题干

水稻是我国南方地区重要的粮食作物,但在水稻的生育期中,稻瘟病危害水稻的生长发育,导致减产.稻瘟病引起水稻病症主要有褐色病斑型和白点病斑型,采用适宜播种方式可控制感病程度.下表是株高和株型相近的水稻A、B两品种在不同播种方式下的实验结果:

播种方式

试验编号

植株密度(×106株/公顷)

褐色病斑型发病程度

白点病斑型发病程度

单位面积

产量


品种A

品种B

1

单播

6

0

+++

+

2

单播

3

0

++

++

3

混播

3

3

+

+

+++

4

单播

0

6

+++

+

5

单播

0

3

++

++

注:“+”的数目越多表示发病程度越高或产量越高,“一”表示未染病.

据题干信息及表中信息回答下列问题:

(1)抗白点病斑型的水稻是品种____ ,判断依据是____ .

(2)设计1、2两组实验,可探究____ .

(3)1、3、4三组相比,第3组产量最高,可能原因是____ .

(4)稻瘟病病原体与水稻之间属于____ 关系.若实验田的水稻被某种鸟大量捕食而明显减少时,该鸟的部分个体会另觅取食地,这属于生态系统中的____ 信息,体现了生态系统的____ 功能.若用标志重捕法调查该鸟的种群密度时标志物脱落,计算所得数值与实际数值相比,可能

____ (选填“偏小”或“相等”或“偏大”).

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答案(点此获取答案解析)

B,4\u30015\u6c34\u7a3b\u90fd\u672a\u611f\u67d3\u767d\u70b9\u75c5\u6591\u578b,\u690d\u682a\u5bc6\u5ea6\u5bf9\u54c1\u79cdA\u6c34\u7a3b\u611f\u75c5\u7a0b\u5ea6\u53ca\u4ea7\u91cf\u7684\u5f71\u54cd,\u6df7\u64ad\u540e\u6c34\u7a3b\u53d1\u75c5\u7a0b\u5ea6

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    I have a friend named Monty Roberts who owns a horse ranch(牧马场). The last time I was there he told me his story. When he was young, his family was too poor to have a house to live in.As a result , when he was in high school, all the students were asked to write a paper about what they wanted to be and do when they grew up. That night he wrote a seven-page paper describing his goal of owning a horse ranch. He also drew a picture to show a 4,000-square-foot house that would sit on a beautiful farm. The next day he handed it in to his teacher. Two days later he received his paper back. On the front page was a large red F. Roberts asked, “Why did I receive an F?” He teacher said, “This is an unrealistic dream for a young boy like you. Owning a horse ranch requires a lot of money.” Then the teacher added, “If you will rewrite this paper with a more realistic goal, I will reconsider your grade.”

    The boy went home and thought about it for a long and hard time. He asked his father what he should do. His father said, “ Look, son, you have to make up your own mind on this. However, I think it is a very important decision for you.”Finally, after sitting with it for a week, the boy turned in the same paper, making no changes at all. He told his teacher “you could keep the F and I still keep my dream”.

    He tells me this story because I am sitting in his 4,000-square-foot house in the middle of the 200-acre horse ranch. “I still have that school paper now.” He added, “The best part of the story is that two years ago that  teacher brought 30 kids to camp out on my ranch for a week.” When the teacher was leaving, he said, Look, Monty, I can tell you this now. When I was your teacher, I was something of a dream stealer.During those years I stole a lot of kids' dreams. Luckily, you had enough gumption not to give up on yours. .”