2.6.7 plant tissues & organs

Question 1

meristem

Answer 1

area of unspecialised cells within a plant that can divide & differentiate into other cell types

Question 2

organ

Answer 2

collection of tissues working together to perform a function/related functions

Question 3

phloem

Answer 3

tissue that carriers products of photosynthesis, in solution, within plants

Question 4

xylem

Answer 4

tissue that carries water/mineral ions from roots to all parts of plant

Question 5

properties of epidermal tissue

Answer 5

• flattened cells that (apart from guard cells) lack chloroplasts & form protective covering over leaves, stems & roots
• some epidermal cells have walls impregnated with waxy substance - forming a cuticle (esp. important for plants in dry areas)

Question 6

2 types of vascular tissue

Answer 6

• xylem
• phloem

Question 7

what do xylem vessels carry

Answer 7

water/minerals from roots to all parts of plant

Question 8

what do phloem vessels carry

Answer 8

phloem sieve tubes transport products of photosynthesis (mainly sucrose sugar), in a solution, from leaves to parts of the plant that don’t photosynthesise eg. roots, flowers & growing shoots

Question 9

what does meristematic tissue contain

Answer 9

stem cells

Question 10

where’s meristematic tissue found

Answer 10

• all root/shoot tips
• in cambium of vascular bundles

Question 11

properties of the cells in meristems

Answer 11

• thin walls containing little sucrose
• no chloroplasts
• don’t have a large vacuole
• can divide by mitosis & differentiate into other cell types

Question 12

some cambium cells differentiate into xylem vessels:

Answer 12

• lignin is deposited into cell walls (reinforce/waterproof) BUT kills cells
• ends of cells break down = xylem forms continuous columns with wide lumens to carry water/dissolved minerals

Question 13

some cambium cells differentiate into phloem sieve tubes/companion cells:

Answer 13

• sieve tubes lose most of organelles & sieve plates develop between
• companion cells retain their organelles & continue metabolic functions to provide ATP for active loading of sugars into sieve tubes

Question 14

name the 4 diff. plant organs

Answer 14

• leaf
• root
• stem
• flower

Question 15

function of leaf

Answer 15

• photosynthesis

Question 16

function of root

Answer 16

• anchorage in soil
• absorption of mineral ions/water
• storage (eg. carrot & parsnip roots store carbohydrates)

Question 17

function of stem

Answer 17

• support
• holds leaves up = exposed to more sunlight
• transport water/minerals
• transport products of photosynthesis
• storage of products from photosynthesis (eg. potato tubers store starch)

Question 18

function of flower

Answer 18

sexual reproduction