any noticeable symptoms
2. Elaborate: rapidly spreads – even penetrate the barrier that protects the brain
but few free-floating T cells in blood
3. Question: how T parasitize human without an immune response and without presence in bloodstream

P2
1. Answer(New research): T is quite common in D cells( in immune system )
2. Elaborate(T’s transport mechanism):
D cells encounter pathogens – inform other immune cells to take action
T can hijack dendritic cells -> reach the better-protected areas of the body

P3
1. T’s sources: through consumption of the undercooked meat – cat can become infected
2. Argument: Cats are a necessary component in the reproductive cycle of Toxoplasma – T eggs + cats’ intestines = cats' droppings (contaminate ground water and soil )
3. Supplement: T need to find a new host cat – waits for the host to be eaten by a cat – providing T the chance to reproduce

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