[简答题]The Ras protein functions as a molecular switch that is set to its onstate by a guanine-nucleotide exchange factor (GEF) that causes it to bind GTP. A GTPase-activating protein (GAP) resets the switch to the off state by inducing Ras to hydrolyze its bound GTP to GDP much more rapidly than in the absence of the GAP. Thus Ras works like a light switch that one person turns on and another turns off. In a cell line that lacks the Ras-specific GAP, what abnormalities would you expect to find in the way Ras activity responds to extracellular signals

[单项选择]MDS-RAS
A. 骨髓粒、红两系病态造血，骨髓原始细胞＞5%，环形铁粒幼红细胞＞15%
B. 骨髓粒、红两系病态造血，骨髓原始细胞＜5%，环形铁粒幼红细胞＜15%
C. 骨髓粒、红两系病态造血，骨髓原始细胞5%～20%，单核细胞＞1×10⁹/L
D. 骨髓粒、红两系病态造血，骨髓原始细胞21%～30%，单核细胞＜1×10⁹/L
E. 骨髓粒、红两系病态造血，骨髓原始细胞5%～20%，单核细胞＜1×10⁹/L

[名词解释]Protein C system

[单项选择]Ras基因家族属于
A. 细胞原癌基因
B. 抑癌基因
C. 病毒癌基因
D. 操纵子调节基因

[单项选择]Ras蛋白有（）
A. 3个非同源亚基
B. 3个同源亚基
C. 2个非同源亚基
D. 2个同源亚基
E. 1个亚基

[填空题]Switch0、Switch1、Switch2和Switch3均为二层交换机。总部拥有的IP地址块为202.114.12.0/24。Switch0的端口e0/24与路由器R2的端口e0/0相连，请根据图17-25完成路由器R2及Switch0的配置。
R2(config)#interface fastethernet 0/0.1
R2(config-subif)#encapsulation dotlq (3)
R2(config-subif)#ip address 202.114.12.1 255.255.255.192
R2(config-subif)#no shutdown
R2(config-subif)#exit
R2(config)#interface fastethernet 0/0.2
R2(config-subif)#encapsulation dotlq (4)
R2(config-subif)#ip address 202.114.12.65 255.255.255.192
R2(config-subif)#no shutdown
R2(config-subif)#exit
R2(config)#interface fastethernet 0/0.3
R2(config-subif)#encapsulation dotlq (5)
R2(config-subif)#ip address 202.114.12.129 255.255.255.192
R2(config-subif)#no shutdown
R2(config-subif)#exit
R2(config)#interface fastether0/0
R2(config-if)#no shutdown
Switch0(config)#interface f0/24
Switch0(config-if)#switchport mode (6)
Switch0(config-if)#switchport trunk e

[简答题]

阅读以下的配置信息，解释(5)处的命令。
Switch#
Switch#cofing
Switch(cofing)#interface fo/1 //进入接口1配置模式
Switch(cofing-if)#switchport mode truck (5)
Switch(cofing-if)#switchport truck allowed vlan all //设置允许从该接口交换数据的vlan
Switch(cofing-if)#exit
Switch(cofing)#exit
Switch#

[简答题]

Th细胞

[简答题]阻遏蛋白(repressor protein)

[简答题]蛋白激酶(protein kinase)

[简答题]bZIP蛋白(bZIP protein)

[简答题]Th1

[简答题]同源蛋白质(homologous protein)

[填空题]在switch语句中，通过______语句退出switch语句，使程序从整个switch语句后面的第一条语句处开始执行。

[单项选择] K-ras激活和p53突变属于
A. 与大气污染有关的疾病资料
B. 儿童生长发育指标
C. 生理或生化指标
D. 免疫指标
E. 人体的遗传毒性指标

[简答题]抗终止蛋白(antitermination protein)