[1] Quiz 1

• Process of gamete formation involving meiotic cell division

  Gametogenesis
• Gametogenesis involves the meiotic cell division of:

  Spermatozoa and ovum
• Process where male gametes are formed

  Spermatogenesis
• Another term for the male gamete

  Spermatozoon
• Process of the formation of eggs

  Oogenesis
• Germ cells become oogonia during oogenesis
• Primordial germ cells migrate from the wall of the yolk sac during embryonic development and enter the developing ovary
• Primary oocytes are surrounded by a single layer of flattened epithelial cells to form primordial follicles
• At puberty, primordial follicles begin to mature into primary follicles
• The primary oocyte completes its first meiotic division to give rise to a secondary oocyte and a smaller polar body

  
• Post-fertilization, the secondary oocyte undergoes secondary meiotic division to become an ovum and a second polar body
• The ovum and polar body are contained within a glycoprotein shell called the zona pellucida
• The follicle cells of the ovary develop into a corpus luteum
• The mitotic germ cells in the testis are known as spermatogonia

  
• After the last mitotic division, the male germ cell is known as the primary spermatocyte
• Series of cell divisions that leads to transformation into a multicellular body

  Cleavage
• Cleavage of the fertilized egg is initiated by the division of the nucleus
• The division of the nucleus is followed by the division of the cytoplasm
• The daughter cells are termed cleavage cells or blastomeres
• T or F: A blastomere does not increase in size before the next division

  False
• The resulting blastomeres are only have the original size after dividing
• Space between the egg and fertilization membrane

  Perivitelline space
• The starfish egg undergoes holoblastic cleavage
• The starfish embryo has radial symmetry
• The fluid-filled central cavity cells arrange themselves around in late cleavage

  Blastula
• The blastocoel develops at the 128-cell stage
• Blastomere cells are held together by cell adhesion molecules called EP-cadherin
• Label the figure:

  A) unfertilized egg

  B) zygote

  C) 2 cell stage

  D) 4 cell stage

  E) 8 cell stage

  F) 16 cell stage (morula)

  G) early blastula

  H) late blastula

  I) early gastrula

  J) late gastrula