Cell Communication and Differentiation Quiz

Cell Communication and Structure

• Quorum-sensing molecules mediate communication between microorganisms.
• Virulence factors are general traits, not specific ones. Examples include invasion, cell interaction, intracellular survival, and adherence.
• Biofilm is a three-dimensional structure encased in an extracellular matrix.
• Bacterial shapes include round, spiral, rod-shaped, but not branched.

Cell Differentiation and Specialization

• Unipotent cells can differentiate into only one cell type.
• Multicellular organism cell differentiation is coordinated by signal exchange through cells.
• Neurotransmitters facilitate nerve cell signal transmission.
• The endoplasmic reticulum is extensive in neurons and crucial for protein synthesis.
• The sodium-potassium pump (Na+/K+ pump) actively transports Na⁺ and K⁺ across the cell membrane, requiring ATP.
• Differentiation alters a cell's morphology, physiology, and biochemistry, by changing gene expression.
• Red blood cells transport oxygen and carbon dioxide.
• Keratinocytes, enterocytes, and erythrocytes are highly metabolic cells with short lifespans.
• Apicoplast is a non-photosynthetic plastid found in some Apicomplexa parasites.

Specialized Cellular Structures

• Ventral adhesive disk is an attachment organelle on parasitic flagellates like Giardia intestinalis.
• Undulating membrane is a plasma membrane flap found in certain parasitic flagellates like Trypanosoma.
• Karyomastigont is a microtubule system surrounding the nucleus in archamoebae.
• Axostyle is a unique, internal, rod-like structure; it's NOT the microtubule system surrounding the nucleus.
• Nucleomorph is the remnant of the engulfed alga's nucleus in complex plastids of certain algae.
• Actin microfilaments and microtubules are polarized components of the cytoskeleton.
• Kleptoplasts are stolen plastids in Elysia chlorotica slugs.
• Plastids in the Apicomplexa group have two membranes.
• Cellulose synthase is the enzyme complex for cellulose synthesis.
• Intussusception is the growth mode where new cell wall material is deposited between existing layers in primary cell walls during enlargement.
• Myosins are cellular motors moving along actin microfilaments.
• Glyoxysomes convert fatty acids to glucose precursors and contain beta-oxidation enzymes; they are double-membrane organelles in plant cells.
• Peroxisomes are microbodies containing catalase.
• Membranes are selectively permeable.
• Cis pole of the Golgi apparatus receives vesicles from the endoplasmic reticulum.
• t-SNARE and v-SNARE proteins facilitate vesicle fusion.
• Membrane phospholipids are amphipathic.
• Preprophase band of microtubules determines the division plane in cells.
• Examples of cytoskeletal elements include actin microfilaments and microtubules.

Cell Types and Functionality

• Tracheal elements, in plants, do NOT retain a nucleus throughout their life.
• Erythrocytes (red blood cells) lose their nuclei in maturity.
• Neurons retain their nucleus throughout life.
• Etioplast is a chloroplast precursor in leaves grown in darkness.
• Sarcoplasmic reticulum is associated with muscle cells.
• Stromules are dynamic extensions of plastids.
• Protein interactions are key to targeted Golgi vesicle transport.

Cellular Signaling and Responses

• Amplification is a fundamental property of cell signaling, where one ligand activates many second messengers.
• Acetylcholine has different effects on different cells due to diverse receptor types, and thus, distinct receptor-ligand interactions.