• Development begins when a sperm fertilizes an egg.

1. How does development begin?
   Answer

• Fertilization

• Development in humans involves certain processes and a set series of stages.
  
  
• The extraembryonic membranes and the placenta allow humans to develop internally within the uterus.
  
  
• Human development is divided into embryonic development (when all systems are established) and fetal development (when systems are completed).

1. Development involves what processes? What are the stages of early development?
   Answer
   
   
2. What are the extraembryonic membranes? What is their function?
   Answer
   
   
3. What is the path of blood through the heart and in the rest of the fetus? Where does exchange take place?
   Answer
   
   
4. What happens during embryonic development? During fetal development?
   Answer

Essential Study Partner

• Preembryonic Development
• Embryonic and Fetal Development

Art Labeling Activity

• Human Extraembryonic Membranes (38.0K)
• Early Development

Art Quiz

• Extraembryonic Membranes

Case Study

• Embryonic Stem Cells-The Future of Organ Transplants

• Male and female sex organs develop from the same indifferent tissue.

1. How do male and female sex organs develop?
   Answer

• Parturition

Art Labeling Activity

• Anatomy of the Breast (36.0K)

• Birth is a multistage process that includes delivery of the child and the extraembryonic membranes.
  
  
• Lactation requires the hormone prolactin, and milk delivery requires the hormone oxytocin.

1. What are the stages of birth and what happens during each stage?
   Answer
   
   
2. How is lactation and milk delivery regulated?
   Answer

• Investigation into aging shows hope of identifying underlying causes of degeneration and prolonging the health span of individuals.

1. What are the different theories of aging?
   Answer
   
   
2. What is the effect of aging on the various systems?
   Answer
   
   
3. What is the best insurance to keep healthy even though aging occurs?
   Answer