The single cell formed from separate sperm and egg cells at conception
The cell released monthly from a woman’s ovaries, which, if fertilized, forms the basis for the developing organism.
The tube that is between the ovary and the uterus and where conception usually occurs
The female organ in which the embryo/fetus develops
The cells produced in a man’s testes that may fertilize an ovum following intercourse
The structures, arrayed in 23 pairs, within each cell in the body that contain genetic information.
The chromosomes are composed of long strings of molecules of a chemical
A uniquely coded segment of DNA
in a chromosome that affects one or more
specific body processes or developments.
The pattern of characteristics and developmental sequences mapped in the genes of any specific individual, which will be modified by individual experience into the phenotype.
The set of actual observed characteristics of the individual; a product of three things: the genotype, environmental influences from the time of conception onward, and the interaction between the two.
The first stage of prenatal
development, beginning at conception and
ending at implantation of the zygote in the
uterus (approximately the first 2 weeks).
Name for the mass of cells from roughly 4 to 10 days after fertilization.
The name given to the developing organism during the period of prenatal development between about 2 weeks and 8 weeks after conception, beginning with implantation of the blastocyst in the uterine wall.
The second stage of prenatal development, from week 2 through week 8, when the embryo’s organs form.
The sac, or bag, filled with liquid
in which the embryo/fetus floats during
The outer layer of cells of the
blastocyst during prenatal development, from which both the placenta and the umbilical cord are formed.
An organ that develops between the fetus and the wall of the uterus during gestation
The cord connecting the
embryo/fetus to the placenta, containing two arteries and one vein.
The name given to the developing organism from about 8 weeks after conception until birth.
the third stage of prenatal development, from week 8 to birth, when growth and organ refinement take place
The fetus’s capacity for survival outside the womb.
The specialized cells of the nervous system that are responsible for transmission and reception of nerve impulses
The part of the cell that contains the nucleus and in which all the cell’s vital functions are carried out
Tiny spaces across which neural impulses flow from one neuron to the next.
Tail-like extensions that can grow to be several feet in length.
Tentacle-like branches that extend out from the cell body.
The ‘glue’ that holds neurons together to give form to the structures of the nervous system.
Substances such as viruses and drugs or events that can cause birth defects.
A genetic anomaly in which every cell contains three copies of chromosome 21 rather than two.
A pattern of abnormalities, including mental retardation and minor physical anomalies, often found in children born to alcoholic mothers.
Term describing the genetic
pattern when the two genes in the pair at
any given genetic locus both carry the same instructions.
Term describing the genetic pattern when the two genes in the pair at any given genetic locus carry different instructions,
The pattern of genetic
transmission in which a single dominant
gene influences a person’s phenotype,
but an individual must have two recessive
genes to express a recessive trait.