All organic molecules have permanent dipole.

All of the cells in a particular plant start out with the same complement of genes. How then can these cells differentiate and form. structures as different as roots, stems, leaves,and fruits? The answer is that only a small subset of the genes in a particular kind of cell are expressed,or turned on,at a given time. This is accomplished by a complex system of chemical messengers that in plants include hormones and other regulatory molecules. Five major hormones have been identified: auxin, abscisic acid ,cytokinin ,ethylene ,and gibberellin. Studies of plants have now identified a new class of regulatory molecules called oligosaccharins. Unlike the oligosaccharins,the five well-known plant hormones are pleiotropic rather than specifie, that is, each has more than one effect on the growth and development of plants. The five have so many simultaneous effects that they are not very useful in artificially controlling the growth of crops. Auxin, for instance, stimulates the rate of cell elon-gation(使伸长),causes shoots to grow up and roots to grow down, and inhibits the growth of lateral shoots. Auxin also causes the plant to develop a vascular system, to form. lateral roots,and to produce ethylene. The pleiotropy of the five well-studied plant hormones is somewhat analogous to that of certain hormones in animal. For example, hormones from the hypothalamus(下丘脑)in the brain stimulate the anterior lobe of the pituitary gland to synthesize and release many different hormones , one of which stimulates the release of hormones from the adrenal cor-tex(肾上腺皮质). These hormones have specific effects on target organs all over the body.One hormone stimulates the thyroid gland, for example,another the ovarian follicle cells,and so forth. In other words, there is a hierarchy of hormones. Such a hierarchy may also exist in plants. Oligosaccharins are fragments of the cell wall released by enzymes(酶);different enzymes release different oligosaccharins.There are indications that pleiotropic plant hormones may actually function by activating the enzymes that release these other, more specific chemical messengers from the cell wall.

The five well-known plant hormones are not useful in controlling the growth crops because_____.

A.it is not known exactly what functions the hormones perform

B.each hormone has various effects on plants

C.none of the hormones can function without the others

D.each hormone has different effects on different kinds of plants

The passage that the place of hypothalamic hormones in the hormonal hierarchies of animals is similar to the place of____.A.plant cell walls

B.the complement of genes in each plant cell

C.a subset of a plant cell’s gene complement

D.the five major hormones

Which of the follow is a function like to be performed by an oligosaccharinA.To stimulate a particular plant cell to become part of a plant’s root system,

B.To activate enzymes that release specific chemical messengers from plan cell walls.

C.To duplicate the Kcnc complement in a particular pUnt coll.

D.To produce multiple effects on a particular subsystem of plant cells.

The author mentions specific effects that auxin on plam development in order to iilustrate the ______.A.way in which hormones arc produced by plant

B.hierarchical nature of the functioning of plant hormones

C.differenecs between the best-known plant hormones

D.concept of pleiotropy as it is exhibited by plant hormones

请帮忙给出每个问题的正确答案和分析，谢谢！

All of the cells in a particular plant start out with the

same complement of genes. How then can these cells

differentiate and form. structures as different as roots,

stems, leaves, and fruits? The answer is that only a

(5) small subset of the genes in a particular kind of cell are

expressed, or turned on, at a given time. This is accom-

plished by a complex system of chemical messengers

that in plants include hormones and other regulatory

molecules. Five major hormones have been identified:

(10) auxin, abscisic acid, cytokinin, ethylene, and gibberel-

lin. Studies of plants have now identified a new class of

regulatory molecules called oligosaccharins.

Unlike the oligosaccharins, the five well-known plant

hormones are pleiotropic rather than specific, that is,

(15) each has more than one effect on the growth and devel-

opment of plants. The five has so many simultaneous

effects that they are not very useful in artificially

controlling the growth of crops. Auxin, for instance,

stimulates the rate of cell elongation, causes shoots to

(20) grow up and roots to grow down, and inhibits the

growth of lateral shoots. Auxin also causes the plant to

develop a vascular system, to form. lateral roots, and to

produce ethylene.

The pleiotropy of the five well-studied plant

(25) hormones is somewhat analogous to that of certain

hormones in animal. For example, hormones from the

hypothalamus in the brain stimulate the anterior lobe

of the pituitary gland to synthesize and release many

different hormones, one of which stimulates the release

(30) of hormones from the adrenal cortex. These hormones

have specific effects on target organs all over the body.

One hormone stimulates the thyroid gland, for

example, another the ovarian follicle cells, and so forth.

In other words, there is a hierarchy of hormones.

(35) Such a hierarchy may also exist in plants. Oligosac-

charins are fragments of the cell wall released by

enzymes: different enzymes release different oligosac-

charins. There are indications that pleiotropic plant

hormones may actually function by activating the

(40) enzymes that release these other, more specific chemical

messengers from the cell wall.

According to the passage, the five well-known plant hormones are not useful in controlling the growth of crops because______

A．it is not known exactly what functions the hormones perform

B．each hormone has various effects on plants

C．none of the hormones can function without the others

D．each hormone has different effects on different kinds of plants

E．each hormone works on only a small subset of a cell’s genes at any particular time

All of the following are advantages of partnership except

A．it is relatively easy to organize and dissolve.

B．the partners are subject to less regulations.

C．the partners have unlimited liability.

D．the partners can identify themselves with the association.

All of the plants nowraised on farms have been developed from plants once grew wild.

A B C D

4 All organisations require trained employees. However, training can take many forms, some of which are internal to the organisation.

Required:

Explain what is meant by the terms:

(a) Computer based training. (3 marks)

A firewall is a(68)system designed to(69)all organization, s network against threats.

A．operating

B．programming

C．security

D．service

●A firewall is a (68) system designed to (69) all organization,s network aga-inst threats.

(68) A．operating

B．programming

C．security

D．service

(69) A．prevent

B．protect

C．develop

D．exploit

Effective communication is essential for all organizations. It links the activities of the various parts of the organization and ensures that everyone is working toward a common goal. It is also extremely important for motivating employees. Staff need to know how they are getting on, what they are doing right and in which areas they could improve. Working alone can be extremely difficult and it is much easier if someone takes an interest and provides support. Employees need to understand why their job is important and how it contributes to the overall success of the firm. Personal communication should also include target setting. People usually respond well to goals, provided these are agreed between the manager and subordinate and not imposed.

However, firms often have communications problems that can undermine their performance. In many cases, these problems occur because messages are passed on in an inappropriate way. There are, of course, several Ways of conveying information to others in the organization. These include speaking to them directly, e-mailing, telephoning or sending a memo. The most appropriate method depends on example, anything that is particularly sensitive or confidential, such as an employee's appraisal, should be done face-to-face.

One of the main problems for senior executives is that they do not have the time or resources needed to communicate effectively. In large companies, for example, it is impossible for senior managers to meet and discuss progress with each employee individually. Obviously this task can be delegated but at the cost of creating a gap between senior management and staff. As a result, managers are often forced to use other methods of communication, like memos or notes, even if they know these are not necessarily the most suitable means of passing on messages.

The use of technology, such as e-mail, mobile phones and network systems, is speeding up communication immensely. However, this does not mean that more investment in technology automatically proves beneficial: system can become outdated or employees may lack appropriate training. There are many communications tools now available but a firm cannot afford all of them. Even if it could, it does not actually need them all. The potential gains must be weighed up against the costs, and firms should realize that more communication does not necessarily mean better communication.

As the number of people involved in an organization increases, the use of written communication rises even faster. Instead of a quick conversation to sort something out numerous messages can be passed backwards and forward. This can lend to a tremendous amount of paperwork and is often less effective than face to face communication. When you are actually talking to someone you can discuss things until you are happy they have understood and feedback is immediate. With written messages, however, you are never quite sure how it will be received. What you think you have said and what the other person thinks you have said can be very different.

The amount of written information generated in large organization today can lead to communication overload. So much information is gathered that it gets in the way of making decisions. Take a look at the average manager's desk and you will see the problem—it is often covered in letter, reports and memos. This overload can lead to inefficiencies. For example, managers may not be able to find the information they want when they need it. Communication is also becoming more difficult with the changes occurring in employment patterns. With more people working part-time and working from home, managing communication is becoming increasingly complex.

Effective communication is essential for organizations in that ______.

A．it makes everyone in the organization work together towards a common goal

B．it makes staff know how they are getting on

C．employees need to understand why their job is important

D．it makes staff know if they are doing right

Effective communication is essential for all organisations. It links the activities of the various parts of the organisation and ensures that everyone is working towards a Common goal. It is also extremely important for motivating employees. Staff need to know how they are getting on, what they are doing right and in which areas they could improve. Working alone can be extremely difficult and it is much easier if someone takes an interest and provides support. Employees need to understand why their job is important and how it contributes to the overall success of the firm. Personal communication should also include target setting. People usually respond well to goals, provided these are agreed between the manager and subordinate and not imposed.

However, firms often have communications problems that can undermine their performance. In many cases, these problems occur because messages are passed on in an inappropriate way. There are of course, several ways of conveying information to others in the organisation. These include speaking to them directly, e-mailing, telephoning or sending a memo. The most appropriate method depends on what exactly it is you are communicating. For example, anything that is particularly sensitive or confidential, such as an employee's appraisal, should be done face-to-face.

One of the main problems for senior executives is that they do not have the time or resources needed to communicate effectively. In large companies, for example, it is impossible for senior managers to meet and discuss progress with each employee individually. Obviously this task can be delegated but at the cost of creating a gap between senior management and staff. As a result, managers are often forced to use other methods of communication. Like memos or notes, even if they know these are not necessarily the most suitable means of passing on messages.

The use of technology, such as e-mail, mobile phones and network system, is speeding up communication immensely. However, this does not mean that more investment in technology automatically proves beneficial, systems can become outdated or employees may lack appropriate training. There are many communications tools now available but a firm cannot afford all of them. Even if it could, it does not actually need them all. The potential gains must be weighed up against the costs, and firms should realise that more communication does not necessarily mean better communication.

As the number of people involved in an organisation increase, the use of written communication rises even faster. Instead of a quick conversation to sort something out numerous messages can be passed backwards and forwards. This can lead to a tremendous amount of paperwork and is often less effective than face to face communication. When you are actually talking to someone you can discuss things until you are happy they have understood and feedback is immediate. With written messages, however, you are never quite sure how it will be received. What you think you have said and what the other person thinks you have said can be very different.

The amount of written information generated in large organisations today can lead to communication overload. So much information is gathered that it gets in the way of making decisions. Take a look at the average manager's desk and you will see the problem—it is often covered in letters, reports and memos. This overload can lead to inefficiencies. For example, managers may not be able to find the information they want when they need it. Communication is also becoming more difficult with the changes occurring in employment patterns. With more people working part-time and working from home, managing communication is becoming increasingly complex.

According to the writer, the best way of achieving effective communication is to______.

A．adapt the message to suit a particular audience

B．make the content of message brief and direct

C．select the most suitable means of conveying a particular message

D．ensure that information is targeted at the appropriate group of people

All of the plants now raised on farms have been developed from plants ______ in the wild.

A．once they grew

B．that once grew

C．they grew once

D．once grew