** Bố mẹ mang các cặp gen: (Aa, Bb, dd) x (Aa, bb, Dd). Biết mỗi gen quy định một tính trạng trội, lặn hoàn toàn.

Nếu F₁ xuất hiện tỉ lệ kiểu hình 3 : 3 : 3 : 3 : 1 : 1 : 1 : 1, tần số hoán vị gen nếu có nhỏ hơn 50%. Quy luật nào có thể ảnh hưởng đến phép lai?

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Dung dịch X chứa KOH 0,2 M và Ba(OH)₂ 0,1 M. Dung dịch Y gồm H₂SO₄ 0,25M và HCl 0,75M. Thể tích dung dịch X cần vừa đủ để trung hòa 40 ml dung dịch Y là :    

• Read the passage carefully and choose the correct answers
  Marriage nowadays is a choice people make on their own, but this has not always been the case in society. Thousands of years ago, the average lifespan was shorter than it is today. A man usually lived until he was about 40 years old, while women died even sooner because of childbirth. There were many wars and illnesses, and people had to protect themselves by having more children while they were still young. The parents lived through their children.
  Marriage was not so much a romantic love story but a business transaction, or deal. Most marriages were arranged between parents while their children were still very young. It was the custom that the fathers made the decision on whom their children were going to marry. The mothers had little say in it since they rarely made any decisions outside the household. The fathers would meet to arrange the wedding date and the money given for the bride on her wedding date. The more money and land a girl had, the more chances she had to marry well. Therefore, it was important that her father choose the bridegroom very well. Usually, it was someone who came from a good family or who was rich too. It was very unlikely that people married outside their social class. A few well-off and rich merchants got to marry poorer noblewomen and became King’s business advisors. In a way, poor peasants had an easier choice as it was less important whom they married.
  The practice of arranged marriage is still common in some countries in the Middle East, such as India or Pakistan. Here, social classes are still strongly divided and very well-kept. Often, however, arranged marriages are a sign that people do not want to let go of the past, which gives them comfort and security in an ever-changing world.
  (Adapted from Longman Essence Reading, Vol. 2)
  Question. The word "it" in paragraph 1 refers to ______.
  

• 0ur chairman hasn’t come yet. If he _______on time, we have to put off the meeting.

• Điều kiện để chất mới ra đời là gì?

• Hai trung tâm dịch vụ lớn nhất của Nga là
  

• Hai lò xo có khối lượng không đáng kể, độ cứng lần lượt là và được mắc song song nhau. Độ cứng của hệ hai lò xo ghép trên là  

• Cho hàm số Đồ thị hàm số  như hình vẽ bên dưới.   Có bao nhiêu giá trị nguyên của tham số để hàm số có điểm cực trị ?

• Our English lessons are ________ longer than other subjects’ lessons.

• Sản lượng lương thực của Trung Quốc cao nhất thế giới, nguyên nhân chủ yếu là do

• Để hợp tác tốt ta phải biết: