Topic 14 Word Roots
a- not, without (asexual reproduction: a type of reproduction involving only one parent that produces
genetically identical offspring)
acro- tip; -soma body (acrosome: a membrane-enclosed sac at the tip of a sperm that contains
enzymes that help the sperm penetrate an egg)
blast- bud, sprout (blastula: an embryonic stage that marks the end of cleavage during animal
development; in many species a hollow ball of cells); -coel opening (blastocoel: the fluid-filled cavity
inside a blastocyst); -cyst sac, bladder (blastocyst: a mammalian embryo [equivalent to an amphibian
blastula] made up of a hollow ball of cells that results from cleavage and that implants in the mother’s
endometrium)
coel- opening (coelom: a body cavity completely lined by mesoderm)
contra- against (contraception: the deliberate prevention of pregnancy)
corpus body; lut- yellow (corpus luteum: a small body of endocrine tissue, yellow in color, that
develops from an ovarian follicle after ovulation and secretes progesterone and estrogen during
pregnancy)
ecto- outside; -derm skin (ectoderm: the outer layer of three embryonic cell layers in a gastrula, which
forms the skin of the gastrula and gives rise to the epidermis and nervous system in the adult)
-ectomy cut out (vasectomy: the cutting of each vas deferens to prevent sperm from entering the urethra)
endo- within (endoderm: the innermost of three embryonic cell layers in a gastrula, which forms the
archenteron in the gastrula and gives rise to the innermost linings of the digestive tract and other hollow
organs in the adult; endometrium: the inner lining of the uterus in mammals, supplied with blood vessels
that provide the maternal part of the placenta and nourish the developing embryo)
epi- above, over (epididymis: a long coiled tube into which sperm pass from the testis and are stored
until they mature and are ejaculated)
extra- beyond (extraembryonic membrane: four membranes [the yolk sac, amnion, chorion,
andallantois] that form a life-support system for the developing embryo of a reptile, bird, or mammal)
fertil- fruitful (fertilization: the union of the nucleus of a sperm cell with the nucleus of an egg cell,
producing a zygote)
gameto- sex cell; -genesis producing (gametogenesis: the production of gametes within the gonads)
gastro- stomach, belly (gastrulation: the formation of a gastrula from a blastula)
hermaphrod- with both male and female organs (hermaphroditism: a condition in which an individual
has both female and male gonads and functions as both a male and female in sexual reproduction by
producing both sperm and eggs)
labi- lip; major- larger (labia majora: a pair of outer thickened folds of skin that protect the female
genital region) minor- smaller (labia minora: a pair of slender skin folds that enclose and protect the
opening to the urethra and vagina)
menstru- month (menstrual cycle: the hormonally synchronized cyclic buildup and breakdown ofthe
endometrium of some primates, including humans; menstruation: uterine bleeding resulting from
shedding of the endometrium during a menstrual cycle)
meso- middle (mesoderm: the middle layer of the three embryonic cell layers in a gastrula; gives rise
to muscles, bones, the dermis of the skin, and most other organs in the adult)
noto- the back; -chord a string (notochord: a flexible, cartilage-like, longitudinal rod located between
the digestive tract and nerve cord in chordate animals; present only in embryos in many species)
oo- egg; -genesis producing (oogenesis: the formation of egg cells [ova])
ovu- egg (ovulation: the release of an egg cell from an ovarian follicle; ovum [plural, ova]: the female
gemetes; the haploid, unfertilized egg)
sem- seed (semen: the sperm-containing fluid that is ejaculated by the male during orgasm);fercarrying (seminiferous: a coiled sperm-producing tube in a testis); vesic- sac or bladder(seminal
vesicle: a gland in males that secretes a fluid component of semen that lubricates and nourishes sperm)
spermato- sperm; -genesis producing (spermatogenesis: the formation of sperm cells)
tri- three (trimester: a three-month period)
tropho- nourish; blast- bud, sprout (trophoblast: the outer portion of a blastocyst, whose cells secrete
enzymes that enable the blastocyst to implant in the endometrium of the mother’s uterus)
-villus shaggy hair (chorionic villus: an outgrowth of the chorion, containing embryonic bloodvessels)
Vitro glass (in vitro fertilization: a technique in which a woman’s eggs are fertilized outside the body in
a test tube or glass dish)