Cell Modifications

Question 1

a process that occurs after cell division where the newly formed cells are structurally modified so that they can perform their function efficiently and effectively.

Answer 1

Cell modification

Question 2

type of cell modification that is found on the apical surface of the cell

Answer 2

Apical Modifications

Question 3

Functions may include secretion, absorption, movement of luminal contents, locomotion, sensing, and in some organisms, ingestion

Answer 3

Apical Modifications

Question 4

a. Villi/Microvilli
b. Pseudopods
c. Cilia
d. Flagella
e. Root hair

Answer 4

Apical Modifications

Question 5

Function for intercellular connections with the adjacent/neighboring cells

Answer 5

Lateral Modifications

Question 6

a. Tight Junctions
b. Adherens/Adhering Junction
c. Gap Junction

Answer 6

Lateral Modifications

Question 7

Found on the basal surface of the cell for anchorage and/or attachment

Answer 7

Basal Modifications

Question 8

a. Desmosomes
b. Hemidesmosomes
c. Basal infoldings

Answer 8

Basal Modifications

Question 9

Structure:
- Finger-like cytoplasmic extensions
- Each villus has lacteal (tiny lymphatic vessels that absorb
fatty acids and glycerol)
- One-cell thick to increase the diffusion rate
- Has blood capillary that absorbs glucose and amino acids
- Cells on the villi are packed with microvilli

Answer 9

villi

Question 10

Present in:
- Apical surface of epithelial cells like in small intestine

Answer 10

villi

Question 11

Functions:
- Provides a short distance for the diffusion of food molecules in the blood
- Increases surface area for absorption

Answer 11

villi

Question 12

Structure:
- Elongated, motile structures on the surface of some epithelial cells; short hair-like projections
- Made up of microtubules (axoneme: central core)
- Each cilium is connected to a basal body and extends from the free surface
- Exhibits rapid back-and-forth movement

Answer 12

cilia

Question 13

Present in:
- Ciliates like Paramecium and Balantidium, mammalian oviduct (respiratory tract: lungs, trachea, paranasal sinus mucosa, primary bronchus)

Answer 13

cilia

Question 14

Functions:
- move mammalian ova through oviducts
- clean debris from the respiratory systems of mammals
- locomotion (for protozoa)

Answer 14

cilia

Question 15

Structure:
- Tail-like projections that protrude from the cell body
- Bundle of nine pairs of microtubules surrounding two
central microtubules
- Same axial structure with cilia but much longer

Answer 15

flagella

Question 16

Present in:
- Sperm cell (spermatozoa- only flagellated cell in human
body)
- Mastigophora: Trypanosoma, Trichomonas, Giardia leishmania
- also occur on the gametes of algae, fungi, mosses and
slime molds

Answer 16

flagella

Question 17

Function:
- locomotion

Answer 17

flagella

Question 18

Structure:
- Long tubular-shaped outgrowths from root epidermal cells
- about 10 micrometers in diameter

Answer 18

root hair

Question 19

Present in:
- Plant roots

Answer 19

root hair

Question 20

Function:
- Aid in plant nutrient acquisition, anchorage, and microbe
interaction
- increase the root’s surface area.

Answer 20

root hair

Question 21

Structure:
- intercellular adhesion complexes (predominantly two proteins called claudins and occludins) in epithelia and endothelia

Answer 21

tight junctions

Question 22

Present in:
- organs (such as skin), blood vessels, and cavities.
- Bladder and intestine

Answer 22

tight junctions

Question 23

Function:
- Form the border between the apical and basolateral cell
surface domains
- establish a barrier that prevents extracellular fluid across a
layer of epithelial cells.
- Prevents leakage of the contents

Answer 23

tight junctions

Question 24

Structure:
- Has cadherin receptors that bridge the neighboring plasma
membranes

Answer 24

adherens junction

Question 25

Present in:
- Just below tight junctions; epithelial tissues

Answer 25

adherens junction

Question 26

Function:
- maintain the physical association between cells
- Preserve tissue integrity by linking cells and connecting to
actin filaments

Answer 26

adherens junction

Question 27

Structure:
- composed of two connexons, also known as hemichannels
that line up across the intercellular space.

Answer 27

gap junction

Question 28

Present in:
- epithelia, nerves, cardiac (heart) muscle, and smooth
muscle (such as that of the intestines).

Answer 28

gap junction

Question 29

Functions:
- allow for electrical communication between cells, and also allow the passage of small second messengers.
- when heart cells need to beat in unison, it allows for the transmission of electrical signals between the cells.

Answer 29

gap junction

Question 30

Structure:
- cadherins in the plasma membrane connect to
intermediate filaments

Answer 30

desmosomes

Question 31

Present in:
- skin epidermis lymphatic endothelial cells

Answer 31

desmosomes

Question 32

Functions:
- anchoring sites for ropelike intermediate filaments, which
form a structural framework of great tensile strength
- act like spot welds between adjacent epithelial cells,
connecting them
- maintain the cells in a sheet-like formation in organs and
tissues that stretch, such as the skin, heart, and muscles.
- Offer a little bit of space for stress release.

Answer 32

desmosomes

Question 33

• supports the epithelium and also functions as a passive molecular sieve or ultrafilter.
• These increase surface area for ion transport.
• Present in mitochondria

Answer 33

basal infoldings

Question 34

• Functions similarly to desmosomes but it specifically
  attaches the cell to the basement membrane
• Consists of integrin

Answer 34

hemidesmosomes

Question 35

• cell extensions used for movement and feeding
• They also help in sensing targets which can then be engulfed made up of actin filaments, microtubules and intermediate filaments.
• Commonly present in amoeba

Answer 35

pseudopods