answer

watching

views

25 Mar 2018

Which pituitary cell is primarily under inhibitory control from the hypothalamus?

A) gonadotrope

B) lactotrope

C) thyrotrope

D) corticotrppe

Thyroid hormone receptors

A) are frequently dimerized with retinoid X receptor

B) complex with chaperone proteins when no hormone is bound

C) have higher affinity for T4 than for T3

D) are coupled with Ga-s proteins

E) A and B are correct

answer

watching

views

For unlimited access to Homework Help, a Homework+ subscription is required.

You have 0 free answers left.
Get unlimited access to 3.8 million step-by-step answers.

Get unlimited access

Already have an account? Log in

Nelly StrackeLv2

26 Mar 2018

Unlock all answers

Get 1 free homework help answer.

Already have an account? Log in

Related questions

33 Different glycoproteins can have a diverse array of oligosaccharides. Which of the statements below for making glycoproteins on plasma membrane is true?

(a) Extensive modification of oligosaccharides occurs in the extracellular space.

(b) Initial oligosaccharide chains are made by addition of one sugar at a time onto the protein in the ER lumen.

(c) Each layer of Golgi membrane structures contains identical modification enzymes for modifying sugar chain on proteins.

(d) ER lipids can be modified by sugar chain, which can be used for sugar chain modification of the proteins.

34 In a multicellular organism, when a signal needs to be sent to most cells the signal most suited for this is a ___________.

(a) neurotransmitter.

(b) hormone.

(d) plasma membrane anchored ligands.

35 Typically, members of the steroid hormone receptor family __________________.

(a) are cell-surface receptors.

(b) do not undergo conformational changes by binding to their ligands.

(d) interact with signal molecules that diffuse through the plasma membrane

36 Which of the following statements about what happens when a G-protein-coupled receptor activates a hetero trimeric G protein is true?

(a) The Î² subunit exchanges its bound GDP for GTP.

(b) The GDP bound to the Î± subunit is phosphorylated to form bound GTP.

(d) It activates the Î± subunit and inactivates the Î²Î³ complex

37 Which of the following statements about signal transduction is false

(a) Ca2+ concentration in cytosol will increase when PLC (Phospholipase C) is activated by signal.

(b) Cyclic GMP is made in smooth muscle cells when they received NO signal.

(d) Ligand binding to RTK activates its enzyme activity then the activated RTK phosphorylates tyrosine residues on itself.

greywoodchuck816

Tetraethylammonium (TEA) is a drug that blocks voltage-gated potassium channels. What effect would this have on an action potential?

(a)Prevent the rising phase

(b)Prevent the cell from reaching the threshold to trigger an action potential

(c)Prevent or prolong the falling phase

(d)None of the above

The hyperpolarization phase of the action potential is due to:

(a)The opening of voltage-gated Cl- channels

(b)Prolonged opening of voltage gated K+ channels

(c)The closure of resting Na+ channels

(d)Rapid inactivation of voltage-gated K+ channels

The period when it is difficult to initiate another action potential for several milliseconds due to voltage-gated sodium channel inactivation is referred to as the:

(a)Relative refractory period

(b)Absolute refractory period

(c)Resting period

(d)Hyperpolarization period

In the human central nervous system, Gap junctions are found:

(a)Only between neurons

(b)Only between astrocytes

(c)In both neurons and astrocytes

(d)In all cells

Small molecule transmitters such as acetylcholine are synthesized in:

(a)The nerve terminal

B) The cell body and transported to the nerve terminal

C) Synaptic vesicles

D) Endoplasmic reticulum

Prior to Otto Loewiâs classical experiment, which of the following was not known:

(a)stimulation of the vagus nerve slows the heart

(b)extracts of frog heart, made following vagal nerve stimulation, slow the heart

(c)some acetylcholine effects are similar to those produced by muscarine

(d)vagal nerve stimulation releases a substance which slows the heart

Which of the following is most important in determining if neurotransmission is excitatory or inhibitory?

(a)The structure of the synapse

(b)The neurotransmitter released by the presynaptic neuron

(c)The neurotransmitter receptor

(d)The strength of the stimulus

Benzodiazepines such as Valium allosterically regulate GABA receptors by:

(a)Binding at receptor sites other than the transmitter binding site

(b)Binding at the transmitter (GABA) binding site on the receptor

(c)Blocking the action of the endogenous transmitter

(d)Mimicking the action of the endogenous transmitter

GABA-A receptors are ligand-gated Cl- channels. The equilibrium potential of Cl- is -65 mV. At the neuronal resting membrane potential of -65 mV, GABA binding to the GABA-A receptor would result in the opening the Cl- channel, resulting in:

(a)no net flow of Cl- ions

(b)Cl- inflow and hyperpolarization

(c)Cl- outflow and depolarization

(d)Cl- outflow and hyperpolarization

At the mammalian neuromuscular junction, the released neurotransmitter acts on:

(a)muscarinic receptors

(b)nicotinic receptors

(c)adrenergic receptors

(d)Beta receptors

Neurotransmitters are packaged into synaptic vesicles by:

(a)endocytosis following transmitter release

(b)presynaptic membrane transporters

(c)vesicular transporters

(d)all of the above

. Which of the following are NOT types of ion channels?

Voltage-gated

(a)Ligand-gated

(b)G protein coupled receptor (GPCR)-gated

(c)Leak channels

(d)NONE of the above

NMDA receptors are unique in that their ion channel is:

(a)Ligand-gated

(b)Voltage-gated

(c)Ligand- and voltage-gated ion channels

(d)GPCR-gated

. Which of the following is INCORRECT regarding Catecholamine neurotransmitters

(a)Includes Dopamine, Norepinerphrine, and Epinephrine

(b)Contain a Catechol Ring

(c)Synthesized from Tryptophan

(d)Are produced by neurons whose cell bodies are located in the upper brainstem

The largest and most diverse group of receptors in eukaryotes is:

(a)Ligand gated receptors

(b)Glutamate receptors

(c)G-Protein coupled receptors

(d)Allosteric receptors

The most abundant G-protein coupled receptor in the brain is:

(a)Glutamate receptors

(b)Acetylcholine receptors

(c)Cannabinoid receptors

(d)Dopamine receptors

Which of the following drugs DOES NOT block voltage-gated Na+ channels

(a)Lidocaine

(b)Riluzole

(c)Reserpine

(d)Tetrodotoxin

Sarin, a nerve gas, exerts its toxicity by:

(a)blocking nicotinic receptors

(b)inhibiting choline acetyltransferase

(c)inhibiting acetylcholinesterase

(d)inhibiting voltage-gated Na+ channels

Botulinum Toxin (BoTox) interferes with transmitter release by:

(a)cleaving protein(s) involved in transmitter release

(b)blocking voltage-gated Ca2+ channels

(c)blocking voltage-gated Na+ channels

(d)blocking voltage-gated K+ channels

Atropine is:

(a)An agonist of the acetylcholine ionotropic receptor

(b)An antagonist of the acetylcholine ionotropic receptor

(c)An agonist of the acetylcholine metabotropic receptor

(d)An antagonist of the acetylcholine metabotropic receptor

1. When does differentiation begin in fruit fly (insects)?

a. Prior to fertilization

b. Just after fertilization, but before any cell divisions takeplace

c. Just after the first cell division

d. At the blastula stage

e. At the globular embryo stage

2. When does differentiation begin in frog (vertebrates)?

a. Prior to fertilization

b. Just after fertilization, but before any cell divisions takeplace

c. Just after the first cell division

d. At the blastula stage

e. At the globular embryo stage

3. When does differentiation begin in flowering plants?

a. Prior to fertilization

b. Just after fertilization, but before any cell divisions takeplace

c. Just after the first cell division

d. At the blastula stage

e. At the globular embryo stage

4. Which axis develops first in animals, anterior-posterior(A-P) or dorsal-ventral (D-V)?

a. A-P

b. D-V

c. They develop at the same time.

d. They are controlled by the same transcription factors at thesame time.

5. Which axis develops first in plants, anterior-posterior ordorsal-ventral?

a. A-P

b. D-V

c. They develop at the same time.

d. Plants only develop A-P, and with respect to gravity andlight.

6. Focusing in on A-P development in Drosophila, maternaltranscription factors produce

proteins that control axis development in what order?

a. bicoid and nanos proteins; caudal and hunchback proteins; gapand pair-rule

proteins

b. caudal and hunchback proteins; bicoid and nanos proteins; gapand pair-rule

proteins

c. gap and pair-rule proteins; bicoid and nanos proteins; caudaland hunchback

proteins

d. gap and pair-rule proteins; caudal and hunchback proteins;bicoid and nanos

proteins

7. What ultimately controls pattern formation in Drosophila?

a. Morphogen gradients and signaling molecules under maternalcontrol

b. Morphogen gradients and signaling molecules under embryoniccontrol

c. De-repressors and signaling molecules under maternalcontrol

d. De-repressors and signaling molecules under embryoniccontrol

PLANT STRUCTURE, CELLS, CELL WALLS, PLASMODESMATA

8. Which of the following cannot be found in leaves?

a. Xylem

b. Phloem

c. Mesophyll

d. Parenchyma

e. Apical meristem

9. What are intercalary meristems?

a. Meristems that develop between internodes in some plants

b. Meristems that develop primary meristematic tissues

c. Meristems that are responsible for secondary growth in woodyplants

d. Root meristems

10. Roots, shoots, and leaves all contain three basic tissuesystems. What are they?

a. Ground, structural, conductive

b. Ground, vascular, dermal

c. Vascular, dermal, structural

d. Conductive, transmissive, supportive

11. All growth in plants is due to

a. Cell division in the three basic tissue systems andsubsequent cell elongation

b. Cell division at meristems and subsequent cell elongation

c. Cell division as needed throughout the plant body, followedby cell elongation

d. Hormone-induced cell division throughout the plant body

12. Which plant cells are dead at maturity, although stillproviding some useful function?

a. Dermal

b. Ground

c. Xylem

d. Phloem

e. Lateral meristems

13. Which meristems are responsible for lateral growth (increasein girth)?

a. Apical meristem

b. Root meristem

c. Vascular and bark cambium

d. Intercalary meristem

14. Where are most guard cells generally located in vascularplants?

a. Stem dermal tissue

b. Root dermal tissue

c. Petiole dermal tissue

d. Undersides of leaves

e. Uppersides of leaves

15. How can you distinguish guard cells from non-guardcells?

a. They contain mitochondria

b. They contain chloroplasts

c. They do not have plasmodesmata

d. They have plasmodesmata

e. B and C

PINs, IAA, ACID GROWTH

16. What are PINs?

a. Plasma membrane transport inhibitors

b. Auxin efflux transporters for active transport across plasmamembranes

c. Growth regulators

d. Hormones

e. Membrane transport proteins for embryogenesis

17. What is IAA?

a. Cytokinen

b. Gibberellic acid

c. Florigen

d. Auxin

e. Abscissic acid

18. Which hormone can trigger cell wall expansion?

a. Cytokinen

b. Gibberellic acid

c. Florigen

d. Auxin

e. Abscissic acid

19. Which ion is used by plants to decrease pH and activateenzymes that break cress-bridges

between cellulose fibers for cell wall expansion?

a. Na

b. K

c. Cl

d. H

e. Mg

20. Where do the ions come from to cause acidification of thecell wall?

a. Apoplast

b. Cytoplasm

c. Chloroplasts

d. Mitochondria

e. Vacuole

PLANT EMBRYOGENESIS, SHOOT APICAL MERISTEM (SAM), ROOT APICALMERISTEM

(RAM)

21. The first cell division in a plant zygote isasymmetrical.

a. True

b. False

22. At what stage of embryogenesis do PIN proteins firstinfluence orientation of the root-shoot

axis?

a. First cell division

b. Second cell division

c. 8-cell stage

d. Globular stage

e. Heart-shaped stage

23. Which hormone most strongly affects cell division inembryos?

a. IAA

b. GA

c. Ethylene

d. AA

e. CK

24. How do the major tissue systems in plants become establishedin developing embryo?

a. Anticlinal cell divisions

b. Periclinal cell divisions

c. All of the above

d. None of the above

STEM/ROOT PRIMARY, SECONDARY GROWTH

25. Fifteen years ago, your parent hung a swing from the lowerbranch of a tree in your yard. It is at the exact same height as itwas then. Why isn

ceriseshark886

Weekly leaderboard

Home

Homework Help 3,900,000

Biology 460,000

Unlock all answers

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Concepts of Biology

Biology

Essentials of Biology

Related questions

Related Documents

BIOS1167 Lecture Notes - Lecture 7: Thyroid, Natriuretic Peptide, Pancreatic Islets

EEOB 2520 Quiz: Exam 7 notes

Weekly leaderboard