Vocabulary 2.4
Across
- 1. reproductive cell of plant or animal
- 8. hollow sphere cells produced during embryo development by repeated cleavage of a fertilized egg.
- 9. the outermost fetal membrane around the embryo in mammals, birds and reptiles’
- 10. a small membranous structure outside the embryo with various functions during embryonic development
- 11. a series of mitotic divisions where the enormous volume of egg cytoplasm is divided into nucleated cells.
- 12. process in which an embryo transforms from one layer of epithelial cells, a blastula, and reorganizes into multiple layers.
- 15. sperm and egg fuse to form diploid zygote
- 16. a cluster of dividing cells made by a fertilized egg
- 17. cells forming the outer layer of a blastocyst, which provides nutrients to the embryo, and develops into a large part of the placenta
- 19. a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes
- 20. the outermost of the three primary germ layers of an embryo
- 21. process in which the female gametes, or ova are created
Down
- 2. consist of the chorion , amnion, yolk sac, and allantois
- 3. fertilized egg cells that result from the unions of a female gamete with a male gamete
- 4. process of producing sperm cells
- 5. an organ that connects the developing fetus to the uterine wall
- 6. an extra-embryonic membrane of reptiles, birds, and mammals arising as a pouch, or sac, from the hindgut
- 7. the innermost of the three basic layers of an embryo that forms the epithelium of the digestive tract
- 12. early multicellular embryo with two or more germinal layers of cells
- 13. a membrane that closely covers the human and various other embryos when first formed
- 14. the middle of the three primary germ layers of an embryo
- 18. the production of gametes from haploid precursor cells