Development+HW+ZW

=__//Human Life Cycle 16.1 p. 320//__=

23 and 23
 * 1. How many chromosomes does a mother contribute to a new individual? A father?**

Ovaries
 * 2. Where does meiosis occur in males? testes in females?**

The egg is much bigger than the sperm and the sperm swims
 * 3. Compare and egg cell to a sperm cell.**

Meiosis is reduction and the division of cells and mitosis is duplication and division of cells
 * 4. What is the difference between meiosis and mitosis**.

//17.2//


 * 7. Describe the processes involved in development.**
 * Cleavage - their is first a zygote and then it divides into more and more cells and each cells gets the right amount of chromesomes
 * Growth - the daughter cell increase in size
 * Morphogenesis - the embryo begins to assume different shapes
 * Differentiation - cells begins to become specific structures, the nervous system comes first


 * 8. What are the extraembryonic membranes and what is their role?**
 * Chorion - develops into the fetal half of the placenta, provides nourishment
 * Allantois - its like the fetal yoke sack it extends away from the embryo, later gives rise to the urinary bladder
 * Yolk sac - first embryonic membrane to develop, serves as food for the embryo
 * Amnion - enlarges as the embryo enlarges contains fluid to protect the embryo


 * 9. What happens during pre-emrbyonic development?**
 * Ovulation
 * early blastocyst
 * fertilization
 * cleavage
 * implantation
 * morula

First their is just a disk with a yolk, then the umbilical cord forms, and then at 35 days it has a head and a tail region
 * 10. What happens during embryonic development?**


 * 11. What are the primary germ layers and what body structures come from each layer?**
 * Ectoderm - epidermis of skin; lining of oral cavity and rectum; nervous system
 * Mesoderm - skeleton; muscles; urinary system; reproductive system
 * Endoderm - lining of digestive tract and respiratory tract; and the glands of these organs