development connect Flashcards
the placenta secretes large amounts of
estradiol
a high concentration of estradiol stimulates the production of _____ receptors in the _____
- oxytocin
- uterus
as the head of the fetus pushes against the, _____, stretch-sensitive sensory neurons send messages to the mother’s hypothalamus
cervix
the _____ stimulates the secretion of oxytocin from the posterior ______ gland
- hypothalamus
- pituitary
uterine contractions are stimulated by ____ and ______
- oxytocin
- prostaglandins
stronger uterine contractions lead to a _____ feedback loop
positive
in mammals, gestation is defined physiologically as the time from ____ to birth
implantation
testosterone production is subject to negative feedback, but the process of birth is subject to positive feedback. why is this appropriate?
testosterone must be maintained at homeostatic levels, whereas birth must go to completion once started
an unusual red sponge is discovered near a deep-sea vent. you want to determine if this is a new species of sponge, so you separate the cells for further study. a new lab assistant accidentally adds cells from a blue sponge to your preparation while you are at lunch. when you return, you find that the sponge cells have reaggregated into a multicellular organism. what do you see if the red and blue sponges are the same species?
one sponge with blue and red randomly distributed
a cell is considered to be _____ when it is committed to becoming a particular cell type, such as an intestinal cell or a muscle cell. a cell is considered to be ____ when its morphology and function have changed, usually permanently, into a highly specialized cell type
- determined
- differentiated
four possible outcomes when an embryonic cell responds to positional information
- cell division
- cell migration
- cell differentiation
- cell death (apoptosis)
the outcome of cleavage during embryonic development is the production of a
blastula
survivin is an apoptosis inhibitor in humans. if the survivin gene is mutated so that it produces too much of the Survivin protein, which of the following would be the most likely effect on limb formation?
webbing between digits would not be removed
what are induced pluripotent stem cells
adult stem cells that have been made in the laboratory
you are given a rare opportunity to observe human prenatal development in utero via a special camera implanted in the mother’s uterus. during the first viewing session, you observe that the baby has the fundamental features of its nervous system, brain, heart, liver, and circulatory system, but that its lungs lack alveoli (sacs needed for oxygen/ CO2 exchange). it is about 6 inches long. what would be the proper term for the baby? what stage of pregnancy is the mother in?
fetus; second trimester
the central nervous system first forms during
neurulation
in your lab course, your instructor gave you a sample of testis and an ovary to observe under the microscope, but you accidentally mixed up the labels. what characteristic will allow you to identify the samples?
a large number of cells arrested in meiosis 1 will identify the ovary
which of the following statements about stem cells is NOT accurate?
stem cells are only found in embryos
which of the following are at high risk from week 3 through week 16 of a pregnancy?
central nervous system
