题干

在细胞免疫中,效应T细胞杀伤靶细胞主要有两种途径:细胞裂解性杀伤(图1)和诱导细胞凋亡(图2).前者指效应T细胞分泌诸如穿孔素一类的介质损伤靶细胞膜,后者指效应T细胞通过表面FasL,与靶细胞表面的Fas结合,诱导靶细胞凋亡.请分析并回答:

(1)人体内的效应T细胞来自____ 的增殖、分化.

(2)图1中的穿孔素又称“成孔蛋白”,由效应T细胞产生并以____ 的方式释放到细胞外.穿孔素能在靶细胞膜上形成多聚穿孔素管状通道,使K+及蛋白质等大分子物质____ (流入/流出)靶细胞,最终导致靶细胞死亡.

(3)图2中的FasL又称死亡因子,Fas又称死亡因子受体,它们都是由细胞合成并定位于细胞表面的蛋白质.一般来说,控制FasL的基因____ (填“是”或“不是”)只在效应T细胞和某些细胞内表达.

①Fas和FasL的结合体现了细胞膜的____ 功能,控制合成Fas和FasL的基因____ (填“是”或“不是”)共存于一个细胞中.

②研究发现,某些肿瘤细胞能够调节Fas和FasL基因的表达水平,从而使自己逃脱免疫系统的清除.此时,肿瘤细胞内Fas基因的表达变化情况是____ (填“升高”“不变”或“降低”).免疫排斥是器官移植的一个主要障碍,根据上述实例及Fas和FasL的相互关系,可考虑____ 基因的表达,从而为解决免疫排斥提供一种新的思路.

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答案(点此获取答案解析)

T细胞或记忆T细胞,胞吐,流出,是,信息交流,是,降低,阻碍FasL

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    How many girls in this world fall behind? The answer is hard—too many to count. This is why the phrase “Go Get It Girl” popped up in my head one day. This would be my project. Thus begins the journey of my Cold Award project, the largest and most important step of Girl Scouts (女童子军).

    “Go Get It Girl” is a girl's self-empowerment (自我授权) project centered on a website called gogetitgirl.org. It focuses on areas including education, health, and financial literacy. The education section includes information on applying to college and, maintaining good grades. The health section contains information on basic health and self-respect. Lastly, the financial literacy section has all the information a girl needs to manage her money properly.

    As part of my project, I was able to work one-on-one with girls in elementary, middle, and high school. I gave a speech at a local high school's College Night. I spoke to Hispanic girls and their parents about applying to college. In addition, I worked with an organization called Cool Girls, Inc. Cool Girls is an organization focused on the advancement of girls in all aspects of their development. I worked at the afterschool program, Cool Girls Club. The girls I worked with were primarily minorities, and Cool Girls truly helps them to rise above any current difficulties in their lives.

    To provide inspiration for the girls who visit gogetitgirl.org, I interviewed successful women in my community, including a doctor and business owner.

The project has been a lot of work, arid it's not over yet. It will never be over, hopefully, because I will always look for ways to help girls.