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