depends on if xy style or zw style

depends on if xy style or zw style

所有跟贴·加跟贴·新语丝读书论坛

送交者: qtl 于 2010-01-06, 14:08:28:

回答: 卵子大得多，含有营养物质，不会动，只有一种性染色体。精子有两种由方舟子于 2010-01-06, 13:04:47:

usually birds has only one egg type, two types of sperm;