Stages of Human Development
Problem
What changes occur in a human embryo and fetus during pregnancy?
[Answer is Table 1 and Summary]
Background Information
Pregnancy is divided into three main periods called trimesters, each lasting about 13 weeks. During the first eight to nine weeks of pregnancy, the developing baby is referred to as an embryo. Afterwards, the developing baby is referred to as a fetus.
The first trimester can be divided into even smaller increments called stages. There are 23 stages during the first trimester of pregnancy, each stage lasting from 1 day to 5 days. These stages, studied and defined by embryologist Franklin Paine Mall, provide a framework for the rapid changes an embryo undergoes as it grows.
Materials
- Virtual human embryo web site:
- classroom computer or access to computer lab
- biology textbook
- pencil
Methods
1. Log on to the Web site .
2. You will be assigned a trimester to study in more detail. As you read about the changes that occur to an embryo or fetus during this trimester, answer the questions below and complete Table 1 for your assigned trimester.
a. Indicate on which day(s) or week the event would occur.
b. What major changes to the head occurred during your trimester?
c. How did the developing embryo or fetus change in size during your assigned trimester?
d. Describe the development of major organs such as the heart, liver, kidneys, lungs, etc during your assigned trimester.
e. Describe other changes to the embryo or fetus during your trimester.
Observations
TABLE 1. DEVELOPMENTAL CHANGES DURING PREGNANCY
DEVELOPMENTAL CHANGES DURING THE ______TRIMESTERDay/Week / Head / Size / Organs / Other Changes
Summary
Briefly summarize the development of the embryo or fetus during your assigned trimester.
Analyze and Conclude
1. Identify List and describe the three layers of tissue in the embryo and what each layer of tissue will eventually form in the body.
2. Explain What is the importance of cell differentiation?
3. Infer Why is it important for a mother to eat well and stay healthy during pregnancy?
4. Explain How can changing hormone levels affect a mother's health during and after pregnancy?
Human Development Lab Report Rubric
Complete / Partial / FailData
Data tables are clearly organized and include titles and labels. / 2 / 1 / 0
Data tables are thoroughly completed. / 3 / 2 - 1 / 0
Data is clearly summarized. / 3 / 2 - 1 / 0
Questions: Analyze and Conclude
Identify / 2 / 1 / 0
Explain / 2 / 1 / 0
Infer / 2 / 1 / 0
Explain / 2 / 1 / 0
Report
Name, section, instructor, date, title, neat, accurate spelling of vocabulary words. / 2 / 1 / 0
Total ____/18 = ____%