学习了人类性别决定之后,小明很疑惑,没有人为因素,为什么生男生女的机会是均等的呢?于是他决定在班里做一个探究实验来揭开心中疑惑。根据以上内容填空。
组合方式 组别 |
A |
B |
第1组 |
10 |
10 |
第2组 |
8 |
12 |
第3组 |
11 |
9 |
第4组 |
13 |
7 |
第5组 |
9 |
11 |
实验分析:①黑色围棋子模拟的生殖细胞是 ,其中的性染色体的类型是。组合方式A表示所生孩子的性别为,组合方式B表示所生孩子的性别为。
②为避免人为因素的影响,用来装围棋子的袋子应该是 (填“透明的”或是“不透明的”),每完成1次组合,还(填“需要”或“不需要”)摸出的围棋子放回袋内。
Welcome to Sunnyside Hotel! The best hotel for your holiday—Have a good stay! Hotel rules: Please pay before you stay — you can pay cash or with a credit card. We are sorry but guests can't bring animals into the hotel. Please do not smoke in the rooms. Guests can't have visitors in their rooms after ten o'clock at night. We close the front door at 11 in the evening—please don't forget your key. The red key is for the front door. The yellow key is for your room. Meals for today: Breakfast: 7: 00-10: 00 English breakfast; Tea, coffee and juice. Lunch: 12: 30-13: 30 Soup, sandwiches and cake. Dinner: 17: 00-20: 00 Milk, beef and vegetables. Entertainment: Guests can watch television in their rooms at any time. You can also watch television in the TV room in the daytime. This week's entertainment: Monday evening: 19: 00-22: 00 Music in the TV room with Esmeralda, our favourite singer. Wednesday evening: 19: 00-21: 00 Enjoy The Detectives (action film). Swimming pool: Open all summer. Children's playground: Open all year. Wi-Fi access: 24 hours in your room. |
Do you know make a banana milk shake?
( 1 )画出 关于y轴对称的
(其中A1 , B1 , C1分别是A,B,C的对应点)
( 2 )直接写出C , C1两点的坐标;
( 3 )在y轴上找一点P使得PA+PB最小,画出点P所在的位置(保留作图痕迹)