Wednesday, September 14, 2022
Friday, March 10, 2023
问题:从一个混杂的群体中,按一定标准挑选出彼此相似的优良个体,然后混合...
Wednesday, September 14, 2022
问题:高强度的选择必将导致(),往往降低树木对环境条件的适应性。...
Monday, September 12, 2022
问题:种内变异分那几个层次?在育种中如何利用各层次的变异?...
Wednesday, September 14, 2022
问题:哪些植物适合用一次选择法,哪些植物适合用多次选择法?...
Sunday, September 11, 2022
Wednesday, May 24, 2023
Saturday, October 14, 2023
Sunday, April 21, 2024
问题:在红粒小麦和白粒小麦杂交试验中,当F2分离为红、白两种粒色,其比例为3:1时,说明几对基因在起作用?其比例为15:1时,说明几对基因在起作用?其比例为63:1时,说明几对基因在起作用?...
Saturday, January 20, 2024
问题:通过着丝粒连结的染色单体叫()。A、姐妹染色单体B、同源染色体C、等位基因D、双价染色体...
Wednesday, April 19, 2023
Monday, August 14, 2023
问题:无性繁殖材料退化原因()。A、成熟效应B、位置效应C、临近效应D、病毒侵染...
Thursday, April 11, 2024
Wednesday, September 14, 2022
Sunday, January 22, 2023
Sunday, April 30, 2023
问题:室内切枝授粉适用的树种类型是()。A、种实细小,成熟期短B、树体高大,操作不便C、水培扦插易生根D、对光照要求不高...
Thursday, September 21, 2023
Tuesday, May 23, 2023
Saturday, March 11, 2023