Module 4

1. Module 4

1.2. In this Module

In This Module

Module 4—From Fertilization to Birth

In This Module

Inquiry Question: From fertilization to birth, how is cell differentiation and development regulated by genetic, endocrine, and environmental factors?

There are four lessons in Module 4.

Most of the lessons are designed to take you 80 minutes to complete; however, some lessons may take longer because of the significance of the concept being covered in the lesson. The suggested lesson times do not include the time needed to complete such activities as “Try This,” “Watch and Listen,” assignments, practice questions, review, or research.

This module corresponds to Chapter 15, pages 506 to 543, in your textbook. You may choose to quickly read through these pages for an overview before you begin Module 4.

Module 4 examines the structures, and their functions, and the major events associated with fertilization up to the completion of embryonic development. The characteristics and events associated with fetal development are also examined; from the time directly following embryonic development up to and including birth. Furthermore, the effects of hormones and environmental factors that can have implications for development are also studied. Finally, this module examines the technologies that are available for the enhancement or reduction of reproductive potential.

Lesson 1—Fertilization and Embryonic Development

This lesson describes the process of embryonic development, names the major events, and describes membrane formation that occurs. You will learn to identify the germ layers, state what structures arise from each layer, describe the hormones related to fertilization and pregnancy, and describe how twins are formed.

The following focusing questions are addressed in this lesson:

What are the sequences of events and hormone controls that occur throughout fertilization and embryonic development?

What major tissues and organs arise from the ectoderm, mesoderm, and endoderm?

How are twins formed?

Lesson 2—Fetal Development, Trimester Events, and Environmental Factors

In this lesson you will learn the major events of fetal development related to each of the trimesters and the significance of the first trimester. You will study potentially harmful substances that can cause damage during embryonic and fetal development.

The following focusing questions are addressed in this lesson:

What are the major events of each trimester?
What is the significance of the first trimester?

What is the significance of the effects of teratogens on embryonic and fetal development?

Lesson 3—Hormones and the Birthing Process

In this lesson you will learn to relate the neural and hormonal changes that occur at the end of pregnancy to the physiological effects of the birthing process.

The following focusing questions are addressed in this lesson:

What triggers the birthing process, and what are its stages?

What controls lactation?

Lesson 4—Reproductive Technologies—Enhancing or Reducing Fertility, Monitoring Development, and Use in Parturition

In this lesson you will come to understand how technology can be used to enhance or reduce fertility, monitor fetal development, and assist in parturition.

The following focusing question is addressed in this lesson:

What technologies are used to assist fertilization, to monitor development, and to facilitate parturition?

Module 4 Assessment

Working with a partner or small group that has been approved by your teacher, show your understanding of this module’s content by planning, designing, and creating a multimedia presentation. Make sure you include the following points in your presentation:

Describe all major events and components of prenatal development, from fertilization to the end of the fetal development period, including hormonal control and significant developmental events happening in each trimester.
State and describe three factors that affect embryonic and fetal development. These must include one genetic factor, one hormonal factor, and one environmental factor. For each of these three factors, state how the embryonic germ tissue is affected and how this may or may not affect fetal development.
Examine parturition events and explain the hormonal and neural components that cause the onset of labour and sustain the birthing process through to the end of the placental stage.
Describe the events that need to happen for successful lactation to occur.
Examine reproductive technologies and describe at least one technology that enhances reproductive potential, at least one technology that reduces reproductive potential, and at least one technology that is used to monitor embryonic or fetal development. Be sure to discuss any societal, cultural, environmental, ethical, or economic considerations surrounding the use of these technologies.

Rubric

The following rubric will help you prepare your response. Remember that complete, clearly explained work is necessary when responding to this type of question. The points above are worth 5 marks each, making your presentation worth a total of 25 marks.

Score	Prenatal Development	Affecting Factors	Parturition Events	Lactation	Reproductive Technologies
5 Excellent	Clearly identifies all prenatal development, including where the events are occurring. This includes fertilization and implantation. Has a detailed description of hormonal control. Detailed description of significant developmental events happening in each trimester.	Identifies three factors that affect embryonic and fetal development structures—one of each chromosomal, hormonal, and environmental. Detailed description of how the embryonic germ tissue will be affected. Fully explains how these factors may or may not affect fetal development.	Clearly explains parturition events. Fully describes hormonal and neural components that cause the onset of labour and the changes through to the end of labour.	Fully describes hormonal and neural control of lactation. Fully explains how suckling of baby promotes lactation.	Fully describes each reproductive technology that assists in enhancing reproductive potential, reducing reproductive potential, and monitoring embryonic or fetal development. Describes a concern related to how each societal, cultural, environmental, ethical, and/or economic issue is related to the use of reproductive technologies.
4 Proficient	Clearly identifies most prenatal development and includes where the events are occurring. This includes fertilization and implantation. Has a good description of hormonal control. Has most detailed description of significant developmental events happening in each trimester.	Identifies three factors that affect embryonic and fetal development structures—one of each chromosomal, hormonal, and environmental. Includes a good description of how the embryonic germ tissue will be affected. Explains how these factors may or may not affect fetal development.	Clearly explains parturition events. Describes most of the hormonal and neural components that cause the onset of labour and the changes through to the end of labour.	Describes hormonal and nerve control of lactation. Mostly explains how suckling of baby promotes lactation.	Describes a reproductive technology that assists in enhancing reproductive potential, reducing reproductive potential, and monitoring embryonic or fetal development. Discusses concerns related to at least four of the following— societal, cultural, environmental, ethical, and economic issues related to the use of reproductive technologies.
3 Satisfactory	Identifies some prenatal development and includes where the events are occurring. This includes fertilization and implantation. Has some description of hormonal control. Has some detailed description of significant developmental events happening in each trimester.	Identifies two factors that affect embryonic and fetal development structures—two of either chromosomal, hormonal, or environmental. Includes some description of how the embryonic germ tissue will be affected. Some explanation of how these factors may or may not affect fetal development.	Explains some of the parturition events. Describes some of the hormonal and neural components that cause the onset of labour and the changes through to the end of labour.	Describes only hormonal, not neural, control of lactation. Some explanation of how suckling of baby promotes lactation.	Describes only two of the following—reproductive technologies that assist in enhancing reproductive potential, reducing reproductive potential, and/or monitoring embryonic or fetal development. Discusses concerns related to at least three of following— societal, cultural, environmental, ethical, and/or economic issues related to the use of reproductive technologies.
2 Limited	Lacking much detail of prenatal development, does not include where the events are occurring. Does not include fertilization and implantation. Has limited description of hormonal control. Has limited detailed description of significant developmental events happening in each trimester.	Identifies two factors that affect embryonic and fetal development structures—two of either chromosomal, hormonal, or environmental. Includes limited description of how the embryonic germ tissue will be affected. Has limited explanation of how these factors may or may not affect fetal development.	Names only the parturition events. Limited description of the hormonal and neural components that cause the onset of labour and the changes through to the end of labour.	Describes only some of the hormonal control of lactation, does not describe neural control of lactation. No explanation of how suckling of baby promotes lactation.	Describes only two of the following— reproductive technologies that assist in enhancing reproductive potential, reducing reproductive potential, and/or monitoring embryonic or fetal development. Discusses concerns related to at least two of following— societal, cultural, environmental, ethical, and/or economic issues related to the use of reproductive technologies.
1 Poor	Addresses only one of the bullets at a 2 or 3 level.	Addresses only one of the bullets at a 2 or 3 level.	Addresses only one of the bullets at a 2 or 3 level.	Addresses only one of the bullets at 2 or 3 level.	Addresses only one of the bullets at a 2 or 3 level.