68) Microtubules
A) usually composed of myosin.
B) hollow, filamentous structures.
C) attach : 1200443.
68) Microtubules
A) are usually composed of myosin.
B) are hollow, filamentous structures.
C) attach the plasma membrane to the underlying cytoplasm.
D) interact with filaments composed of tubulin to produce muscle contractions.
E) are found on the ribosomes.
69) The cellular organelle responsible for removing and recycling damaged or denatured proteins is called the
A) mitochondrion.
B) nucleus.
C) nucleolus.
D) Golgi apparatus.
E) proteasome.
70) Which of the following is a function or property of the mitochondria?
A) ATP production
B) physical isolation
C) regulation of exchange with the environment
D) sensitivity
E) structural support
71) Which of the following contains an unusual double membrane?
A) mitochondrion
B) nucleolus
C) Golgi apparatus
D) peroxisome
E) lysosome
72) If a cell lacked centrioles, it probably would not be able to
A) move.
B) produce DNA.
C) divide.
D) synthesize proteins.
E) metabolize sugars.
73) When a protein is synthesized on fixed ribosomes, it is threaded into the lumen of which structure(s)?
A) endoplasmic reticulum
B) the Golgi apparatus
C) nucleoli
D) transport vesicles
E) secretory vesicles
74) Tubulin is to microtubules as myosin is to
A) thin filaments.
B) microvilli.
C) actin.
D) flagella.
E) thick filaments.
75) Examination of a sample of cells reveals large numbers of mitochondria compared to most other cells. Which of the following is a likely reason for this?
A) The cells produce digestive enzymes.
B) The cells produce steroid hormones.
C) The cells have very high energy requirements.
D) The cells synthesize transport proteins.
E) The cells make antibodies.
76) The cell’s ribosomal RNA (rRNA) is produced by the
A) ribosomes.
B) nucleoli.
C) lysosomes.
D) smooth endoplasmic reticulum.
E) Golgi apparatus.
77) The control center for cellular operations is the
A) ribosome.
B) nucleolus.
C) smooth endoplasmic reticulum.
D) Golgi apparatus.
E) nucleus.
