Histology - Cell structure and function

Question 1

size range of most mammalian cells ?

Answer 1

10 to 100 micrometers

Question 2

bacterial cells typical size?

Answer 2

1 micrometer

Question 3

size of a RBC

Answer 3

7um (6 to 8)

Question 4

How is cell specialization is possible if each cell derives from the same precursor cell containing the same genetic material?

Answer 4

it is achieved by a particular gene expression pattern that may vary over time, but whose pattern defines the very nature of a cell type. Genes can be switched on and off at any time in cells, and the pattern in which this happens defines the function of a particular cell

Question 5

On what depended the evolution of large multicellular organism

Answer 5

it depended on the ability of eukaryotic cells to express their heriditary information in many different ways and to function cooperatively

Question 6

what is an eukaryotic cell

Answer 6

any cell or organism that possesses a clearly defined nucleus

Question 7

A part from cells, what comprises the human body?

Answer 7

Extracellular material and extracellular fluid

Question 8

What can contain intercellular material and fluid?

Answer 8

many dissolved metabolites, ions and soluble molecules and proteins

Question 9

do cells in complex organism exist alone?

Answer 9

not usually. They are grouped together in a precise manner to fulfill specific, requisite physiological functions

Question 10

What are the 4 main types of tissus comprised in the body? Or what are the four primary tissues formed by cells?

Answer 10

• Epithelium
• connective tissue
• muscle tissue
• nervous tissue

Question 11

What is the usual histology of organs

Answer 11

Most often, all four tissue types are present in a single organ.

Question 12

on what rely the organized pattern of cells to form tissues?

Answer 12

on cell adhesion and cohesion

Question 13

What are organelles

Answer 13

Organelles are small structures found within cells (precisely in the cytoplasm) that perform very specific tasks. They are insoluble, structural and functional component of a cell

Question 14

Can we visualise organelle? What size range?

Answer 14

Most organelles are in the sub-micrometer range and can only be visualized by electron microscopy, but some such as the nucleus and the Golgi apparatus can be observed with the light microscope

Question 15

Where are found organelle ?

Answer 15

within the cytoplasm of a cell

Question 16

What is the protoplasm ?

Answer 16

A gel like substance that can be subdivided into the karyoplasm (nucleoplasm) of the nucleous that sourrounds the DNA, and the cytoplasm.

Question 17

Where is located the cytoplasm ?

Answer 17

between the cell membrane and the nucleus

Question 18

What is the cytosol ?

Answer 18

the fluid component of the cytoplasm that contain many soluble organic and inorganic molecules

Question 19

what is the membrane system of a cell?

Answer 19

The outer membrane (phospholipid bilayer membrane) comprising the protoplasm AND an internal set of membranes that define many intracellular organelles.

Question 20

is the outer cell membrane permeable?

Answer 20

Selectively permeable!

Question 21

What determines the fluidity of phospholipid bilayers?

Answer 21

The amount of cholesterol they contain - with more cholesterol making them less fluid

Question 22

can the molecules residing in the cell membrane can move?

Answer 22

Yes, they can move as requested by the function or demands placed on a given cell

Question 23

Describe the cell membrane lipids

Answer 23

Lipid bilayer : inner leaflet and outer leaflet. They have a polar hydrophilic side and nonpolar hydrophobic side.

Question 24

what does the hydrophilic/hydrophobic by-layer permits?

Answer 24

it permits a self-sealing property to the membrane

Question 25

what is the most common molecule in membranes?

Answer 25

phospholipid

Question 26

describe phospholipid

Answer 26

have a polar head group of glycerol and two hydrophobic hydrocarbon tails that are usually fatty acids