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44.1 Early Developmental Stages
  • Development begins when a sperm fertilizes an egg.
  • The first stages of embryonic development in animals lead to the establishment of the embryonic germ layers.
  • The presence of yolk affects the manner in which animal embryos go through the early developmental stages.
  • In vertebrates, the nervous system develops above the notochord after formation of a neural tube.
  1. What is fertilization?
  2. What happens at the surface of an egg once fertilization has occurred that prevents the penetration of other sperm?
  3. Cell division without cell growth in the embryo is called _________________.
  4. What is the difference between morula and blastula stages?
  5. How do endoderm and ectoderm develop and during what stage does this occur?
  6. From which tissue layers are the notochord and nervous systems of vertebrates derived?
Essential Study Partner Summaries of major points
  1. Fertilization
  2. Embryonic development
  3. The effect of yolk
  4. Neurulation and the nervous system
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44.2 Developmental processes
  • Cytoplasmic segregation and induction help bring out cellular differentiation and morphogenesis.
  • Development genetics has benefited from research into the development of Caenorhabditis elegans, a roundworm, and Drosophilia melanogaster, a fruit fly.
  • Homeotic genes are involved in shaping the outward appearance of animals.
  1. What are cellular differentiation and morphogenesis?
  2. The ability of one embryonic tissue to affect the development of another is called ____________.
  3. What is apoptosis and how does it function in development?
  4. What is the function of homeotic genes?
Essential Study Partner Summaries of major points
  1. Development requires growth, differentiation, and morphogenesis
  2. Induction
  3. Model organisms
Art Quizzes
44.3 Human embryonic and fetal development
  • Humans, like chicks, are dependent upon extraembryonic membranes that perform various services that contribute to development.
  • During the embryonic period of human development, all systems appear.
  • Humans are placental mammals; the placenta is a unique organ where exchange between fetal blood and mother's blood takes place.
  • During fetal development, the fetus grows large enough to live on its own. Birth is a multistage process that includes delivery of the child and the extraembryonic membranes.
  1. What occurs during the embryonic and fetal periods of development?
  2. What produces human chorionic gonadotropin and what does it do?
  3. During what week of development do limb buds appear?
  4. What is the function of the placenta?
Essential Study Partner Summaries of major points
  1. Development covers events from fertilization to parturition
  2. Human development is divided into...
  3. Extraembryonic membranes
  4. Embryonic development
  5. Structure and function of the placenta
  6. Fetal development and birth
  7. Stages of birth
Art Quizzes

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