11豌豆的花色中紫色对白色为显性。一株杂合紫花豌豆连续自交繁殖三代,则子三代中开紫花的豌豆植株和开白花的豌豆植株的比例是
A.3∶1
B.15∶7
C.9∶7
D.15∶9
开始考试练习点击查看答案12豌豆的腋生花对顶生花显性。以纯合的腋生花豌豆与顶生花豌豆杂交得F<sub>1</sub>,以F<sub>1</sub>自交得F<sub>2</sub>(种子)。理论上说,由这批种子发育而成的植株开花情况是 ( )
A.3/4的植株只有腋生花,1/4的植株只有顶生花
B.每株植株上有3/4为腋生花,1/4为顶生花
C.有的植株只有腋生花,有的植株只有顶生花,有的植株既有腋生花又有顶生花
D.所有植株都既有腋生花又有顶生花,但没有一定的比例
开始考试练习点击查看答案13在豚鼠中,黑色(C)对白色(c)、毛皮粗糙(R)对毛皮光滑(r)是显性。能验证基因的自由组合定律的最佳杂交组合是 ( )
A.黑光×白光→18黑光∶16白光
B.黑光×白粗→25黑粗
C.黑粗×白粗→15黑粗∶7黑光∶16白粗∶3白光
D.黑粗×白光→10黑粗∶9黑光∶8白粗∶11白光
开始考试练习点击查看答案14玉米的基因型与性别对应关系如下表,已知B、b和T、t分别位于两对同源染色体上。<table style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; WIDTH: 89.98%; BORDER-COLLAPSE: collapse; BORDER-TOP: medium none; BORDER-RIGHT: medium none; mso-border-alt: solid black .5pt; mso-yfti-tbllook: 1184; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid black; mso-border-insidev: .5pt solid black" border="1" cellspacing="0" cellpadding="0" width="89%" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 38.8pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes"><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: black 1pt solid; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 11.62%; PADDING-RIGHT: 5.4pt; HEIGHT: 38.8pt; BORDER-TOP: black 1pt solid; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt" width="11%" nowrap="">基因型</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 29.12%; PADDING-RIGHT: 5.4pt; HEIGHT: 38.8pt; BORDER-TOP: black 1pt solid; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt" width="29%" nowrap="">B和T同时存在(<u>B T </u>)</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 32.1%; PADDING-RIGHT: 5.4pt; HEIGHT: 38.8pt; BORDER-TOP: black 1pt solid; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt" width="32%" nowrap="">T存在,B不存在(<u>bbT </u>)</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 27.16%; PADDING-RIGHT: 5.4pt; HEIGHT: 38.8pt; BORDER-TOP: black 1pt solid; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt" width="27%" nowrap="">T不存在(<u>B tt或bbtt</u>)</td></tr><tr style="HEIGHT: 22.4pt; mso-yfti-irow: 1; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: black 1pt solid; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 11.62%; PADDING-RIGHT: 5.4pt; HEIGHT: 22.4pt; BORDER-TOP: #000000; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-top-alt: solid black .5pt" width="11%" nowrap="">性别</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 29.12%; PADDING-RIGHT: 5.4pt; HEIGHT: 22.4pt; BORDER-TOP: #000000; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-top-alt: solid black .5pt" width="29%" nowrap="">雌雄同株异花</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 32.1%; PADDING-RIGHT: 5.4pt; HEIGHT: 22.4pt; BORDER-TOP: #000000; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-top-alt: solid black .5pt" width="32%" nowrap="">雄株</td><td style="BORDER-BOTTOM: black 1pt solid; BORDER-LEFT: #000000; PADDING-BOTTOM: 0cm; BACKGROUND-COLOR: transparent; PADDING-LEFT: 5.4pt; WIDTH: 27.16%; PADDING-RIGHT: 5.4pt; HEIGHT: 22.4pt; BORDER-TOP: #000000; BORDER-RIGHT: black 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-top-alt: solid black .5pt" width="27%" nowrap="">雌株</td></tr></tbody></table>若BbTt的玉米植株做亲本,自交得F<sub>1</sub>代,让F<sub>1</sub>中的雌雄同株异花植株相互交配,则F<sub>2</sub>代中雌、雄株的比例是
A.9∶7
B.3∶1
C.9∶8
D.13∶3
开始考试练习点击查看答案