Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis?
1. Disruption of one of these types of structure should necessarily disrupt each of the others as well.
2. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.
3. Motor proteins such as dynein must have evolved before any of these four kinds of structure.
4. Natural selection for motility must select for microtubular arrays in circular patterns.
The presence of cholesterol in the plasma membranes of some animals.
1. enables the membrane to stay fluid more easily when cell temperature drops.
2. enables the animal to remove hydrogen atoms from saturated phospholipids.
3. enables the animal to add hydrogen atoms to unsaturated phospholipids.
4. makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
Prokaryotic cells have something unique in the form of:
(1) Inclusion bodies
(3) Cell wall
(4) 70 S ribosomes
Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes?
1. a cell that is secreting proteins
2. a cell that is producing cytoplasmic enzymes
3. a cell that is constructing its cell wall or extracellular matrix
4. a cell that is digesting food particles
Gas vacuoles allow cyanobacteria to:
1. Store carbon dioxide for assimilation
2. Control their buoyancy
3. Provide anaerobic conditions to nitrogenase
4. Eliminate toxic ammonia
The lipid component of the plasma membrane mainly consists of:
The endomembrane system of a eukaryotic cell includes all except:
4. Golgi complex
Carotenoid pigments are found in:
(1) Only I
(2) Only I and II
(3) Only II
(4) I, II and III
Microbodies, which help to convert stored lipids into carbohydrates so they can be used for plant growth, are known as: