Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for eac...

LQ

Lê Quỳnh Anh

2 tháng 11 2017

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of...

Đọc tiếp

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes.

These trails incorporate no directional information and may be followed by other ants in either direction. Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, why do ants use different compounds as trail pheromones?

A. To reduce their sensitivity to some chemicals

B. To attract different types of ants

C. To protect their trail from other species

D. To indicate how far away the food is

#Mẫu giáo

1

DH

Dương Hoàn Anh

2 tháng 11 2017

C

Theo đoạn văn này, tại sao kiến lại sử dụng các hợp chất khác nhau như dấu vết pheromones?

A. Để giảm độ nhạy cảm của chúng đối với một số hóa chất

B. Thu hút các loại kiến khác nhau

C. Để bảo vệ dấu vết của chúng khỏi các loài khác

D. Để chỉ ra cách thức ăn bao xa

=> đáp án C

Thông tin: a food trail has to be kept secret from members of other species.

Đúng(0)

LQ

Lê Quỳnh Anh

21 tháng 11 2019

Read the following passage and mark the letter A, B, C or B on your answer sheet to indicate the correct answer to each of the questions from 30 to 37. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny...

Đọc tiếp

Read the following passage and mark the letter A, B, C or B on your answer sheet to indicate the correct answer to each of the questions from 30 to 37.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes.

These trails incorporate no directional information and may be followed by other ants in either direction. Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth. The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, why do ants use different compounds as trail pheromones?

A. To reduce their sensitivity to some chemicals

B. To attract different types of ants

C. To protect their trail from other species

D. To indicate how far away the food is

#Mẫu giáo

1

DH

Dương Hoàn Anh

21 tháng 11 2019

Đáp án C

Theo đoạn văn này, tại sao kiến lại sử dụng các hợp chất khác nhau như dấu vết pheromones?

A. Để giảm độ nhạy cảm của chúng đối với một số hóa chất

B. Thu hút các loại kiến khác nhau

C. Để bảo vệ dấu vết của chúng khỏi các loài khác

D. Để chỉ ra cách thức ăn bao xa

Dẫn chứng: a food trail has to be kept secret from members of other species.

Đúng(0)

LQ

Lê Quỳnh Anh

21 tháng 9 2019

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of...

Đọc tiếp

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, why do ants use different compounds as trail pheromones?

A. To reduce their sensitivity to some chemicals

B. To attract different types of ants

C. To protect their trail from other species

D. To indicate how far away the food is

#Mẫu giáo

1

DH

Dương Hoàn Anh

21 tháng 9 2019

Đáp án C

Dịch: Theo bài văn, tại sao những chú kiến lại sử dụng những hợp chất khác nhau cho vệt pheromones?

A. Để giảm sự nhạy bén, thích ứng với một vài chất hóa học

B. Để thu hút nhiều loài kiến hơn

C. Để bảo vệ vệt của chúng khỏi những loài khác

D. Để báo hiệu thức ăn cách bao xa Thông tin nằm ở đoạn 2: Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. (Không giống những thông điệp khác, chẳng hạn như thông điệp từ một con kiến đã chết, đường dấu thức ăn phải được giữ bí mật khỏi thành viên của những loài kiến khác. Cũng không có chuyện gì ngạc nhiên rằng loài kiến sử dụng những hợp chất khác nhau trong đường dấu pheromones).

Đúng(0)

LQ

Lê Quỳnh Anh

14 tháng 11 2018

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger on the ground and depositing a tiny amount of trail...

Đọc tiếp

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger on the ground and depositing a tiny amount of trail pheromone - a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Attatexana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, why do ants use different compounds as trail pheromones?

A. To protect their trail from other species.

B. To reduce their sensitivity to some chemicals.

C. To attract different types of ants.

D. To indicate how far away the food is.

#Mẫu giáo

1

DH

Dương Hoàn Anh

14 tháng 11 2018

A

Thông tin ở câu đầu của đoạn số 2: “a food trail has to be kept secret from members of other species.”: dấu vết thức ăn phải được giữ bí mật với các thành viên của loài khác = A. To protect their trail from other species.

Đúng(0)

LQ

Lê Quỳnh Anh

20 tháng 3 2019

Read the following passage and mark the letter A, 8, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of...

Đọc tiếp

Read the following passage and mark the letter A, 8, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone - a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space.

The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

Question 39: According to the passage, why do ants use different compounds a trail pheromones?

A. To reduce their sensitivity to some chemicals

B. To indicate how far away the food is

C. To attract different types of ants

D. To protect their trail from other species

#Mẫu giáo

1

DH

Dương Hoàn Anh

20 tháng 3 2019

Đáp án D

Theo đoạn văn này, tại sao kiến lại sử dụng các hợp chất khác nhau như dấu vết pheromones?

A. Để giảm độ nhạy cảm của chúng đối với một số hóa chất

B. Để chỉ ra cách thức ăn bao xa

C. Thu hút các loại kiến khác nhau

D. Để bảo vệ dấu vết của chúng khỏi các loài khác

Thông tin: a food trail has to be kept secret from members of other species.

Đúng(0)

LQ

Lê Quỳnh Anh

14 tháng 6 2018

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of...

Đọc tiếp

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes.

These trails incorporate no directional information and may be followed by other ants in either direction. Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, how are ants guided by trail pheromones?

A. They concentrate on the smell of food

B. They follow an ant who is familiar with the trail

C. They avoid the vapor spaces by moving in a straight line

D. They sense the vapor through their antennae

#Mẫu giáo

1

DH

Dương Hoàn Anh

14 tháng 6 2018

D

Theo đoạn văn, kiến được hướng dẫn bằng pheromone như thế nào?

A. chúng tập trung vào mùi thức ăn.

B. chúng đi theo một con kiến quen thuộc với dấu vết

C. chúng tránh không gian hơi bằng cách di chuyển theo một đường thẳng.

D. chúng có thể cảm nhận hơi qua ăngten của chúng.

=> đáp án D

Đúng(0)

LQ

Lê Quỳnh Anh

11 tháng 12 2018

Read the following passage and mark the letter A, B, C or B on your answer sheet to indicate the correct answer to each of the questions from 30 to 37. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny...

Đọc tiếp

Read the following passage and mark the letter A, B, C or B on your answer sheet to indicate the correct answer to each of the questions from 30 to 37.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes.

These trails incorporate no directional information and may be followed by other ants in either direction. Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth. The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, how are ants guided by trail pheromones?

A. They concentrate on the smell of food.

B. They follow an ant who is familiar with the trail

C. They avoid the vapor spaces by moving in a straight line.

D. They sense the vapor through their antennae.

#Mẫu giáo

1

DH

Dương Hoàn Anh

11 tháng 12 2018

Đáp án D

Theo đoạn văn, kiến được hướng dẫn bằng pheromone như thế nào?

A. chúng tập trung vào mùi thức ăn.

B. chúng đi theo một con kiến quen thuộc với dấu vết

C. chúng tránh không gian hơi bằng cách di chuyển theo một đường thẳng.

D. chúng có thể cảm nhận hơi qua ăngten của chúng.

Đúng(0)

LQ

Lê Quỳnh Anh

5 tháng 1 2018

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of...

Đọc tiếp

Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, how are ants guided by trail pheromones?

A. They concentrate on the smell of food.

B. They follow an ant who is familiar with the trail

C. They avoid the vapor spaces by moving in a straight line.

D. They sense the vapor through their antennae.

#Mẫu giáo

1

DH

Dương Hoàn Anh

5 tháng 1 2018

Đáp án D

Dịch: Theo bài viết, kiến được dẫn dắt bởi đường dấu pheromones như thế nào?

A. Chúng tập trung vào mùi vị thức ăn.

B. Chúng đi theo một con kiến mà đã quen thuộc với đường dấu.

C. Chúng tránh những khoảng không có khí đó bằng cách di chuyển theo một đường thẳng.

D. Chúng cảm nhận khí hơi đó qua ăng-ten.

Thông tin nằm ở đoạn 3: The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. (Chất bay hơi pheromones ở ngay trên đường dấu sẽ dẫn dắt con kiến đi dọc theo đường, và kiến sẽ phát hiện ra dấu hiệu bằng bộ phận thụ thể ở ăng-ten)

Đúng(0)

LQ

Lê Quỳnh Anh

11 tháng 8 2017

Read the following text and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questionsMany ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone –...

Đọc tiếp

Read the following text and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space.

The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, why do ants use different compounds a trail pheromones?

A. To reduce their sensitivity to some chemicals

B. To indicate how far away the food is

C. To attract different types of ants

D. To protect their trail from other species

#Mẫu giáo

1

DH

Dương Hoàn Anh

11 tháng 8 2017

D

Kiến thức: Đọc hiểu

Giải thích:

Theo đoạn văn này, tại sao kiến lại sử dụng các hợp chất khác nhau như dấu vết pheromones?

A. Để giảm độ nhạy cảm của chúng đối với một số hóa chất

B. Để chỉ ra cách thức ăn bao xa

C. Thu hút các loại kiến khác nhau

D. Để bảo vệ dấu vết của chúng khỏi các loài khác

Thông tin: a food trail has to be kept secret from members of other species.

Đúng(0)

LQ

Lê Quỳnh Anh

21 tháng 12 2017

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions. Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger on the ground and depositing a tiny amount of trail...

Đọc tiếp

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger on the ground and depositing a tiny amount of trail pheromone - a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Attatexana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

According to the passage, how are ants guided by trail pheromones?

A. They sense the vapor through their antennae.

B. They avoid the vapor spaces by moving in a straight line.

C. They follow an ant who is familiar with the trail.

D. They concentrate on the smell of food.

#Mẫu giáo

1

DH

Dương Hoàn Anh

21 tháng 12 2017

A

Thông tin ở câu đầu đoạn 3: “the ant detects this signal with receptors in its antennae.”: Kiến phát hiện ra tín hiệu nhờ cơ quan thụ cảm ở trong râu = They sense the vapor through their antennae.

Đúng(0)

Chúng tôi đề xuất

Tài nguyên

Ứng dụng mobile

Bảng xếp hạng

Các khóa học có thể bạn quan tâm

Yêu cầu VIP