根据短文内容，完成下面各题，每空词数不限 
My English teacher is Mary. She is from England. Her father is Nick and her mother is Rose. They are very old. So they don’t work now. Mary has two children, a son and a daughter. Her daughter is Betty. Her son is John. Mary and her daughter are in China, but her husband Paul Smith is in England. Her son is in America. Paul is a police officer. John is a college student. Betty and I are in the same school. We are classmates. We are in Class Three, Grade Seven.
Betty is Mary’s____ .
Betty’s father is a ____  (职业).
____ teaches the writer(作者) English.
Mary comes from ____  .
Nick and Rose are Mary’s ____  .

女娄菜是一种雌雄异株的二倍体植物，其花色遗传由两对等位基因A和a、B和b共同控制（如图甲所示）．其中基因A和a位于常染色体上，基因B和b在性染色体上（如图乙所示）．请据图回答：

（1）据图乙可知，在减数分裂过程中，X与Y染色体能发生交叉互换的区段是____ ．

（2）开金黄色花的雄株的基因型有AAX^bY或____ ，绿花植株的基因型有____ 种．

（3）某一白花雌株与一开金黄色花雄株杂交所得F₁都开绿花，请用遗传图解进行推导该交配结果（要求写出配子）

____ 

下列关于造血干细胞和其分化形成的B细胞的叙述，正确的是（   ）