1. Module 4

1.20. Module Summary/Assessment

Module Summary and Assessment

Module 4—From Fertilization to Birth

Summary Module Summary

 

In this module you were asked the following inquiry question:

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

From the moment of fertilization through embryonic and fetal development, an amazing transformation occurs in a prenatal organism. The speed at which the changes take place from a single-celled organism to a multicellular organism that is capable of surviving on its own is truly incredible. Once fertilization takes place, the development of the embryo begins. Different layers begin to form, with each of these layers giving rise to more specialized types of tissues and functions. Various membranes support the embryo and help form the placenta which nourishes and supports the fetus. 

 

The development and maintenance of the offspring in utero is controlled by hormones produced by various supporting structures. Once all the major organs and systems are in place, a tremendous amount of growth and maturation of the systems happens. Any time during prenatal development, genetic, hormonal, and environmental factors can affect the developing offspring. However, it is the first three months, specifically the first eight weeks, of development that are most critical. 

 

Hormones initiate the birthing process, resulting in the forceful uterine contractions that expel the fetus and placenta. Once birth has occurred, hormones trigger lactation, or the delivery of milk from the mammary glands. 

 

A myriad of technologies have been developed to control human sexual reproduction. There are technologies that can enhance or reduce reproduction potential, monitor development, and assist in the birthing process. The use of reproductive technology often results in controversy over social and ethical issues. 

 

In this module, the following focusing questions were addressed:

  • 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?

  • 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?

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

  • What controls lactation?

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

To review and summarize the concepts of Module 4, you may wish to complete the Module 4 Concept Organizer. You may have already saved a copy of this document when you first encountered it in the Big Picture section, or you may download it now. It is an outline of the lessons that contains the focusing questions for Module 1. Use the focusing questions to fill in this concept organizer with the ideas that you mastered in each lesson. You can use keywords, point form, or any amount of detail that meets your needs. You may choose to work from the file on your computer, print the document and work from the paper copy, or copy the outline onto a large sheet of poster paper. This is a great tool to review and use for study purposes.

 

Before you begin the Module Assessment, you may want to complete some of the questions on pages 536 and 537 in your textbook as a review. Review questions for all of Unit B can be found on pages 540 to 543 in the textbook. Your teacher can suggest which questions would be best for you to complete and provide you with feedback about your responses.

 

Module Assessment

 

Dividing the prenatal development and parturition events into different periods or stages is a way to gauge normal progress. It is important to remember that not all pregnancies and labours follow these exact time frames. However, you do need to understand the overall progress and relative time periods described. Many factors and technologies can prevent or assist in prenatal development and observation.

 

Work with a partner or small group that has been approved by your teacher to show your understanding of the content in Module 4 by planning, designing, and creating a multimedia presentation that addresses all of the following points.

  1. 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.

  2. State and describe three factors that affect embryonic and fetal development. The three factors must include one genetic factor, one hormonal factor, and one environmental factor. For each of these three factors, state how the embryonic germ tissue will be affected and how this may or may not affect fetal development.

  3. Examine parturition events and explain the hormonal and neural components that cause the onset of labour through to the end of the placental stage.

  4. Describe the events that need to happen for successful lactation to occur.

  5. Examine reproductive technologies by describing at least one technology that enhances reproductive potential, at least one technology that reduces reproductive potential, and one technology that is used to monitor embryonic or fetal development. Discuss any societal, cultural, environmental, ethical, or economic considerations in the use of these technologies.

The following rubric will help you prepare your answer. Remember that complete, clearly explained work is necessary in this type of question. Each question is worth 5 marks, making your presentation worth a total of 25 marks.