Bio 231 @ Oit - Lecture 2 Quizes

Front 1

Explain the difference between diffusion and osmosis?

Back 1

Diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration. Substance travels down their concentration gradients eventually achieving equilibrium. The cell membrane is a semi-permeable barrier; it will allow certain substances to pass through the membrane and halt the passage of other substances. The concentration of a solution inside or outside the cell will determine the net movement of water (osmosis) across the membrane. Hydrostatic pressure is the amount of force generated by the water as it crosses the plasma membrane and enters the new compartment. Osmotic pressure is the amount of pressure necessary to prevent movement of water across the membrane, the pressure required to oppose osmosis. If the concentrations of the two solutions across the cell membrane are different, water will move across the membrane in an attempt to balance these two concentrations

Front 2

How does active transport differ from simple diffusion?

Back 2

Simple diffusion which is a form of passive transport requires no energy or carrier molecule. Ions will require an ion channel, however, other molecules which are small or have no electrical charge can pass through individual phospholipid molecules. The
driving force behind diffusion is the concentration gradient.
Facilitated diffusion also requires no energy; the driving force is also the concentration gradient. This type of membrane transport requires a transport protein.
Active transport involves the movement of a substance from an area of low higher concentration to an area of higher concentration. Substances travel against their own concentration gradient (swim against the current).

Front 3

What is the difference between osmotic and hydrostatic pressure?

Back 3

Hydrostatic pressure is the amount of force generated by the water as it crosses the plasma membrane and enters the new compartment.
Osmotic pressure is the amount of pressure necessary to prevent
movement of water across the membrane, the pressure required to oppose osmosis.

Front 4

If a red-blood cell is placed in a hypotonic solution, what will happen to the cell and why?

Back 4

Hypotonic solution- the cytosol is more concentrated that the extracellular fluid, water will move into cell in order to make solutions equal. The plasma membrane and cell can only swell so much (similar to forcing air into a balloon). Eventually the plasma membrane will rupture or lysis.

Front 5

With respect to metabolism, what is the role of the mitochondria?

Back 5

Mitochondria are threadlike or sausage-shaped membranous organelles. The are the power plants of a cell, providing most of its ATP supply.

Front 6

Epithelia tissues are highly vascular (T or F).

Back 6

False - Epithelial tissues are Avascular, but innervated.

Front 7

What type of cell junction allows for the passage of small molecules and ions?

Back 7

Gap junctions

Front 8

What is the purpose of microvilli?

Back 8

They increase the plasma membrane surface area tremendously and are most often found on the surface of absorptive cells such as intestinal and kidney tubule cells.

Front 9

List the three characteristics which best describes an epithelial cell?

Back 9

1. Polarity, 2. Specialized contacts, 3. Supported by connective tissue, 4. Avascular but innervated, 5. Regeneration

Front 10

What is the benefit of stratified epithelium?

Back 10

Epithelium has a high regenerative capacity. Some epithelia are exposed to friction and their surface cells rub off. Others are damaged by hostile substances in the external environment. If and when their apical basal polarity and lateral contacts are destroyed, epithelial cells begin to reproduce themselves rapidly. As long as epithelial cells receive adequate nutrition, they can replace lost cells by cell division.

Front 11

Why is an intact epidermal layer so important?

Back 11

Protection, the external covering of the body (skin) but also the various cavities (oral, rectal, vaginal) and the internal organs (serous membranes).

Front 12

Which embryonic germ layer gives rise to muscle and bone?

Back 12

Embryonic Connective Tissue – known as mesenchyme; these cells are undifferentiated, meaning they have the potential of forming other types of connective tissue during embryonic development.

Front 13

List the functions of connective tissue.

Back 13

Binding – tendons will secure muscle to bone, ligaments hold individual bones together (acromioclavicular ligament of the pectoral girdle) and fibrous connective tissue binds the integument to underlying structures.
Support – both bone and cartilage provide internal support to various structures.
Movement – the bone of the skeleton furnish an internal frame allowing for the attachment of various muscle groups. The organization of extensor and flexor groups associated with various joints makes gross motor
movement possible.
Protection – hard connective tissue such as bone can protect delicate soft tissue from external damage (cranium, vertebrae, and ribs).
Mineral Storage – the matrix of bone functions as a storage site for calcium and phosphate ions, both important for various physiological functions.
Transportation – this is accomplished by the efforts of the circulatory system especially the blood, both RBC and blood plasma.
Energy Storage – adipose tissue contains numerous fatty acid chains which can be used in the Krebs cycle for ATP production.

Front 14

What is located within the matrix of connective tissue?

Back 14

the matrix of bone functions as a storage site for calcium and phosphate ions, both important for various physiological functions.

Front 15

What is the difference between fibrous and supportive connective tissue?

Back 15

Fibrous Connective Tissue – the presence of fibrous proteins defines this subclass.
Supportive Connective Tissue – this tissue provides internal support and gives shape to various structures.

Front 16

Which statement is false regarding active transport?
a. Requires an expenditure of energy
b. Substances are transported down their concentration gradient
c. Requires some type of pumping mechanism
d. This type of membrane protein is an integral or transmembrane protein

Back 16

b. Substances are transported down their concentration gradient

Front 17

The movement of water across the cell membrane is called:
a. Simple diffusion
b. Exocytosis
c. Faciltative transport
d. Osmosis

Back 17

d. Osmosis

Front 18

Which of the following solutions has the highest solute content?
a. Isotonic
b. Hypotonic
c. Hypertonic
d. Osmotic

Back 18

c. Hypertonic

Front 19

When a red blood cell (RBC) is placed in an isotonic solution, what will occur?
a. No apparent change to the RBC
b. Water enters the RBC, followed by cell lysis
c. Water exits the cell, followed by crenation
d. The cell wall maintains the shape of the cell

Back 19

a. No apparent change to the RBC

Front 20

The primary function of the mitochondria is:
a. Coordinating protein synthesis
b. Storage vesicle for digestive enzymes
c. Primary site for the synthesis of ATP
d. Organelle which contain the genetic instructions for the cell

Back 20

c. Primary site for the synthesis of ATP

Front 21

Osmotic pressure is best defined as:
a. The pressure of water against the cell membrane
b. The amount of pressure necessary to prevent the entry of water into a cell
c. The force generated as water enters a cell
d. The amount of pressure generated as water exits a cell

Back 21

b. The amount of pressure necessary to prevent the entry of water into a cell

Front 22

Which of the following is not a function of epithelial tissue?
a. Secretion
b. Protection
c. Support
d. Filtration

Back 22

c. Support

Front 23

Which of the following is not a characteristic of epithelial tissue?
a. Damaged cells are replaced through mitosis
b. Composed primarily of cells and little extracellular matrix
c. Exhibits various types of cellular contacts
d. Tissues are highly vascular

Back 23

d. Tissues are highly vascular

Front 24

Epithelial cells which have equal dimensions (width, height, depth) are described as:
a. Pseudostratified
b. Squamous
c. Cuboidal
d. Columnal

Back 24

c. Cuboidal

Front 25

What type of cell junction allows for the passage of small molecules and ions?
a. Tight junctions
b. Desmosome
c. Gap junctions
d. Intercalated disc

Back 25

c. Gap junctions

Front 26

What type of glad has no duct?
a. Sebaceous gland
b. Endocrine gland
c. Oil gland
d. Exocrine gland

Back 26

b. Endocrine gland

Front 27

What embryonic germ layer will give rise to the lining of the digestive tube?
a. Ectoderm
b. Mesoderm
c. Epiderm
d. Endoderm

Back 27

b. Mesoderm

Front 28

This type of cellular modification enhances the function of absorption
a. Cilia
b. Free surface
c. Microvillus
d. Intestinal villi

Back 28

c. Microvillus

Front 29

Which of the following epithelial would be best for absorption?
a. Pseudostratified ciliated columnar
b. Stratified squamous
c. Simple columnar
d. Transitional

Back 29

a. Pseudostratified ciliated columnar

Front 30

An intact epidermal (skin) covering:
a. Allows for increased cellular contact and molecular exchange
b. Protects the skin for desiccation and bacterial infection
c. Promotes cellular replacement (mitosis)
d. Increases the filtration process

Back 30

b. Protects the skin from desiccation