Loại đột biến gen nào sau đây không làm thay đổi chiều dài của gen và tỉ lệ giữa các loại nuclêôtit trong gen?

A. Mất 1 cặp nuclêôtit và đảo vị trí giữa 2 cặp nuclêôtit.

B. Thay thế một cặp nuclêôtit bằng một cặp nuclêôtit khác loại.

C. Thay thế một cặp nuclêôtit bằng một cặp nuclêôtit cùng loại.

D.Thêm một cặp nuclêôtit và thay thế cặp nuclêôtit này bằng một cặp nuclêôtit khác.

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 36 to 42.

Scientists have discovered the bones of what may be the largest meat-eating dinosaur ever to walk the earth. The discovery was made by a team of researchers from Argentina and North America in Patagonia, a desert on the eastern slopes of the Andes in South America. Besides the interesting fact that the dinosaur was huge and horrifying, it is even more astounding that the bones of a number of the dinosaurs were found together. This discovery challenges the prior theory that the biggest meat-eaters lived as loners and instead indicates that they may have lived and hunted in packs. The Tyrannosaurus Rex lived in North America and was believed to hunt and live alone.

The newly discovered meat-eater appears to be related to the Giganotosaurus family, being as closely related to it as a fox would be to a dog. It is actually not of the same family at all as the Tyrannosaurus Rex, being as different from it as a cat is from a dog.

The fossilized remains indicate that the animals lived about 100 million years ago. With needle-shaped noses and razor sharp teeth, they were larger than the Tyrannosaurus Rex, although their legs were slightly shorter, and their jaws were designed to be better able to dissect their prey quickly and precisely.

Question 39: The author implies that the most interesting fact about the find is that this dinosaur ___________.

A. was found in the Andes

B. had a powerful jaw and sharp teeth

C. was larger than Tyrannosaurus Rex

D. lived and hunted with others

lộn là 2 cặp nghe đứng bấm câu trả lời của mk, mk xin lỗi

mình còn hổng hiểu nữa mình mới học lớp 5

28 nhé

-1 nghe. đúng 100%

26 nghe

1 cặp nhe

tớ làm cho cậu mấy câu mà không tick thật bất công