Biology Test 4-5

Evidence that all living cells have a common origin is provided by

Basic similarities in cell structure and chemistry

Which of the following are forms of carrier-mediated transport?

Both facilitated discussion and carrier-mediated active transport.

Which of the following pics is correctly matched?

Centrist me-cell division

DNA is associated with proteins, forming a complex called

Chromatin

A transmembrane protein differs from other membrane proteins because it:

Completely extends through the membrance

One function of peroxisomes involves the process of

Detoxification

The passive movement of a substances along its concentration gradient is termed.

Diffusion

The force necessary to cause micro tubules of cilia and flagella to slide alongside one another is provided through the action of ____ proteins, which derive the energy to perform their work directly from ____ molecules

Dynein; ATP

The presses illustrated in Figure 5-2 is called:

Exocytosis

Biological membrance are one dimensional fluids

False

Enzymes called pro teases in the ER lumen catalyze folding of proteins into proper conformations?

False

In the sodium-potassium pump, sodium - ion release causes two K+ ions to be released into the cell.

False

Mitochondria play an important role in cell necrosis

False

The smooth ER is the primary site for the synthesis of proteins and cholesterol needed to make membrances

False

Which of the following statements about Figure 4-1 is true?

Figure B has a smaller surface area to volume ratio than figure A

You want to determine the location of a specific protein in a cell is using a colored stain. Which of the following is the best technique for this purpose?

Fluorescence microscopy

Plasmodesmata of plant cells are functionally equivalent to ___ of animal cells.

Gap junctions

The scanning electron microscope differs from the transmission electron microscope in that the scanning electron microscope:

Gives a three dimensions image of the objects being studied.

Proteins made on ribosomes may be further modified within the

Golgi Complex

The princess illustrated in Figure 5-2 would most likely be used to transport

Hormones

In a lipid bilayer,____ fatty acid tails face each other within the bilayer and form a region that excludes water

Hydrophobic

A witted flower placed in a vase of water for several hours became stiff and stood erect. When it was placed in a salt solution, it wilted. From this information we can say that the cells of the flower are:

Hypertonic to fresh water, but hypotonic to the salt solution.

Which of the following pairs is correctly matched?

Integrity - Receptors

A key discovery that weakened the Davson - Danielli 'sandwich' model of cell membranes was that:

Membrane proteins were not uniform and did not form flattened sheets.

All of the following is(are) located between the primary walls of adjacent cells?

Middle lamella

Which of the following organelles plays an important role in apoptosis or programmed cell death?

Mitochondria

Which of the following functions would most likely to be occurring in the structure surrounded by the box in Figure 4-2

Molecular chaperone activity.

Catalysts are reusable. Enzymes are protein catalysts, and are reusable. Select the protein(s) below that is(are) not used up by the process carried out.

Na+/K+ pump carrier proteins, aquaporins, and also proteins involved in facilitated diffusion

A single cell Ina smoker's lung has become cancerous. It doubles its DNA and divides much faster than a normal lung cell. The most likely change that would have caused this condition took place in the:

Nucleus

Which of the following molecules is LEAST likely to cross a cellular Membrane by simple diffusion?

Potassium Ion

If a toxin, such as a bacterial toxin, destroys ribosomes, what cellular activity will be affected first?

Proteins synthesis

Nucleoli contain chromosomal regions that specialize in making

RNA

Membrane-bounded organelles facilitate faster chemical reactions because

Reactants are within close proximity to each other.

Differential centrifugal ion is a process that

Separates components of the cell that have different densities

A bottle of perfume is opened on the opposite side of the room and within minutes you begin to smell the perfume. This phenomenon is a classic example of.

Simple diffusion

Simple diffusion may involve the movement of ___ through the plasma membrane down a concentration gradient

Small nonpolar molecules

Which of the following descriptions or structures does NOT match the cell type?

Smallest cell are egg cells

In cells that are constantly involved in secretion, an equivalent amount of membrane must be returned to the interiors of the cell for each vehicle that fuses with the plasma membrane; if this does not occur, then what would happen?

The cell surface will keep expanding.

Which of the following statements explaining the differences in number and types of peripheral proteins found on the inner and outer surfaces of cell membrane is correct?

The functions of the membrane differ on the inside and outside of the cell.

Although glucose molecules constantly diffuse into a cell along their concentration gradient, equilibrium is never reached and glucose continues to enter the cell. This is a direct result of:

The rapid and continuous intracellular formation of glucose phosphates.

Refer to Figure 5-1: Which of the following statements about the red blood cells in Figure B is true?

These red blood cells have shrunken in response to a hypertonic external solution.

Which of the following statements about lipid bilateral is FALSE?

They are inflexible

Which of the following is NOT a characteristic of aquaporins?

They cause dehydration

Which of the following statements concerning centrioles is FALSE?

They have 9+2 arrangement of microtubes

During an infection, white blood cells travel to the infected site and phagocytize the pathogens. After phagocytosis, primary lysosomes fuse with the he phagocytic vesicle to form a larger vesicle called a secondary lysosomes. The reason for this is

To mix the pathogens with strong hydrolysis enzymes and destroy them

In the merchandise of action of a proton pump, the role of ATP is to

Transfer protons to the outside of a cell

In animal cells the main microtubule organizing center (or centrosome) is important in cell division

True

Sodium-potassium pumps maintain an electrochemical gradient

True

One difference between tight junction and dermatomes is that tight junctions

Are regions where the plasma membrane from two neighboring cells are in actual contact.

Penicillin is toxic to certain dividing bacterial cells because it prevents cell wall formation, causing the cells to burst. This indicates that the bacteria live in

A hypotonic medium