(天津卷.4)低温诱导可使二倍体草鱼卵原细胞在减数第一次分裂时不形成纺锤体,从而产生染色体数目加倍的卵细胞,此卵细胞与精子结合发育成三倍体草鱼胚胎。上述过程中产生下列四种细胞,下图所示四种细胞的染色体行为(以二倍体草鱼体细胞含两对同源染色体为例)可出现的是( )
Drivers are warned that it is dangerous to talk on the phone while________.
Research found that children who drank mainly soda were more than twice as likely as those who drank no soda _________ signs of aggression.
that the country leaders can lead them out of the financial problems, people are becoming more optimistic about the future of the country.
—Have you finished your homework? —Not yet. Now I regret the whole afternoon surfing on the Internet.
He can’t tolerate by her again and again during the report, so they quarreled at last.