题目

某二倍体植物的体细胞含有44条染色体，此生物体中某分裂期的细胞中存在姐妹染色单体，下列对该细胞的判断，不正确的是( ) A．可处于减数第二次分裂前期 B．染色体数目可达88条 C．可发生交叉互换现象 D．细胞中核DNA数目可能是44个 答案：B 该二倍体植物的体细胞含有44条染色体，则其有丝分裂后期染色体为88条，此时不存在姐妹染色单体。减数第二次分裂前期存在姐妹染色单体，有22条染色体。减数第一次分裂前期发生交叉互换，此时也存在姐妹染色单体，有44条染色体。减数第二次分裂前期、中期有44个核DNA分子，此时也存在姐妹染色 The Longest Bicycle The longest true bicycle was 28.1 meters long and had two wheels. It was built by the students at the  Delft  University  of Technology  in  the Netherlands. The bicycle was ridden more than 100 meters in Delft on December 11, 2002.  The Most Expensive Jeans A pair of Levis jeans which was over 115 years old then was sold by Randy Knight to a Japanese buyer over the Internet on June 15, 2005. The jeans cost the buyer $60,000. The Heaviest Apple The heaviest apple weighed 1.849 kilos. It was grown by Chisato Iwasaki on his apple farm in Japan. Chisato picked the apple on October 24, 2005.                                    The Largest Mobile Phone The Iargest mobile phone was the Sony Ericsson W810i. It was 2.50×1.14×0.49m and was measured (量) at the MTN Scien Centre in Cape Town, South Africa, on September 20, 2007. 1.The longest bicycle ______. A. was made in the USA. B. couldn't be ridden C. was about 100 meters long D. had only two wheels 2.Which of the following is NOT true about the most expensive pair of jeans? A．It was sold over the Internet. B．It cost the buyer $60,000. C．It was sold to an American buyer. D．It is more than 100 years old now. 3.According to the passage, what happened on October 24, 2005? A．The heaviest apple was grown. B．The longest bicycle was built. C．The largest mobile phone was made. D．The heaviest apple was picked.