So-called "combination" birth control pills function in contraception by
inhibiting the release of GnRH, FSH, and LH.
For which of the following is the number the same in spermatogenesis and oogenesis?
meiotic divisions required to produce each gamete
A high rate of metabolic activity is maintained in the pregnant uterus by
progesterone.
Labor contractions can be increased by the medical use of a synthetic drug that mimics the action of
oxytocin.
During human heterosexual (mutual) excitement, vasocongestion
occurs in the clitoris, vagina, and penis.
The hypothalamic hormone that stimulates hormone secretion by the anterior pituitary gland is
gonadotropin-releasing hormone (GnRH)
A vasectomy
prevents sperm from exiting the male urethra.
In vertebrate animals, spermatogenesis and oogenesis differ in that
cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis.
Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because
asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring.
The major excitatory neurotransmitter of the human brain is
glutamate.
The point of connection between two communicating neurons is called
the synapse.
Our understanding of mental illness has been most advanced by discoveries involving
the chemicals involved in brain communications.
In all vertebrate animals, development requires
an aqueous environment.
A reproductive difference between sea urchins and humans is
the sea urchin egg completes meiosis prior to fertilization, but meiosis in humans is completed after fertilization.
The membrane potential that exactly offsets an ion's concentration gradient is called the
equilibrium potential.
At the moment of sperm penetration, human eggs
are still surrounded by follicular cells.
The endogenous nature of biological rhythms is based on the observations that animals isolated from light and dark cues
continue to have cycles of approximately 24 hours' duration; some more rapid, some slower.
The somatic nervous system can alter the activities of its targets, the skeletal muscle fibers, because
its signals bind to receptor proteins on the muscles.
The unconscious control of respiration and circulation are associated with the
medulla oblongata.
In a developing frog embryo, most of the yolk is
located near the vegetal pole
The vegetal pole of the zygote differs from the animal pole in that
the vegetal pole has a higher concentration of yolk.
The cerebral cortex plays a major role in all of the following except
circadian rhythm
After the depolarization phase of an action potential, the resting potential is restored by
the opening of voltage-gated potassium channels and the closing of sodium channels.
The suprachiasmatic nuclei are found in the
hypothalamus
Meroblastic cleavage occurs in
birds, but not sea urchins or humans.
The earliest developmental stage among these choices is
morula
The archenteron of the developing frog eventually develops into the
digestive tract
The central nervous system is lacking in animals that have
radial symmetry
Among these choices, the largest cell involved in frog reproduction is
the ovum
Two contraceptive methods that are generally irreversible and which block the gametes from moving to a site where fertilization can occur are
vasectomy and tubal ligation
For lactation to take place, the synthesis of breast milk and its release from the mammary gland, respectively, are caused by
prolactin and oxytocin
Sexual reproduction patterns include the example of
hermaphroditism
Which of the following is not properly paired?
seminiferous tubule & cervix
Sexual reproduction
can produce diverse phenotypes that may enhance survival of a population in a changing environment.
A function-disrupting mutation in the progesterone receptor gene would likely result in
the inability of the uterus to support pregnancy.
A high rate of metabolic activity is maintained in the pregnant uterus by
progesterone
Evidence that parthenogenic whiptail lizards are derived from sexually reproducing ancestors includes
the requirement for male-like behaviors in some females before their partners will ovulate.
Regeneration, the regrowth of lost body parts, normally follows
fragmentation
Among these contraception methods, the highest risk of accidental pregnancy accompanies
the practice of coitus interruptus.
A human blastomere is
an embryonic cell that is much smaller than the ovum.
Uterine implantation due to enzymatic digestion of the endometrium is initiated by the
Trophoblast
Two fundamental concepts about the ion channels of a "resting" neuron are that the channels
open and close depending on stimuli, and are specific as to which ion can traverse them.
An amino acid neurotransmitter that operates at inhibitory synapses in the brain is
gamma-aminobutyric (GABA)
The arrangement of organs and tissues in their characteristic places in 3-D space defines
pattern formation
The archenteron of the developing frog eventually develops into the
digestive tract
Wernicke's and Broca's regions of the brain affect
speech
Ionotropic receptors are found at synapses operated via
ligand-gated ion channels
Wakefulness is regulated by the reticular formation, which is present in the
brainstem
Choose the correct match of glial cell type and function
astrocytes: metabolize neurotransmitters and modulate synaptic effectiveness
Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?
Voltage-gated calcium channels in the membrane open
Hormones that are secreted by the posterior pituitary gland are made in the
hypothalamus.
Neurotransmitters affect postsynaptic cells by
All of these options are correct
altering the permeability of the cells.
affecting ion-channel proteins.
initiating signal transduction pathways in the cells.
causing molecular changes in the cells.
Which of the following structures are correctly paired?
hindbrain and cerebellum
The following steps refer to various stages in transmission at a chemical synapse. Which sequence of events is correct?
An action potential depolarizes the membrane of the axon terminal → Calcium ions rush into neuron’s cytoplasm → The synaptic vesicles release neurotransmitter into the synaptic cleft → Neurotransmitter binds with receptors associated with the postsynaptic membrane → The ligand-gated ion channels open
An organism that lacks integration centers
will not be able to interpret stimuli
The "undershoot" phase of after-hyperpolarization is due to
sustained opening of voltage-gated potassium channels.
What structural adaptation in chickens allows them to lay their eggs in arid environments rather than in water?
extraembryonic membranes
A primitive streak forms during the early embryonic development of
humans and birds, but not frogs
The activity of acetylcholine in a synapse is terminated by
its degradation by a hydrolytic enzyme on the postsynaptic membrane
Saltatory conduction is a term applied to
jumping from one node of Ranvier to the next in a myelinated neuron
If gastrulation was blocked by an environmental toxin, then
embryonic germ layers would not form.
In mammalian eggs, the receptors for sperm are found in the
zona pellucida.
The release of acetylcholine from the terminal of a motor neuron is most directly linked to
the entry of calcium into the axon terminal