Cell Signaling MCQs

Cell Signaling MCQs Multiple Choice Questions with Answers

1. An agent secreted by a cell that can influence the properties of another cell:
a. Receptor
b. Antigen
c. Pheromone
d. Ligand
Answer: d. Ligand

2. Hormones are signaling molecules of which system?
a. Nervous system
b. Endocrine system
c. Immune system
d. Circulatory system
Answer: b. Endocrine system

3. In human beings, UV light acts as an incoming signal to promote the synthesis of a protective pigment called:
a. Melanin
b. Bilirubin
c. Urochrome
d. Pheromone
Answer: a. Melanin

4. Which of the following transmit information both electrically and chemically?
a. Neurons
b. Nephrons
c. Dendrocytes
d. All of these
Answer: a. Neurons

5. Which of the following is not a local regulator?
a. Growth factor
b. Histamine
c. Prostaglandins
d. Oxytocin
Answer: d. Oxytocin

6. A signaling molecule that diffuses through the interstitial fluid and acts on nearby cells is called:
a. Motor neuron
b. Local regulator
c. Transporter
d. Transmitter
Answer: b. Local regulator

7. In many signaling cascades in prokaryotic and animal cells, the second messenger is?
a. cAMP
b. cATP
c. NO
d. G proteins
Answer: a. cAMP

8. Who identified cAMP as a second messenger in the 1960s?
a. Daniel Amon
b. Jean Senebier
c. Earl Sutherland
d. Cornelis van Niel
Answer: c. Earl Sutherland

9. Specialized receptors in the vertebrate eye that respond to light signals are:
a. Rhodopsin
b. Phytochrome
c. Cryptochromes
d. Melanophores
Answer: a. Rhodopsin

10. Cell surface receptors represent about…………..of all human proteins:
a. 30%
b. 50%
c. 60%
d. 80%
Answer: a. 30%

11. Which of the following ligands binds to the extracellular receptors?
a. Nitric oxide
b. Growth hormones
c. Steroid hormones
d. Thyroid hormones
Answer: b. Growth hormones

12. The largest family of human cell surface receptors is the:
a. G protein-coupled receptors
b. Ion channel-linked receptors
c. Enzyme-linked receptors
d. Receptor Tyrosine Kinase
Answer: a. G protein-coupled receptors

13. The sequence of changes in a series of different molecules that occurs during cell signaling is:

a. Nerve impulse
b. Reflex arc
c. Signal transduction pathway
d. Reflex action
Answer: c. Signal transduction pathway

14. Chemicals that take information about nerve impulse from one neuron to another neuron are called:
a. Hormones
b. Pheromones
c. Neurotransmitters
d. Transducers
Answer: c. Neurotransmitters

15. Which of the following is used for long-distance signaling in both plants and animals?
a. Hormones
b. Protein kinases
c. Transducers
d. Ligand binding proteins
Answer: a. Hormones

16. There are how many categories of cell signaling?
a. Two
b. Ten
c. Seven
d. Four
Answer: d. Four
Explanation: There are four main types of cell signaling found in multicellular organisms: paracrine, autocrine, endocrine, and signaling by direct contact.

17. Which of the following type of signaling is involved in Paracrine signaling?
a. Autostimulation of cell
b. Hormonal Communication
c. Synaptic transmission
d. Chemical signaling
Answer: d. Chemical signaling

18. Which of the following statements is true regarding cell signaling?
a. Cell signaling has four basic categories
b. is used to study the context of human diseases
c. In plants cell signaling occurs through phytohormones
d. All of these
Answer: d. All of these

19. The target cells of a lipid-soluble hormone such as cortisol, are able to respond to it because of:
a. They have membrane-bound cell surface receptors
b. Only target cells express appropriate cytosolic receptors
c. Their genome includes the appropriate transcriptional response
d. All of these
Answer: b. Only target cells express appropriate cytosolic receptors

20. Which of the following signal molecules is NOT used for extracellular signaling?
a. Cyclic AMP
b. Endocrine
c. Autocrine
d. Paracrine
Answer: a. Cyclic AMP

21. Which signal molecules does NOT interact with cell surface receptor?
a. Testosterone
b. Glucagon
c. Gastrin
d. Insulin
Answer: a. Testosterone

22. Which of the following guanine nucleotide-binding proteins (G-protein) takes part in the regulation of vision?

a. Gs family
b. Gq family
c. Gi family
d. Golf
Answer: c. Gi family

23. Which of the following signaling pathway is followed by the T lymphocyte’s response to antigenic stimulation?
a. Juxtacrine signaling
b. Autocrine signaling
c. Paracrine signaling
d. Endocrine signaling
Answer: b. Autocrine signaling

24. What molecules can directly convert extracellular signals into intracellular signals?
a. transmembrane proteins
b. Cell-surface receptors
c. GPCRs
d. All of these
Answer: d. All of these

25. Choose the correct statement about the paracrine messenger molecules:
a. The messenger molecules are unstable
b. The messenger molecules are stable
c. The messenger molecules are short
d. The messenger molecules are large
Answer: a. The messenger molecules are unstable

26. Which of the following messenger molecules are derived from the fatty acid arachidonic acid?
a. Eicosanoids
b. Terpenoids
c. Corticoids
d. Steroids
Answer: a. Eicosanoids

27. Which of the following type of signaling the cell that expresses messenger molecules also produces receptors?
a. Paracrine
b. Heterocrine
c. Endocrine
d. Autocrine
Answer: d. Autocrine

28. How many transmembrane helices are present in the GPCRs (G-protein coupled receptors)?
a. One
b. Fiver
c. Four
d. Seven
Answer: d. Seven

29. All steroid hormones are derived from:
a. Chemicals
b. Hormones
c. Cholesterol
d. Carbohydrates
Answer: c. Cholesterol

30. Which of the following signaling molecules are used by simple nerve reflexes?
a. Proteases
b. G proteins
c. Neurotransmitters
d. Nitric oxides
Answer: c. Neurotransmitters