1.综合题- (共1题)

(1)蚕的这种发育过程从幼体到成体有较大的变化,称为 。
(2)蚕的体细胞中有28对染色体,它产生的精子或卵细胞中染色体的数目是 。
(3)课外养蚕小组的同学发现,黄足蚕结黄茧,白足蚕结白茧。他们选用黄足蚕与白 足蚕杂交,后代全是黄足蚕,说明黄足是 性状;如果控制相对性状的基因用A、a表示,则蚕的白足基因组成分别是 。
(4)2008年,我国的桑蚕育种专家将水母的绿色荧光蛋白基因转移到桑蚕的体内,培 育出能吐绿色荧光蚕丝的新品种。这项现代生物技术称为 。
2.单选题- (共9题)
A.人的体细胞中若多一条21号染色体,将表现为先天愚型 |
B.同一品种的小麦在水肥条件不同的环境中,所结籽粒的饱满程度不同 |
C.利用太空技术育种培育的太空椒 |
D.—对有耳垂的夫妇生出了有耳垂的孩子 |
A.化石是研究生物进化最直接的证据 |
B.化石是指古代生物的遗体、遗物或生活痕迹 |
C.通过对不同年代化石的比较,可推断出生物进化的趋势 |
D.和鸟类的化石相比,恐龙化石出现在较早的地层中 |
A.细菌对抗生素的选择作用 | B.抗生素对细菌的选择作用 |
C.产品的质量下降 | D.人类的体质下降 |
3.选择题- (共3题)
A young man went to the local expert(专家) on gems and said he wanted to become a gemologist(珠宝家). The expert turned him down because he feared the youth would not have the patience to learn. The young man asked for a chance. Finally, the expert told the youth, "Be here tomorrow."
The next morning the expert put a jade(玉) stone in the youth's hand and told him to hold it. The expert then went about his work, cutting, weighing and setting gems. The boy sat quietly and waited.
The following morning the expert again put the jade stone in the youth's hand and told him to hold it. On the third, fourth and fifth days, the expert asked the young man to do the same thing. On the sixth day, the youth held the jade stone but he could no longer stand(忍受) the silence. "Master, when am I going to learn something?" he asked. "You will learn." the expert said and went about his business.
Several more days went by and the youth almost lost his patience. But one morning as the master put the stone in the youth's hand, the young man said without looking at his hand, "This is not the same jade stone!" "You have begun to learn." said the master.
Practice makes perfect. The experience we learned from practice teaches us and develops our abilities. Experience is the best teacher. Even the most successful person had no absolute confidence once. It is experience that gives people confidence. The truth is: if you do the work and gain the experience, you'll have more confidence because you'll actually know what you're doing.
A young man went to the local expert(专家) on gems and said he wanted to become a gemologist(珠宝家). The expert turned him down because he feared the youth would not have the patience to learn. The young man asked for a chance. Finally, the expert told the youth, "Be here tomorrow."
The next morning the expert put a jade(玉) stone in the youth's hand and told him to hold it. The expert then went about his work, cutting, weighing and setting gems. The boy sat quietly and waited.
The following morning the expert again put the jade stone in the youth's hand and told him to hold it. On the third, fourth and fifth days, the expert asked the young man to do the same thing. On the sixth day, the youth held the jade stone but he could no longer stand(忍受) the silence. "Master, when am I going to learn something?" he asked. "You will learn." the expert said and went about his business.
Several more days went by and the youth almost lost his patience. But one morning as the master put the stone in the youth's hand, the young man said without looking at his hand, "This is not the same jade stone!" "You have begun to learn." said the master.
Practice makes perfect. The experience we learned from practice teaches us and develops our abilities. Experience is the best teacher. Even the most successful person had no absolute confidence once. It is experience that gives people confidence. The truth is: if you do the work and gain the experience, you'll have more confidence because you'll actually know what you're doing.
A young man went to the local expert(专家) on gems and said he wanted to become a gemologist(珠宝家). The expert turned him down because he feared the youth would not have the patience to learn. The young man asked for a chance. Finally, the expert told the youth, "Be here tomorrow."
The next morning the expert put a jade(玉) stone in the youth's hand and told him to hold it. The expert then went about his work, cutting, weighing and setting gems. The boy sat quietly and waited.
The following morning the expert again put the jade stone in the youth's hand and told him to hold it. On the third, fourth and fifth days, the expert asked the young man to do the same thing. On the sixth day, the youth held the jade stone but he could no longer stand(忍受) the silence. "Master, when am I going to learn something?" he asked. "You will learn." the expert said and went about his business.
Several more days went by and the youth almost lost his patience. But one morning as the master put the stone in the youth's hand, the young man said without looking at his hand, "This is not the same jade stone!" "You have begun to learn." said the master.
Practice makes perfect. The experience we learned from practice teaches us and develops our abilities. Experience is the best teacher. Even the most successful person had no absolute confidence once. It is experience that gives people confidence. The truth is: if you do the work and gain the experience, you'll have more confidence because you'll actually know what you're doing.
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【1】题量占比
综合题:(1道)
单选题:(9道)
选择题:(3道)
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【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:0
5星难题:0
6星难题:5
7星难题:0
8星难题:2
9星难题:3