问题 填空题

如图为细胞模式图,请据图回答下列问题.

(1)细胞最外层坚韧的薄壁是[①]______,其作用是______细胞.

(2)动物细胞和植物细胞具有的基本结构包括[②]______、[④]______、[⑥]______三部分.

(3)水果中的液汁通常存在与细胞的[⑤]______三部分.

(4)遗产物质主要存在于______(填序号)中.

(5)控制物质进出细胞的结构[______]______.

答案

①细胞壁,细胞壁:对细胞具有支持和保护作用.②细胞膜,③叶绿体,④细胞核,⑤液泡,⑥细胞质.其中②细胞膜控制物质的进出,能够让有用的物质进入细胞,把其他物质挡在细胞外面,同时,还能把细胞内产生的废物排到细胞外.④细胞核:内含遗传物质,是遗传的控制中心.

动植物细胞有相同点和不同点,相同点是都有细胞膜、细胞核、细胞质、线粒体,不同点是动物细胞无细胞壁、液泡、叶绿体.

故答案为:

(1)细胞壁 保护和支持

(2)细胞膜 细胞核 细胞质

(3)液泡

(4)④

(5)②细胞膜

多项选择题
单项选择题

Scientists around the world are racing to learn how to rapidly diagnose, treat and stop the spread of a new, deadly disease. SARS — Severe Acute Respiratory Syndrome — was (1) for the first time in February 2003 in Hanoi, (2) since then has infected more than 1,600 people in 15 countries, killing 63. At this (3) , there are more questions than answers surrounding the disease.

Symptoms start (4) a fever over 100.4 degrees F, chills, headache or body (5) . Within a week, the patient has a dry cough, which might (6) to shortness of breath. In 10% to 200% of cases, patients require (7) ventilation to breathe. About 3.5% die from the disease. Symptoms (8) begin in two to seven days, but some reports suggest it (9) take as long as 10 days. Scientists are close to (10) a lab test to diagnose SARS. In the meantime, it is diagnosed by its symptoms. There is no evidence (11) antibiotics or anti-viral medicines help, (12) doctors can offer only supportive care. Patients with SARS are kept in isolation to reduce the risk of (13) . Scientists aren’t sure yet, but some researchers think it’s a (14) discovered coronavirus, the family of viruses that cause some common colds.

Most cases appear to have been passed (15) droplets expelled when infected patients cough or sneeze. Family members of infected people and medical workers who care for them have been most likely to (16) the illness. But recent developments in Hong Kong suggest that the (17) might spread through air, or that the virus might (18) for two to three hours on doorknobs or other (19) Health experts say it is (20) , though, that sharing an elevator briefly with an infected person would be enough to pass the virus.

4()

A.from

B.over

C.upon

D.with