题干

为了加快无子西瓜快速繁殖,科学家常采用植物组织培养的方式进行.下列与此有关的叙述正确的是(  )

A:高度分化的西瓜细胞持续分化的结果

B:高度分化的西瓜细胞具有全能性

C:组织细胞分裂的方式属于无丝分裂

D:上述繁殖个体的方式属于有性生殖

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答案(点此获取答案解析)

B

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阅读短文,回答下列问题。

   My father had always been an alert observer of human character. Within seconds of meeting someone, he could sum up their strengths and weaknesses. It was always a challenge to see if any of my boyfriends could pass Dad's test. None did. Dad was always right—they didn't pass my test either. After Dad died, I wondered how I'd figure it out on my own.

   That's when Jack arrived on the scene. He was different from any other guy I'd dated. He could sit for hours on the piano bench with my mother, discussing some composers. My brother Rick loudly announced that Jack wasn't a turkey like the other guys I'd brought home. Jack passed my family's test. But what about Dad's?

Then came my mother's birthday. The day he was supposed to drive, I got a call. “Don't worry,” he said, “but I've been in an accident. I'm fine, but I need you to pick me up.”

    When I got there, we rushed to a flower shop for something for Mom. “How about gardenias(栀子花)?” Jack said, pointing at a beautiful white corsage (胸花). The florist put the corsage in a box.

The entire ride, Jack was unusually quiet. “Are you all right?” I asked. “I've been doing a lot of thinking,” he said. “I might be moving.” Moving? Then he added, “Moving in with you.” I nearly put the car on the sidewalk. “What?” I asked. “I think we should get married,” he said. He told me he'd planned his proposal in a fancy restaurant, but after the accident, he decided to do it right away. “Yes,” I whispered. We both sat dumbfounded, tears running down our cheeks. I'd never known such a tender moment. If only Dad were here to give his final approval.

  “Oh, let's just go inside.” Jack laughed. My mother opened the door. “Happy Birthday!” we shouted. Jack handed the box to her. She opened it up. Suddenly, her eyes were filled with tears. “Mom, what's wrong?” I asked. “I'm sorry,” she said, wiping her eyes. “This is only the second gardenia corsage I've ever received. I was given one years ago, long before you kids were born.” “From who?” I asked. “Your father,” Mom said. “He gave me one right before we were engaged.” My eyes locked on Jack's as I blinked away (眨掉) tears. Dad's test? I knew Jack had passed.