Ở cà chua, gen A: thân cao trội hoàn toàn so với gen a: thân thấp. Cho cây thân cao lai với cây thân cao F1 100% thân cao. Khi cho các cây F1 giao phấn ngẫu nhiên với nhau, ở F2 xuất hiện cả cây thân cao và thân thấp. Tỉ lệ cà chua thân cao thuần chủng có thể có ở đời F2 là bao nhiêu?

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the best answer for the following sentence:

  How _________ have your parents been married?
   

• Choose the correct sentence which is built from the words and phrases given:

  By contrast / the share / oil in total energy consumption / decrease / 95 percent / 80 percent / the same period
  
  

• Choose the best answer for the following sentence:

  What do people ___________ the 25^th wedding anniversary? Is it "silver anniversary"?
   

• Choose one sentence that has the same meaning as the root one:

  The station will be closed for some days because they are replacing the escalators.
  
  

• Choose one sentence that has the same meaning as the root one:

  That woman wrote to me so that I gave her some advice.
  
  

• Choose the best answer for the following sentence:

  Do you ___________ your birthday each year? 

   

• Choose the best answer for the following sentence:

  ___________ would you like to celebrate your birthday, at the day time or in the evening?  

• Choose the best answer for the following sentence:

  Do you ___________ your birthday cake or do you buy it?
   

• Choose the best answer for the following sentence:

  Last night I _________ to my close friend's birthday party.
   

• Choose the best answer for the following sentence:

  There __________ a lot of fruit and drinks at the party yesterday.