Which of the following microscopes employing electron beams and has 1000 times the resolving power of a light microscope?
|A)||Scanning electron microscope|
|B)||Transmission electron microscope|
The nucleus of the eukaryotic cell functions:
|A)||as the command center for the cell|
|B)||to store the cell's hereditary information|
|C)||to house the nucleolus|
|D)||to selectively allow certain molecules access to the genetic material and to exit to the cytoplasm|
|E)||All of the choices are correct.|
An extensive system of internal membranes, called the ________________, is where carbohydrates and lipids are manufactured, and proteins are made that will be exported from the cell.
______________ function in the collection, packaging, and distribution of molecules made in the cell.
Two organelles that are believed to have once been free-living bacterial cells are __________________ and _________________.
|B)||Golgi complex; endoplasmic reticulum|
Oxidative metabolism takes place in the ___________________ of the cell.
One organelle, called the _______________, contains enzymes that digest worn out parts of cells.
Which organisms do NOT have centrioles?
|A)||Animals and protists|
|B)||Plants and animals|
|C)||Fungi and protists|
|D)||Plants and fungi|
|E)||ALL living cells contain centrioles|
Eukaryotes must organize their microtubules, especially during cell division. What region is responsible for serving as the microtubule-organizing center for ALL eukaryotic cells?
|A)||the nuclear membrane|
Mitochondria and chloroplasts are organelles in eukaryotes that have properties of prokaryotes, suggesting an ancient symbiotic origin.
The nucleoplasm is connected to the cytoplasm through the action of:
Which of the following is not a function of the Golgi apparatus?
|E)||All of these are functions of the Golgi apparatus|
A major function of chloroplasts is to convert the energy of sunlight into carbohydrates.
The three principle fibers of the cytoskeleton are:
|A)||Actin, myosin, and centrioles|
|B)||Actin, tubulin, and myosin|
|C)||Microtubules, microfilaments, and intermediate filaments|
|D)||Proteins, phospholipids, and polysaccharides|
|E)||Vesicles, connector molecules, and molecular motors|
The "9 + 2" architecture of microtubules is associated with which of the following structures?
Plasmodesmata and gap junctions
|A)||allow small molecules and ions to pass rapidly between cells.|
|B)||are both membrane lined channels.|
|C)||are channels about 1 mm in diameter.|
|D)||are present are in small numbers in a cell.|
|E)||are involved in cell recognition in signaling.|
What property must a molecule have to cross a membrane and initiate a response?
|A)||It must have hydrophilic properties|
|B)||It must have hydrophobic properties|
|C)||It must have sulfur in its structure|
|D)||It must degrade DNA|
|E)||It needs to have many alpha helices|