Exam 3 Flashcards
Echinoderms are classified as chordates because their larvae possess a notochord.
False
What are the type/s of cell movement observed in sea urchins?
ingression, invagination, convergent extension
What type of cleavage is present in sea urchin embryos?
Radio holoblastic
What is the term for the free-swimming sea urchin larva?
Pluteus larva
What is the term for the initial sea urchin gut formed by invagination of cells during gastrulation?
Archenteron
Of the cells in a 16-cell sea urchin embryo, which are autonomously specified?
The large micromeres
What effect do large micromeres have on adjacent cells in a sea urchin embryo?
They induce cells above to become endomesoderm cells that invaginate during gastrulation.
Between fertilization and the first cleavage division, the cytoplasm of the frog egg rotates 30 degree away from the point of sperm entry in a process called ___________
cortical rotation
Which cells are autonomously specified and conditionally specify the fate of other cells?
Micromeres
Double-negative gated gene regulatory network specifies the veg2 macromere in a sea urchin embryo.
True
In the famous Hans Spemann and Hilde Mangold experiment, what tissue was the organizer for embryonic development in amphibians?
dorsal blastopore lip
The first cells that enter the dorsal lip of the blastopore form the truck and the tail.
False
Which protein is responsible for determining the ventral axis in the amphibian embryo?
BMP
Which group of organisms includes only anamniotes?
Fish and amphibians
Which statement best describes a frog egg prior to fertilization?
It has clearly distinct poles with much more yolk in the vegetal pole versus the animal pole.
What causes a gray crescent to appear in many frog embryos?
The outer (cortical) cytoplasm rotates relative to the internal cytoplasm.
What is the term for the slit-like structure formed by the invagination of Xenopus epithelium as mesoderm and endoderm move deeper into the embryo?
The blastopore
Which statement is accurate regarding the effects of dorsal blastopore lips on development?
Dorsal blastopore lips induce brain formation early in development and spinal cord formation later in development.
Which choice is not one of the three major axes formed in a developing amphibian?
Superior-inferior
What chemical is responsible for stimulating the development of epithelial tissue from ectoderm?
Bone morphogenetic protein
What gradient is usually responsible for the formation of a distinct anterior-posterior axis?
Wnt proteins
Which structure develops directly from Xenopus organizer cells, not from induction by these cells?
The notochord
If a sperm penetrates a Xenopus egg at the lower right of the cell, which side of the cell will become the dorsal side?
The side 180 degrees clockwise from the location of sperm penetration.
What structure is the double-headed arrow pointing to?
amnion
What tissue derivative in early human embryo forms the embryonic endoderm?
Epiblast
During _________________, cells in the early human embryo change their adhesive properties and become tightly attached to each other.
Compaction
The hatching of the embryo from the zona pellucida takes place because of
Cortical granule reaction is used for
polyspermy block
Which extraembryonic membrane is used for waste storage in amniote embryos?
The allantois
What type of cleavage is present in bird embryos?
Discoidal meroblastic cleavage
Which structure is essential for the movement of cells during gastrulation in birds and mammals but not in amphibians?
The primitive streak
What is the organizer tissue in birds?
Hensen’s node
What unique type of cleavage is common in mammals?
Rotational cleavage
How is the mammalian blastocoel formed?
The cells undergo cavitation,
What is not a unique characteristic of mammalian embryos?
having unusually rapid cell division.
What is the term for the region of the mammalian reproductive system in which fertilization occurs?
The oviduct
The regression of the primitive streak results in the elongation of the notochord.
True
The yolk sac is derived from the epiblast.
False
Arrange the right order in which the human embryo implants the uterus.
Apposition
Adhesion
Progression
Decidualization
If a two-cell embryo splits resulting in two inner cell masses and two trophoblasts it will lead to a human monozygotic twin born within
two chorions and two amnions
Alcohol, in sufficient quantity (which can be very small), is a teratogen when consumed during pregnancy. It can result in______________________________
craniofacial and brain abnormalities
