specialised cells in plants (tissues)

Question 1

adaptations of palisade mesophyll cell

Answer 1

-absorb light for photosynthesis
-rectangular so can fit closely to form a layer
-thin walled to reduce diffusion distance for CO2
-chloroplasts can move to maximise light absorption

Question 2

adaptations of root hair cells

Answer 2

-long extensions to increase surface area for water and mineral ions uptake
-vacuole containing cell sap which solution can lower water potential
-thin walled so reduce diffusion distance for mineral ions and water

Question 3

adaptations of guard cells

Answer 3

-form openings called stomata for exchange of CO2 and O2
-lose water and change shape to close stomata to prevent water loss
-cell wall thicker on one side so cell doesnt change shape symmetrically

Question 4

epidermal tissue

Answer 4

-flattened sacks
-lack chloroplasts
-form protective covering over leaves
-walls impregnated with waxy substance forming a cuticle to reduce water loss

Question 5

vascular tissue

Answer 5

-concerned with transport
-2 types- phloem and xylem both present in vascular bundle

Question 6

meristematic tissue

Answer 6

-contain stem cells
-from this tissue that all other plant tissue is derived by cell differentiation
-found in root and shoot tips and in cambium of vascular bundles

Question 7

whats the cambium

Answer 7

layer of meristematic tissue in vascular bundles

Question 8

adaptations of meristem cells

Answer 8

-have thin walls containing very little cellulose
-dont have chloroplasts
-dont have a large vacuole
-can divide by mitosis and diffrentiate into other type of cells

Question 9

function of waxy cuticle

Answer 9

-allow water to run off leaf easily preventing damage to lead caused by excess weight

Question 10

function of upper epedermis

Answer 10

-provides protection for chloroplasts in palisade cells from bleaching in bright light

Question 11

palisade cells

Answer 11

-part of the parenchyma tissue making up internal tissue of the lead
-contain large number of chloroplasts adapted for efficient photosynthesis

Question 12

whats the parenchyma tissue

Answer 12

• spongy and palisade mesophyll

Question 13

stem cells in plants

Answer 13

-pluripotent (able to differentiate) cells called meristematic cells which can differentiate into most cell types

Question 14

how do xylem tissue form

Answer 14

-some meristematic cells can differentiate into tubular cells
-cells that die, become hollowed and strengthened w lignin to become waterproof
-joined end to end to form continuous vessels running from roots to leaves

Question 15

organ system in plants

Answer 15

-shoot system (leaves, stem, flowers, fruit)
-root system (roots and tubers underground)

Question 16

what is the phloem composed of

Answer 16

-Collums of sieve tube cells separated by perforated walls by sieve plates