Biol Ch. 3 - Embryogenesis and Development Flashcards
What is the widest part of the fallopian tube?
Ampulla
What is the release of calcium ions following sperm penetration? These calcium ions depolarize the membrane of the ovum, which serves two purposes: depolarization prevents fertilization of the ovum by multiple sperm cells, and the increased calcium concentration increases the metabolic rate of the newly formed diploid zygote.
Cortical reaction
What form from fertilization of two different eggs released during one ovulatory cycle by two different sperm?
Dizygotic (fraternal) twins
What form when a single zygote splits into two? Because the genetic material is identical, the genomes of the offspring will be too. If division is incomplete, conjoined twins may result, where the two offspring are physically attached.
Monozygotic (identical) twins
What results in cells that can still develop into complete organisms?
Indeterminate cleavage
What results in cells with fates that are, as the term implies, already determined? In other words, these cells are committed to differentiating into a certain type of cell.
Determinate cleavage
What is a solid mass of cells?
Morula
What is the hollow ball of cells that forms after morula undergoes blastulation? Implantation occurs during this stage.
Blastula
What is fluid-filled inner cavity of blastula?
Blastocoel
What is the mammalian blastula?
Blastocyst
What surround the blastocoel and give rise to the chorion and later the placenta?
Trophoblast cells
What protrudes into the blastocoel and gives rise to the organism itself?
Inner cell mass
What is an extraembryonic membrane that develops into the placenta?
Chorion
What consists of two arteries and one vein encased in a gelatinous substance?
Umbilical cord
What is the site of early blood cell development?
Yolk sac
What involved in early fluid exchange between the embryo and the yolk sac?
Allantois
What surrounds allantois? It is a thin, tough membrane filled with amniotic fluid.
Amnion
What generates three distinct cell layers?
Gastrulation
What is the invagination into the blastocoel?
Archenteron
What is the opening of the archenteron?
Blastopore
What are organisms (humans included) where blastopore develops into anus?
Deuterostomes
What are organisms where blastopore develops into mouth?
Protostomes
What is the outermost layer which gives rise to the integument, including the epidermis, hair, nails, and the epithelia of the nose, mouth, and lower anal canal? The lens of the eye, nervous system (including adrenal medulla), and inner ear are also derived from it.
Ectoderm
What is the middle layer which develops into several different systems including musculoskeletal, circulatory, and most of the excretory systems? It also gives rise to the gonads as well as the muscular and connective tissue layers of the digestive and respiratory systems and the adrenal cortex.
Mesoderm
