14 Flashcards
(22 cards)
Term
Definition
Asexual reproduction
Gives rise to offspring genetically identical to the parent.
Sexual reproduction
Involves mixing genomes from two individuals to produce genetically distinct offspring.
Gametes
Specialized haploid cells (egg and sperm) that fuse to form a diploid zygote.
Meiosis
Process where diploid cells produce haploid gametes with recombined chromosomes.
Zygote
Diploid cell formed by the fusion of egg and sperm, develops into a new individual.
Fertilization
Fusion of egg and sperm, resulting in a zygote.
Zona pellucida
Glycoprotein layer protecting the egg, targeted during acrosomal reaction.
Acrosomal reaction
Biochemical event where sperm enzymes digest zona pellucida to allow fusion.
Cleavage
Rapid cell divisions of the zygote without growth, forming the blastula.
Blastula
Spherical layer of cells surrounding a fluid-filled cavity after cleavage.
Blastocyst
Mammalian blastula with inner cell mass and outer trophoblast.
Blastomere
Individual cell resulting from cleavage.
Holoblastic cleavage
Total cleavage in eggs with little yolk (e.g., mammals).
Meroblastic cleavage
Partial cleavage in yolk-rich eggs (e.g., birds).
Trophoblast
Outer layer of blastocyst that forms the placenta.
Embryoblast
Inner cell mass of the blastocyst that forms the embryo.
Morula
Solid ball of blastomeres resulting from early cleavage.
Gastrulation
Formation of three germ layers from blastula.
Ectoderm
Forms skin and nervous system.
Mesoderm
Forms muscles, circulatory system, and reproductive organs.
Endoderm
Forms digestive and respiratory systems and associated organs.
