1. What is the primary function of intercellular junctions?
A) Providing structural support
B) Facilitating cell communication
C) Synthesizing proteins
D) Storing genetic material
Answer: B) Facilitating cell communication
2. Plasmodesmata are found in which type of cells?
A) Animal cells
B) Plant cells
C) Bacterial cells
D) Fungal cells
Answer: B) Plant cells
3. Gap junctions are primarily found in which organisms?
A) Plants
B) Animals
C) Fungi
D) Bacteria
Answer: B) Animals
4. What structure forms the channel in plasmodesmata?
A) Tubulin filaments
B) Desmotubules
C) Actin filaments
D) Keratin fibers
Answer: B) Desmotubules
5. Gap junctions are composed of what protein?
A) Actin
B) Myosin
C) Connexins
D) Keratin
Answer: C) Connexins
6. Plasmodesmata connect which parts of adjacent plant cells?
A) Plasma membranes only
B) Nuclei
C) Cytoplasms
D) Cell walls only
Answer: C) Cytoplasms
7. What is the functional equivalent of plasmodesmata in animal cells?
A) Tight junctions
B) Adherens junctions
C) Gap junctions
D) Desmosomes
Answer: C) Gap junctions
8. Gap junctions allow the passage of which of the following?
A) Proteins
B) Small molecules and ions
C) DNA
D) Lipids
Answer: B) Small molecules and ions
9. Which of the following is a structural feature of plasmodesmata?
A) Connexons
B) Tight seals
C) Desmotubule
D) Protein plaques
Answer: C) Desmotubule
10. In gap junctions, the channels formed by connexins are called?
A) Pores
B) Connexons
C) Tubules
D) Vesicles
Answer: B) Connexons
11. What is a primary role of gap junctions in cardiac muscle?
A) Preventing cell adhesion
B) Facilitating rapid electrical signaling
C) Providing structural integrity
D) Synthesizing proteins
Answer: B) Facilitating rapid electrical signaling
12. Plasmodesmata traverse through which plant cell structure?
A) Plasma membrane only
B) Cell wall
C) Central vacuole
D) Chloroplast
Answer: B) Cell wall
13. Gap junctions are absent in which of the following tissues?
A) Cardiac muscle
B) Nervous tissue
C) Skeletal muscle
D) Epithelial tissue
Answer: C) Skeletal muscle
14. What distinguishes plasmodesmata from gap junctions?
A) They are found in animal cells only
B) They allow DNA transfer
C) They connect plant cells via cytoplasmic bridges
D) They are composed of connexins
Answer: C) They connect plant cells via cytoplasmic bridges
15. Which molecule is too large to pass through gap junctions?
A) Ions
B) Glucose
C) Proteins
D) cAMP
Answer: C) Proteins
16. Plasmodesmata often transport which of the following between cells?
A) Proteins and RNA
B) Lipids
C) DNA only
D) None of the above
Answer: A) Proteins and RNA
17. Gap junctions can be found in which animal tissues?
A) Bone tissue
B) Cardiac and nervous tissue
C) Cartilage only
D) Adipose tissue
Answer: B) Cardiac and nervous tissue
18. What closes gap junctions under pathological conditions?
A) Calcium ion influx
B) Sodium ion depletion
C) ATP binding
D) Low glucose levels
Answer: A) Calcium ion influx
19. Plasmodesmata are lined with what membrane?
A) Inner nuclear membrane
B) Plasma membrane
C) Endoplasmic reticulum
D) Mitochondrial membrane
Answer: B) Plasma membrane
20. How do plasmodesmata differ from gap junctions in structure?
A) Plasmodesmata are made of connexins
B) Plasmodesmata traverse cell walls
C) Gap junctions connect cytoplasm through desmotubules
D) Gap junctions allow protein passage
Answer: B) Plasmodesmata traverse cell walls
21. The number of connexins required to form a connexon is?
A) 4
B) 6
C) 8
D) 10
Answer: B) 6
22. Which of the following can block gap junction communication?
A) Low calcium levels
B) High glucose concentration
C) Excessive ROS
D) Lack of ATP
Answer: C) Excessive ROS
23. Which organelle is closely associated with plasmodesmata?
A) Golgi apparatus
B) Endoplasmic reticulum
C) Mitochondria
D) Lysosomes
Answer: B) Endoplasmic reticulum
24. What happens to plasmodesmata during cell differentiation?
A) They proliferate
B) They are degraded
C) They fuse with the vacuole
D) They close temporarily
Answer: D) They close temporarily
25. Gap junctions in nervous tissue are responsible for?
A) Myelin formation
B) Synaptic signaling
C) Electrical coupling of neurons
D) Neurotransmitter storage
Answer: C) Electrical coupling of neurons
26. Which plant hormone can move through plasmodesmata?
A) Auxin
B) Cytokinin
C) Ethylene
D) Abscisic acid
Answer: A) Auxin
27. What is the approximate size limit for molecules passing through gap junctions?
A) 10 kDa
B) 100 kDa
C) 500 Da
D) 1 kDa
Answer: D) 1 kDa
28. Which cellular condition leads to plasmodesmata widening?
A) Low turgor pressure
B) Pathogen attack
C) High light intensity
D) High nutrient availability
Answer: B) Pathogen attack
29. Gap junctions facilitate synchronization of?
A) DNA replication
B) Cellular metabolism
C) Protein synthesis
D) Cell wall formation
Answer: B) Cellular metabolism
30. Plasmodesmata and gap junctions both allow for?
A) Transfer of entire organelles
B) Communication between adjacent cells
C) Protein synthesis
D) ATP generation
Answer: B) Communication between adjacent cells
