Unformatted text preview: «I: 35) A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma
membrane, and mitochondria. It could be a cell from
a) a bacterium.“
b) an animal, but not a plant.
a plant, but not an animal. ‘a plant or an animal_\/ "
@any kind of organism. 36) Which of the following statements is true?
All membranes are identical A greater proportion of saturated phospholipids would increase membrane ﬂuidity
6The selective permeability of a membrane depends partly on the type of transport
protein present in the membrane
11) Only certain membranes have phospholipids 2)” Some membranes have hydrophobic surfaces exposed to the cytoplasm, while
others have hydrophilic surfaces facing the cytoplasm 37) According to the ﬂuid mosaic model of the plasma membrane, which of the following
statements is TRUE? a) Proteins of the membrane are mostly spread in a continuous layer over the inner and
outer surfaces of the membrane
,b) Membrane phospholipids frequently ﬂip-ﬂop from one side of membrane to the other.
_ ' Phospholipids are sandwiched between two layers of proteins. 7'
5Membrane phospholipids can move laterally along the plane of the membranev ,e)’ Membrane phospholipids are free to depart from the membrane and dissolve in the
surrounding solution. b 38) Some protozoans have special organelles called contractile vacuoles that continuously eliminate excess water from the cell. The presence of these organelles tells you that the
environment a is isotonic to the protozoan
is hypotonic to the protozoan
c) contains a higher concentration of solutes than the protozoan
d) is hypertonic to the protozoan
e) c and d are correct 39) What kinds of molecules pass through a cell membrane most easily?
a) large and hydrophobic
small and hydrophobic
21’) ionic e) monosaccharides such as glucose ...
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- Spring '07