animal biology - 2
Terms in this set (59)
the joining of haploid gametes to form a diploid zygote
the cavity inside the blastula is called the
the formation of the fertilization envelope and the slow block to polyspermy are dependent on
the entrance of calcium ions into the egg
the outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is
ectoderm, mesoderm, endoderm
during cleavage, the size of the embryo increases with each doubling of the number of cells.
TRUE or FALSE
an embryo has different cell types because cells express different genes depending on.....
their location, the signalling molecules to which they are exposed, cytoplasmic determinants, stage development
in a newly fertilized egg, the vitelline later
hardens to form a protective cover
if a mutation occurred in a sea urchin sperm that prevented the acrosomal reaction from occurring, what would happen?
sperm would be unable to penetrate the jelly coat of an egg
a cell that would normally develop into a muscle cell is moved to a different location within the embryo where cells normally develop into bone cells. The relocated cell still develops into a muscle cell. Which mechanism is responsible for determining the cells fate?
An organism or cell having only one complete set of chromosomes.
2 sets of chromosomes
A vesicle at the tip of a sperm cell that helps the sperm penetrate the egg
a structure formed by the extracellular matrix of the egg
Forms sperm resistant membrane when fused with plasma membrane of egg
binds to receptors in the egg in a lock-and-key fashion
The protective layer formed when the vitelline layer of an egg is pushed away from the plasma membrane and hardened after fertilization by molecules exocytosed during the cortical reaction.
space between the plasma membrane and the vitelline layer
an increase in egg metabolism and protein synthesis that begins within minutes after fertilization
Smaller cells produced by cleavage during mitotic cell division
hollow ball of cells
the fluid-filled cavity of a blastula
The point at the end of an egg in the hemisphere where the least yolk is concentrated; opposite of vegetal pole.
The portion of the egg where most yolk is concentrated; opposite of animal pole.
differential gene expression
the expression of different genes by cells with the same genome
A maternal substance, such as a protein or RNA, placed into an egg that influences the course of early development by regulating the expression of genes that affect the developmental fate of cells.
cause cells to change shape, migrate, or even destroy other cells
produces two daughter cells with different cellular fates
sister cells become different as a result of influences acting on them after their birth
the development of the form of an organism and its structures
In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula.
formation of organs
development of the nervous system
one of the three cell layers present in an embryo
outermost germ layer; produces sense organs, nerves, and outer layer of skin
middle germ layer; develops into muscles, and much of the circulatory, reproductive, and excretory systems
innermost germ layer; develops into the linings of the digestive tract and much of the respiratory system
The endoderm-lined cavity, formed during gastrulation, that develops into the digestive tract of an animal.
flat group of cells present in prenatal development that becomes the brain and spinal cord
a groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord
A process in which the cells of a tissue layer rearrange themselves, so that the sheet of cells becomes narrower (converges) and longer (extends).
programmed cell death
what joins to form a diploid zygote
through what process are haploid gametes formed
what are the haploid gametes in sea urchin reproduction
egg and sperm
what does the jelly coat do
releases molecules that attract sperm of the same species
what triggers the acrosomal reaction?
contact with the jelly coat
what are inside the acrosome
what do the hydrolytic enzymes inside of the acrosome do
digest jelly coat so sperm can enter
what blocks polyspermy
plasma membrane fuses shut
what part of the cell is most negative
how do the sperm binding receptors get broken?
cortical granules release contents which hardens the vitelline layer and breaks sperm binding receptors
why is polyspermy prevented
to ensure the zygote has the correct balance of maternal and paternal chromosomes
what does cleavage do
converts unicellular zygote to multicellular embryo
what phases are skipped in rapid cell division
G1 and G2
cells express different genes depending on
location and stage of development
what two mechanisms ensure a cell knows what genes to express at any given time?
cytoplasmic determinants and inductive signalling
the animal pole is the future
can the three different germ layers express different genes ?
apoptosis shapes -