Plant tissues

Question 1

What are the different levels of organization. Explain?

Answer 1

protoplasm- simplest living substance

cells- simplest living unit

tissues- group of specialized cells that perform one or more function

organs- group of different tissues that crate a structure with a special function

systems- group of organs that have closely related functions

organism- plant/ animal with cells, tissues, organs, systems that work together

Question 2

Define differentiation?

Answer 2

process to change structure to become specialized to perform special function

Question 3

plant vs animal differentiation?

Answer 3

animal-embryonic-mitosis-differentiation-organism

plant-meristematic-mitosis-differentiation-special plant tissue

Question 4

define meristematic tissue?

Answer 4

continuously dividing, unspecialized, undifferentiated cells that give rise to all other plant tissues

Question 5

Where is meristematic tissue found? (2)

Answer 5

• apical meristem- primary growth- length at tip of root and stem
• lateral meristem(cambium)- secondary growth- girth of roots and stems

Question 6

What is the structure of meristematic tissue? (5)

Answer 6

• cubic
• small (thin cell walls)
• no intracellular air spaces (dense)
• large nucleus
• no vacoule

Question 7

What is permanent tissue?

Answer 7

cells specialized for specific functions

Question 8

what are epidermal cells?

Answer 8

single layer of cells on the outside of leaves, roots and stems

Question 9

structure and functions of epidermal cells?(3 each)

Answer 9

• thick wall brick shaped - protect from viruses etc…
• cuticle on top- prevent water loss
• large vacuole
• transparent- allow sunlight to penetrate for photosynthesis

Question 10

what are root hairs?

Answer 10

modified epidermal cells, elongated outgrowths

Question 11

Structure and functions of root hairs? (4 each)

Answer 11

• large amount- increase surface area for max absorption of water and dissolved substances
• elongated- penetrate between soil particles
• no cuticle- allow easy entry of water
• thin cellulose walls- rapid diffusion of water

Question 12

diagram of root hairs? (6)

Answer 12

nucleus
cytoplasm
vacuole with cell sap
tonoplast
cell wall
cell membrane

Question 13

What are Stomata?

Answer 13

structures formed by guard cells(modified epidermal cells)

Question 14

Structure of stomata? (3)

Answer 14

• guard cells contain chloroplast for photosynthesis
• thick inner walls of guard cells, non elastic
• guard cells contain vacuole with cell sap

Question 15

function of stomata? (1)

Answer 15

guard cells open and close stoma to allow for gaseous exchange into and out of the cell

Question 16

Explain Opening of stoma?

Answer 16

sunlight-photosynthesis- lower water potential gradient- water diffuse into guard cells through osmosis- vacuole swell as turgor increase-guard cells swell unevenly due to thick inner walls- guard cells walls apart and pore opens

Question 17

Explain closing of stoma?

Answer 17

no sunlight- no photosynthesis- water potential gradient reverses- vacuole shrinks as turgor decrease- thick guard cells inner walls come together and close pore.

Question 18

diagram of stoma? (7)

Answer 18

epidermal cells
thin outer walls
thick inner walls
chloroplasts
vacuole with cell sap
pore
nucleus

Question 19

What is the most general tissue type in plants?

Answer 19

parenchyma

Question 20

Structure of parenchyma? (5)

Answer 20

thin cell walls
nucleus
large vacuole
intracellular spaces
rounded-elongated

Question 21

Functions of parenchyma? (5)

Answer 21

• storage(starch/oils)
• filling tissue in plant organs
• meristematic function- can further differentiate
• transport gasses and water
• secrete enzymes etc…

Question 22

What are the two type of dead cells and what respective tissue are they?

Answer 22

sclerenchyma- ground tissue

xylem- vascular tissue

Question 23

what tissue is Phloem?

Answer 23

Vascular tissue

Question 24

Structure of collenchyma? (2)

Answer 24

thickened corners

no intracellular spaces

Question 25

function of collenchyma? (1)

Answer 25

to give strength and support to plant

Question 26

Structure of fibers(3) VS sclereids and general (1)

Answer 26

``` general- thick walls fibers - long tapering cells with tapered ends - lignin, pectin, cellulose - no intracellular spaces sclereids- stone cells(cavities)- diff shapes ```

Question 27

Function of Sclerenchyma?(1)

Answer 27

To give mechanical support to plant

Question 28

Structure of xylem vessels(5)?

Answer 28

``` thin cell walls elongated hollow continuous pits(lateral transport) perforated ends ```

Question 29

Structure of xylem tracheids? (4)

Answer 29

thin cell walls elongated pits pointed ends

Question 30

Functions of xylem? (2)

Answer 30

upwards transport of water and dissolved substances from roots to leaves to give strength and support in woody plants (bark)

Question 31

What is the function of phloem? (1)

Answer 31

translocation of dissolved organic food from leaves to rest of plant

Question 32

Structure of phloem sieve tube?(5)

Answer 32

- thin/thick cell walls - elongated - pits and plasmodesmata - sieve plates(transverse perforated) - No nucleus

Question 33

Structure of phloem companion cells?(3)

Answer 33

- thin cell walls - nucleus that controls metabolic activities of both cells - pits and plasmodesmata

Question 34

Adaptations of of xylem to water transport?

Answer 34

Dead and empty no cross walls strong lignified walls to keep open

Question 35

what are trichomes and function?

Answer 35

epidermal outgrowths on stems. protecting them from UV light, insect predation, and excess transpiration