plant organs term 3

Question 1

what are the plant organs

Answer 1

roots - anchor plants and absorb water minerals
stems - support leaves for photosynthesis
leaves - for photosynthesis, transpiration and gaseous exchange
flowers - for reproductiom through pollination
fruit - for reproduction through seed dispersal

Question 2

what are the two types of leaves

Answer 2

isobilateral leaves - both surfaces look the same
dorsiventral leaves - both surfaces are different

Question 3

Seed plants are divided into two main groups

Answer 3

gymnosperms
angiosperms

Question 4

gymnosperms

Answer 4

gymnosperms
Non-flowering seed plants
e.g. pine trees, yellowwood trees and cycads

Question 5

angiosperms

Answer 5

flowering plants
e.g. sunflowers, corn and orange trees

Question 6

Angiosperms are divided into two main groups

Answer 6

dicotyledons (dicots)
monocotyledons (monocots)

Question 7

Main support tissues in plants

Answer 7

collenchyma
sclerenchyma
xylem

Question 8

Main transport tissues in plants

Answer 8

xylem
phloem

Question 9

Xylem tissue is made up of…

Answer 9

xylem vessels
xylem tracheids
xylem sclerenchyma fibres
xylem parenchyma

Question 10

Xylem vessel features…

Answer 10

primary cell wall made of cellulose
dead cells, no cytoplasm
long, cylindrical tubes
ends of tubes (cross walls) have perforated plates
thick secondary walls of lignin
lignin either annular, spiral, scalariform or pitted

Question 11

Xylem tracheid features…

Answer 11

similar to tracheids
cell ends tapered (pointed)
narrow diameter

Question 12

Xylem suited for support because…

Answer 12

thick secondary walls of lignin
round shape in cross section
strong to resist shearing forces (forces acting at different angles to the cell)

Question 13

Xylem suited for transport because…

Answer 13

cross walls perforated
cells are dead and hollow
pits and gaps in thickening allow water to move sideways between cells

Question 14

Xylem transports…

Answer 14

water
dissolved mineral salts

Question 15

Phloem transports…

Answer 15

manufactured organic foods
e.g. glucose and sucrose

Question 16

Phloem tissue is made up of…

Answer 16

sieve tubes
companion cells
phloem schlerenchyma fibres
phloem parenchyma

Question 17

Sieve tube features…

Answer 17

Primary cell wall of cellulose
no secondary thickening
living cells with no nucleus or cytoplasm
long, tube like
sieve plates at ends with holes
Large vacuoles (cell body) with cytoplasmic threads

Question 18

Companion cell features…

Answer 18

Living cells
dense cytoplasm with a nucleus
found next to sieve tubes to manage their metabolism

Question 19

Functions of the root system in plants…

Answer 19

anchorage
support
storage
nutrient uptake
transport
reproduction

Question 20

Region of root where xylem and phloem are found…

Answer 20

the stele

Question 21

Support tissues in a root…

Answer 21

collenchyma
schlerenchyma
xylem

Question 22

Transport tissues in a root…

Answer 22

Xylem
Phloem

Question 23

Describe the outermost layer of a root…

Answer 23

Epidermis tissue
No cuticle to be able to absorb water
Root hairs may be present to increase surface area

Question 24

The two main root regions of a dicot (cross section)

Answer 24

Cortex (outer)
Stele (inner)

Question 25

Describe the cortex in a dicot…

Answer 25

From outside inwards: (Epidermis) Exodermis central cortex endodermis (innermost layer)

Question 26

Describe the endodermis…

Answer 26

Single layer of parenchyma cells Wall thickening called Casparian band (helps control water movement)

Question 27

Describe the stele…

Answer 27

Pericycle tissue - produces secondary roots Conducting tissue - xylem and phloem

Question 28

regulation of gas movement by the stomata

Answer 28

stomata opens durinfg the day photosynthesis occurs in the guard cell and water moves in by endosmosis guard cells become turgid and pores open.

Question 29

two types of root systems

Answer 29

tap root fibrous root

Question 30

function of stem in plants

Answer 30

transport support and position

Question 31

what is the secondary meristematic tissue found in roots and stems of plants

Answer 31

cambium

Question 32

define transpiration

Answer 32

loss of water vapour from the aerial parts of the plant

Question 33

what are the two types of transpiration

Answer 33

stomatal transpiration- loss of water vapour through stomata cutiular transpiration- loss of water through the cuticles

Question 34

what is wilting

Answer 34

plant cells become soft and tear away from the cell wall

Question 35

what is guttation

Answer 35

happens when more water is absorbed into the plant from the roots than the transpiration rate and water evaporation from the leaves

Question 36

what is root pressure

Answer 36

water continuously pushed up the xylem

Question 37

what are the benefits of transpiration

Answer 37

cooling the plant: loss of water vapour cools down the plant transpirational pull: water and mineral salts continuously brought up from the stem plant structure: helps maintain turgidity

Question 38

factors that affect the rate of transpiration

Answer 38

temperature light intensity wind humidity

Question 39

what is the device that measures the rate of transpiration

Answer 39

the potometer

Question 40

what is translocation

Answer 40

transport of food from the source to other parts of the plant