BIOL 2457 EXAM; 1 (CH-3) QUESTIONS WITH CORRECT ANSWERS

BIOL 2457 EXAM: 1 (CH-3) QUESTIONS WITH
CORRECT ANSWERS 2026/2027
3 Major Parts of a cell - CORRECT ANSWER

-1. plasma membrane

2. cytoplasm

3. nucleus



largest organelle - CORRECT ANSWER -nucleus



body fluids - CORRECT ANSWER -Interstitial fluid, blood plasma, CSF. Act as an transport and
dissolving media



cell secretion - CORRECT ANSWER -gastric juices, saliva, mucus, etc. Aid in lubrication and
digestion.



fluid mosaic model - CORRECT ANSWER -phospholipid bilayer with embedded proteins



Phospholipids - CORRECT ANSWER -polar phosphate head, non-polar fatty acid tails (75%)



Cholesterol - CORRECT ANSWER -Stabilizes the membrane, phospholipid mobility, and
membrane fluidity. (20%)



Glycolipids - CORRECT ANSWER --Polar sugar groups, non-polar fatty acids

-outer membrane only (5%).

, integral membrane proteins - CORRECT ANSWER -firmly embedded in the transmembrane
protein.



Peripheral Proteins - CORRECT ANSWER --Loosely attached to integral proteins

-Include cytoskeleton and extracellular matrix proteins, and motor proteins.



Glycoproteins - CORRECT ANSWER --abundant proteins w/ sugar groups.X2 X2 X2 X2 X2 X2 X2 X2




-cell-cell interactions and recognition.
X2 X2 X2




-part of glycocalyx
X2 X2




3 factors that bind cells together - CORRECT ANSWER -1. Glycocalyx
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




2. wavy shape of cell membranesX2 X2 X2 X2




3. cell junctions X2




tight junctions - CORRECT ANSWER --Impermeable
X2 X2 X2 X2 X2




-prevent leakage of extracellular fluid across a layer of epithelial cells.
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




-occludins in membranes of adjacent cells X2 X2 X2 X2 X2




Desmosomes - CORRECT ANSWER --Anchoring junctions that prevent cells from being pulled apart
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




- intermediate (Keratin Filaments), Linker (Cadherin) proteins.
X2 X2 X2 X2 X2 X2




gap junctions - CORRECT ANSWER -
X2 X2 X2 X2 X2




(communicating junctions) provide cytoplasmic channels between adjacent cells by connexons.
X2 X2 X2 X2 X2 X2 X2 X2 X2




plasma membrane - CORRECT ANSWER -A selectively-
X2 X2 X2 X2 X2 X2




permeable phospholipid bilayer forming the boundary of the cells.
X2 X2 X2 X2 X2 X2 X2 X2