Chapter 1.2

Question 1

What is the main difference between eukaryotic cells and prokaryotic cells

Answer 1

Eukaryotic
->they contain a true nucleus enclosed in a membrane

Prokaryotic
->they do not contain a TRUE nucleus

Question 2

How do eukaryotic cells reproduce

Answer 2

-they reproduce through the process of mitosis

Question 3

How many membranes in the nuclear membrane or envelope

Answer 3

-it is a double membrane

Question 4

What allows for the selective two way exchange between the cytoplasm and the nucleus

Answer 4

-the nuclear pores allows for this

Question 5

Describe the relation between histones and linear DNA

Answer 5

• linear DNA is bound around histone proteins

- >they are then wound around further to result in linear strands called chromosomes

Question 6

Where is the ribsosomal RNA(rRNA) synthesized?

Answer 6

• it is synthesized in the nucleolus
• > the nucleolus is the darker spot in the nucleus
• > takes up about 25% of the nucleus

Question 7

What is the function of the outer membrane of the mitochondria

Answer 7

-it serves as a barrier between the cytosol and the inner environment of the mitochondrion

Question 8

What is the function of the inner membrane of the mitochondrion

Answer 8

• it is organized into foldings called cristae
• > contains molecules/enzymes necessary for the electron transport chain

-note the cristae increases the surface area available for the electron transport chain enzymes

Question 9

What is the space between the inner and outer mitochondrion membranes

Answer 9

-this space is referred to as the intermembrane space

Question 10

What is the space inside the inner mitochondrion membrane referred to as

Answer 10

-it is referred to as the matrix

Question 11

What is meant by the term cytoplasmic inheritance or extranuclear inheritance? Give an example

Answer 11

• it is described as the genetic transmission of material independent of the nucleus
• > eg; mitochondria

Question 12

What are lysosomes?

Answer 12

• they are membrane bound structures
• > containing hydrolytic enzymes
• > break down many substrates

Question 13

What are endosomes and which organelles do they cooperate with

Answer 13

• they are organelles
• > that transport, package and sort cell material to and from the cell membrane

-they work together with the cell membrane, the TRANS golgi and the lysosomes for degradation

Question 14

What is meant by the term autolysis? What does it ultimately result in?

Answer 14

• it is the release of enzymes from the lysosome
• > ultimately results in apoptosis
• > as there are hydrolytic enzymes

Question 15

What is the smooth ER used for?

Answer 15

• they lack ribosomes
• > so they are used primarily for lipid synthesis
• > eg; phospholipids in the cell membrane

-they are also used for the detoxification of certain drugs and poisons

Question 16

What are peroxisomes? What are their function

Answer 16

• they contain hydrogen peroxide
• > they primarily breakdown long chain fatty acids via BETA oxidation
• they are also involved in synthesis of phospholipids
• > contain some enzymes involved in the pentose phosphate pathway

Question 17

What are the functions of the cytoskeleton? Also name the three types of cytoskeletons

Answer 17

• they provide structure to the cell and helps maintain the shape of the cell
• they also provide a conduit for the transport of materials around the cell

Question 18

What are microfilaments? How do they help the cell? What are they made up of?

Answer 18

• they are made up of solid polymerized rods of actin
• > not hollow
• they help the cell with resistance of compression
• > they also provide protection for the cell

-actin works in unison with myosin as well to generate muscle movement

Question 19

Do microfilaments play a role in cytokinesis

Answer 19

• yes
• > they are involved in the division of materials between daughter cells
• > they form the CLEAVAGE FURROW between two daughter cells
• > as actin within this cleavage furrow or ring contract, they become smaller
• > eventually pinching off the connection between the two daughter cells

Question 20

What are microtubules? What are their functions in the cells

Answer 20

• they are hollow polymers of tubulin proteins

- >they provide pathways for kinesis and dynein to carry vesicles

Question 21

Do cilia and flagella contain microtubules? What is their unique structure

Answer 21

• yes
• their unique structure is the 9+2 structure
• > 9 pairs of microtubules form the outer ring
• > 2 pairs of microtubules form the center

Question 22

Where are centrioles found?What is their function during mitosis?

Answer 22

• centrioles are found in centrosomes
• > they are the organizing centers for mcirotubules
• during mitosis
• > they go to opposite poles of the cell and organize the mitotic spindle
• > they exert force on kinetochores this way, pulling the sister chromatids apart

Question 23

What are different classes of intermediate filaments? What are they involved in?

Answer 23

• the different classes are keratin, desmin, vimentin and lamins
• they are involved in cell to cell adhesion
• they are also involved in maintaining the cytoskeleton integrity of the cell
• > allows the cell to withstand tension
• > making the cell structure more rigid

-they also anchor organelles organelles like the nucleus

Question 24

What are the four tissue types

Answer 24

1) epithelial tissue
2) connective tissue
3) Muscle tissue
4) Nervous tissue

Question 25

What do epithelial tissues cover? What functions does it serve

Answer 25

- they cover the body and line its cavities - >provide a means against pathogen invasion or dessication - they also are involved in - >absorption, secretion and sensation

Question 26

What are epithelial cells attached to

Answer 26

-they are attached to a connective tissue known as the basement membrane

Question 27

What is meant by the parenchyma? Give examples

Answer 27

- they are the functional parts of the organ - >the epithelia cells make up the parenchyma often times - >eg; nephrons in the kidney, hepatocytes of the liver, etc

Question 28

Are epithelial cells polarized? If so, then what is meant by the term polarized

Answer 28

- yes - means one side faces the lumen - >the other interacts with the underlying blood vessels/structural cells -eg; small intestine cells

Question 29

How to classify epithelia according to the number of layers

Answer 29

One layer ->simple epithelia Multiple layers ->stratified epithelia Multiple layers that seem to be different in height ->pseudostratified epithelia

Question 30

How to classify epithelia according to their shape

Answer 30

- cuboidal - columnar(long and thin) - squamous(flat and scale like)

Question 31

What are connective tissues used for

Answer 31

- they are used for: - >supporting the body - >providing the body with a framework for the eipthelia cells to carry out their functions

Question 32

What is the main difference between epithelial cells and connective tissue cells

Answer 32

Connective tissue cells - >main contributors to the stroma or support structure - >eg; bone, cartilage, tendons, ligaments, adipose tissue and blood Epithelial cells ->contribute to the parenchyma of an organ

Question 33

Do cells in connective tissue secrete materials such as collagen and elastin

Answer 33

- yes | - >these materials form the extracellular matrix