Ở chuột, hai cặp gen quy định 2 cặp tính trạng về nàu lông và hình dạng đuôi nằm trên NST thường phân li độc lập với nhau. Khi cho giao phối hai dòng chuột thuần chủng lông xám, đuôi cong với lông trắng, đuôi thẳng: a, Lập sơ đồ lai Từ P đến F1 b, Tiếp tục cho giao phối giữa F1 với chuột khác thu được F2 có kết quả như sau: - 37,5% chuột lông xám, đuôi cong - 37,5% chuột lông xám, đuôi thẳng - 12,5% chuột lông trắng, đuôi cong - 12,5% chuột lông trắng, đuôi thẳng Giải thích kết quả và lập sơ đồ lai của F1. ( Biết lông xám, đuôi cong trội hoàn toàn so với lông trắng, đuôi thẳng )

Các câu hỏi liên quan

1. Write questions and short answer about the food. Use the correct form of there is or there are and some, or any. Follow the examples. Example : bananas ? / Yes. A : Are there any bananas ? B : Yes, there are some cheese ? / No. A : Is there any cheese ? B : No, there isn't any. 1. cakes ? / Yes.__________________________________________ 2. butter ? / No.__________________________________________ 3. mineral water ? / Yes.___________________________________ 4. eggs ? / No.____________________________________________ 5. salt ? / Yes.___________________________________________ 6. carrots ? / Yes._______________________________________ 7. apples ? / Yes.__________________________________________ 8. sugar ? Yes._____________________________________________ 2. Fill in each blank with the correct word : some, or any. Mai : I'm really hungry. What did you have for lunch ? Nam : Nothing ! I wanted to make (1)________pancakes but I don't know how to make one. Mai : OK. We can have (2)_________pancakes. Is there (3)________flour and cooking oil ? Nam : Yes, and we have (4)_______eggs too. Mai : Good. I need two eggs for each pancake. I want (5)________turmeric too. Nam : Yes, there is (6)__________for you. Do you need (7)________minced pork and green onions ? Mai : Yes, I need (8)_________.OK, that's enough for us to make pancakes now. 3. Match the two parts of the sentences, and write the answer ( a - b ) in the blanks. _______1. How much a. food at the party ? _______2. There's a lot b. onions _______3. There aren't many c. orange juice _______4. How many d. of tomatoes in this salad. _______5. We don't have much e. milk do we have. _______6. Was there much g. of ham on this pizza. _______8. Are there many h. potatoes do you want ? 4. Complete the questions with " How much " or " How many ". 1._______________homework do you do a day ? 2. ______________sleep do you get a night ? 3._______________text messages do you send a day ? 4._______________money have you got in your pocket ? 5._______________cousins have you got ? 6._______________packets of biscuits do you eat a week ? 7._______________people are there in this classroom ? 8._______________time is there to the end of the lesson ?