primitive streak
The result of polyspermy in humans is ________.
A) multiple births
B) a nonfunctional zygote
C) interruption of meiosis
D) mitotic insufficiency
a nonfunctional zygote
It is impossible for sperm to be functional (able to fertilize the egg) until after ________.
A) the tail disappears
B) they become spermatids
C) they undergo capacitation
D) they have been stored in the uterus for several days
oxytocin
corpus luteum
The placenta, a vitally important metabolic organ, is made up of a contribution from mother and fetus. Which portion is from the fetus?
A) chorion
B) umbilicus
C) yolk sac
D) amnion
chorion
Relaxin is a hormone produced by the placenta and ovaries. The function of this hormone is to ________.
A) block the pain of childbirth
B) ensure the implantation of the blastula
C) relax the pubic symphysis
D) prevent morning sickness
Proteases and acrosin are enzymes. How do they function in reproduction?
A) They neutralize the mucous secretions of the uterine mucosa.
B) They direct the sperm to the egg through chemical messengers.
C) They act to break down the protective barriers aro
The formation of endodermal and ectodermal germ layers occurs at ________.
A) fertilization
B) cleavage
C) gastrulation
D) blastula formation
gastrulation
Which hormone maintains the viability of the corpus luteum?
A) estrogen
B) progesterone
C) human chorionic gonadotropin
D) human placental lactogen
human chorionic gonadotropin
The correct sequence of preembryonic structures is ________.
A) zygote, blastocyst, morula
B) zygote, morula, blastocyst
C) blastocyst, morula, zygote
D) morula, zygote, blastocyst
temperature
oxytocin
Muscle tissue is formed by the ________.
A) mesoderm
B) ectoderm
C) endoderm
D) epiderm
mesoderm
Neural tissue is formed by the ________.
A) epiderm
B) endoderm
C) mesoderm
D) ectoderm
ectoderm
The trophoblast is mostly responsible for forming the ________.
A) allantois
B) archenteron
C) placental tissue
D) lining of the endometrium
Sperm move to the uterine tube through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement?
A) hormonal attraction to the ova
B) reverse peristalsis of the uterus and uterine tubes
C) the cilia on the
At which stage of labor is the "afterbirth" expelled?
A) dystocia
B) expulsion
C) placental
D) full dilation
placental
inhibin
During which stage of labor is the fetus delivered?
A) dilation stage
B) expulsion stage
C) placental stage
D) gastrula stage
expulsion stage
Which of the following is true in reference to what may pass through the placental barriers?
A) nutrients and respiratory gases only
B) hormones, blood cells, and nutrients
C) nutrients, respiratory gases, wastes, and alcohol
D) respiratory gases, hormone
aspirin
Select the correct statement about the special fetal blood vessels.
A) The distal parts of the umbilical arteries form the superior vesical arteries.
B) The fossa ovalis becomes the foramen ovale.
C) The umbilical vein becomes the ligamentum teres.
D) The