Bio

Why is it advantageous for cells to be small?

A small cell has a small volume relative to surface area, thereby increasing efficient transport.

What does the process of differential centrifugation achieve?

It separates components of the cell that have different densities.

How does the scanning electron microscope differ from the transmission electron microscope?

The SEM gives a three dimensional image of the object being studied.

Which statements about centrioles is false?

They have a 9 + 2 arrangement of microtubules.

What cellular structure is unique to plant cells and some photosynthetic fungi?

chloroplasts

DNA is associated with RNA and certain proteins, forming a complex called:

chromatin

A glycoprotein destined for secretion from the cell would move through the Golgi complex which sequence?

cis face to medial region to trans face

Plants lack organ systems for disposing of toxic metabolic waste products. Their cells' vacuoles are like what animal cell organelle?

lysosomes

DNA must transcribe its information into what type of molecule before leaving the nucleus and entering the cytoplasm?

mRNA

What two organelles are both responsible for converting energy into forms that can be used by cells?

mitochondria and chloroplasts

What enzyme in the ER lumen catalyze the efficient folding of proteins into proper conformations?

molecular chaperones

A single cell in a 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

What is one cellular characteristic found in all prokaryotic and eukaryotic cells?

plasma membrane

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

protein synthesis

What is the microtubule arrangement of a flagellum or cilium?

9 + 2 arrangement

As a result of testing an experimental drip on a vertebrate cell, you notice that the cell cortex becomes more fluid, and although the cell remains strong, it loses its ability to move. Based on this evidence, you correctly conclude that the drug most directly affected:

actin filaments

Which organelle can be considered a sorting, processing and packaging center?

Golgi complex

Proteins made on ribosomes may be further modified within which organelle?

Golgi complex.

What is the primary function of mitochondria?

transformation of energy

Which cellular structure is correctly matched to the role it plays within the cell?

centrosome−cell division

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

degrade the bacteria and export it from the cell.

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

fluorescence microscopy

What protects a cell and may help keep other cells at a distance?

glycocalyx

The ratio of the size of the image seen with the microscope to the actual size of the object is called:

magnification.

What is found between the primary walls of adjacent cells for cells to adhere tightly to one another?

middle lamella

What does the nucleolus, within the nucleus, synthesize?

ribosomal RNA

The accompanying image is the product which type of microscope?

scanning electron microscope

Evidence that all living cells have a common origin is best illustrated by the:

basic similarities in cell structure and chemistry.