Cho các phát biểu sau:

(1) Sự nhân đôi của NST dẫn đến sự nhân đôi của ADN.

(2) Sự trao đổi đoạn tương đồng giữa 2 cromatit khác nguồn trong cặp tương đồng sẽ luôn dẫn đến hiện tượng hoán vị gen giữa 2 locut gen nằm trên NST đó.

(3) Người nam Claiphentơ mang 2 NST X chứa alen bệnh về locut gen quy định bệnh mù màu xanh lục – đỏ thì sẽ bị mù màu nhẹ hơn so với người nam chỉ có 1 NST X mang alen bệnh.

(4) Hoán vị gen là một trường hợp đặc biệt của đột biến chuyển đoạn NST.

Có bao nhiêu phát biểu sai?

A. 1      

B. 2 

C. 3  

D. 4

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of the primary stress in each of the following questions.

A. certificate               

B. compulsory             

C. undergraduate        

D. curriculum

Read the following text then answer the questions that followed by circling its corresponding letter marked A, B, C or D from 43 to 50.

Since water is the basis of life, composing the greater part of the tissues of all living things, the crucial problem of desert animals is to survive in a world where sources of flowing water are rare. And since man’s inexorable necessity is to absorb large quantities of water at frequent intervals, he can scarcely comprehend that many creatures of the desert pass their entire lives without a single drop. Uncompromising as it is, the desert has not a limited life but only those forms unable to withstand its desiccating effects. No moist skinned, water-loving animals can exist there. Few large animals are found. The giants of the North American desert are the deer, the coyote, and the bobcat. Since desert country is open, it holds more swift-footed running and leaping creatures than the tangled forest. Its population is largely nocturnal, silent, filled with reticence, and ruled by stealth. Yet they are not emaciated. Having adapted to their austere environment, they are as healthy as animals anywhere else in the world. The secret of their adjustment lies in the combination of behavior and physiology.

None could survive, like mad dogs and Englishmen, if they went out in the midday sun, many would die in a matter of minutes. So most of them pass the burning hours asleep in cool, humid burrows underneath the ground, emerging to hunt only by night. The surface of the sun-baked desert averages around 150 degrees, but 18 inches down the temperature is only 60 degrees.

According to the passage, one characteristic of animals living in the desert is that ________. 

A. they live in an accommodating environment

B. they can hunt in temperature of 150 degrees

C. they are smaller and fleeter than forest animals

D. they are less healthy than animals living in other places

Hỗn hợp X gồm metyl metacrylat, axit axetic, axit benzoic. Đốt cháy hoàn toàn a gam X, thu được 0,38 mol CO₂ và 0,29 mol H₂O. Mặt khác, a gam X phản ứng vừa đủ với dung dịch NaOH, thu được 0,01 mol ancol và m gam muối. Giá trị của m là

A. 12,02

B. 25,00

C. 12,16

D. 11,75

Cho dãy các chất: axit axetic, etyl axetat, anilin, ancol etylic, phenol, ancol benzylic. Số chất trong dãy phản ứng được với dung dịch NaOH là

A. 5

B. 4

C. 2

D. 3