plant transport systems Flashcards
(86 cards)
1
Q
cells in unicellular organisms
A
carry out all the functions of the organism
2
Q
cells in multicellular organisms
A
cells work tgt but with different jobs. they are specialised.
3
Q
nerve cells
A
transmit impulses
4
Q
red blood cells
A
carry nutrients n gas throughout the body
5
Q
pancreatic cells
A
produce insulin
6
Q
muscle cells
A
contract n relax to move parts of the body
7
Q
how does multicellular life start?
A
the fusion of specialised productive cells called gametes (ovum n sperm)
8
Q
cell differentiation
A
process where unspecialised stem cells become specialised
9
Q
specialised cells
A
begin to take on characteristic structures n functions that r needed in the adult organism
10
Q
levels of organisation (low-high)
A
cells, tissues, organs, organ systems
11
Q
cells in the levels of organisation
A
basic units
eg. rbc, nerve, pancreatic, skin
12
Q
tissues
A
group of cells that perform a particular function
eg. muscle, epithelial
13
Q
organs
A
group of tissues that work tgt
eg. heart, liver, stomach
14
Q
organ systems
A
group of organs that work tgt to perform a specific function
eg. digestive, respiratory
15
Q
where do specialised cells in plants come from?
A
meristem tissue
16
Q
apical meristem tissue
A
give rise to primary growth (lengthening), produces new branching shoots, leaves n flowers, occurs at the tips of the roots and shoots of the plant
16
Q
lateral meristem tissue
A
secondary growth (widening), produces bark on trees, occurs at the cambium
17
Q
what leads to plant growth?
A
cell enlargement n repeated cell division (mitosis n cytokinesis)
18
Q
what does the differentation of the diving meristem give rise to?
A
variety of stem tissues n structures - including leaves n flowers
19
Q
root hair cells
A
take up water n nutrients
20
Q
mesophyll cells
A
photosynthesis
21
Q
epidermal cells
A
protection
22
Q
companion n sieve cells
A
transport
23
Q
stomata
A
gas exchange
24
complex plants have tissue, organ and system structures.
true
25
vascular plants
complex land plants w/ specialised vascular tissue that conducts water, mineral ions, n sugars
26
what do vascular n structural tissues allow these plants to do?
grow muhc larger than non-vascular plants like algae n moss
27
root system
supports the structure of the plant n absorbs nutrients n water from the soil
28
shoot system
includes vegetive parts - leaves n stems, reproductive parts - flowers n fruits
29
# plant organs
reproductive structures
* function to make more plants
* include flowers, fruits, cones, seeds
30
# plant organs
leaves
primary site of photosynthesis
31
# plant organs
stems
* support n elevate the leaves
* transport water n nutrients between roots n shoots
* store water n nutrients
32
# plant organs
roots
* anchor the plant
* absorb minerals n water
* store nutrients
33
function of roots
water n mineral ions (nitrogen, potassium, etc.) from the soil n exchange gases
34
how do roots exchange gases?
in the air spaces between soil particles. the oxygen diffuses into the moisture film surrounding root hairs n then the roots
35
what happens to gas exchange if indoor plants r overwatered?
in waterlogged soil the air spaces r filled with water. water contains less oxygen, reducing the plant's access to oxygen. indoor plants commonly die due to a lack of oxygen for cellular respiration.
36
function of leaves
gather carbon dioxide, water n sunlight to allow photosynthesis to occur
37
three layers of tissue in leaves
upper epidermis, mesophyll, lower epidermis
38
what does the epidermis do?
secretes a waerproof waxy layer - the cuticle, which protect the leaf from water loss
39
feature of upper epidermis cells
transparent n do not have chloroplasts
40
in which cells do most photosynthesis occur?
palisade mesophyll cells
41
2 energy transforming reactions in plants
photosynthesis n cellular respiration
42
43
photosynthesis occurs primarily in the chloroplasts in stems.
false
| in leaves
44
what regulates gas exchange in leaves?
stomata, through diffusion
45
how do guard cells control the opening n closing of the stomata?
the stomata is a pore created by 2 guard cells. when water enters guard cells, the internal water pressure (turgor) increases and the pore closes. when water leaves guard cells, the pore opens.
46
where r stomata found?
typically on the lower epidermis of leaves, away from the sun to reduce water loss
47
when do stomata open n close?
open during the day to allow gas exchange to occur, closed at night when there is no light for photosynthesis
48
stomata in plants adapted to dry conditions
in sunken pits to reduce air flow across the stomata n water loss
49
stomata in water lilies that float on water
found on the upper surface
50
mesophyte definition
plants that need moderate amounts of water
| typically more stomata in lower epidermis
51
co2 in mesophytes
diffuses from the air through the stomata n into the air spaces of the spongy mesophyll then up to the palisade layer
52
water in mesophytes
diffuses from the xylem into the air spaces n up to the palisade layer then out through the stomata
53
features of xerophytes
* adapted to dry conditions
* thicker cuticle
* stomata on the lower epidermis in hair-lined pits, moist air is trapped here to reduce evaporation rate
54
hydrophytes definition
grown in or on water, aquatic plants
| more stomata r present on the upper epidermis
55
features of hydrophytes
* ensure effective light collection
* large air spaces -> buoyant n close to the surface so that co2 can diffuse in from the air
56
transport in vascular plants
* water n minerals r absorbed through the roots
* gases r transported through roots n the stomata in leaves
* photosynthesis occurs in leaves n stems to produce energy
* transpiration (loss of water) occurs through the leaves
57
how is vascular tissue visible?
the veins in grasses n leaves, stringy parts of celery
58
# vascular tissue
xylem
transport of water n dissolved minerals up from the roots to the rest of the plant
59
# vascular tissue
phloem
main transport of sugars n amino acids from leaves to where its needed
| leaves - site of photosynthesis
60
arrangement of xylem and phloem
* xylem - cross or star shaped in centre of root with phloem surrounding
* xylem n phloem in stems n leaves are arranged in bundles
61
what does xylem consist of?
* mainly xylem vessels n tracheids
* supporting fibres n parenchyma
| parenchyma - soft cellular tissue
62
describe 3 features of xylem vessels
* dead cells joined end to end
* cell walls strengthened by lignin
* cytoplasm n cell membrane disintegrates as the cell matures
63
describe 2 features of tracheids
* dead single cells with tapered ends
* walls of cells have pits enabling (horizontal) transfer of water between cells
64
how does water transport through xylem?
* perforation plates or a complete opening
* through a continuous tube
65
what starch ends up being sent through the phloem?
remainder of starch; the rest is either converted to starch to be stored, or used immediately for photosynthesis
66
what does phloem consist of? describe what each of their functions are.
sieve tube cells: move sugars throughout the phloem
companion cells: actively move sugars n amino acids into the sieve tube
67
describe the movement of sugars
bi-directional, up and down
68
transpiration
movement of water trough a plant from absorption of water (roots) to evaporation (leaves)
| xylem
69
why is 99% of water used for transpiration in a plant?
* cools the plant
* transports minerals
* provides water for photosynthesis
70
2 processes that work tgt to pull water up through the xylem
negative pressure, cohesion/adhesion
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negative pressure
movement of water through xylem is passive, occurs due to energy from the sun evaporating water, creating a negative pressure that draws water up
72
cohesion/adhesion
* cohesion - water to water: as water is a polar molecule, the positive H side is attracted to the negative O2 side
* adhesion - water to other: water interacts with hydrophilic cell walls
73
list 3 factors that increase the rate of transpiration
* light: stomata open wider to increase the uptake of co2 n rate of p.s
* heat from sun: evaporation n diffusion r faster at higher temps
* air flow/wind: water vapour is removed by air flow, increasing rate of evaporation
74
list 1 factor that lowers the rate of transpiration
humidity: evaporation of water from the leaf slows, as the leaf is surrounded by moist air
75
translocation
movement of organic solutes from source (leaves) to sinks (roots, stems, flowers, fruits)
| organic solutes - sugars, hormones, proteins
76
describe the fluid where translocation occurs.
* phloem sap: 90% sucrose sugar
* flows in both directions, but due to low turgor pressure in roots and high in leaves/shoots, hence bulk movement from source to sink
76
describe the general process of translocation
1. sucrose from leaf actively moves into companion cells then into sieve cells
2. increases solute concentration in sieve n sieve tube cells, therefore take up water through osmosis
3. water uptake creates hydrostatic pressure, positive pressure gradient forces sap to move along the sieve tube
4. root cells, shoots, fruits actively remove sugars
77
describe two pathways water can enter from the roots.
* cytoplasmic/cell to cell pathway: mostly nutrient ions/minerals (some water)
* substances enter a root hair cell through the plasma membrane, then moving cell to cell
* cell wall pathway: extracellular, mostly water (some nutrients)
78
79
# root absorption
active transport in transporting water intro cells
selective mineral uptake thorugh protein pumps, concentration of ions in root is well above soil concentration
80
# root aborption
osmosis in transporting water into cells
high ion concentration creates osmotic gradient, pulls water into root
81
# root aborption
what can diffusion transport from the roots?
mineral ions (potassium, phosphate)
82
Casparian strip
waterproof layer of cells, where water movement is forced through cytoplasmic pathway, maintains osmotic pressure
83
definition of guttation
loss of liquid water from leaves through pores at the end of leaf veins
84
3 features of guttation
* usually occurs at night, moist air
* consequence of root pressure
* assists plants in humid conditions to cycle water up thorugh plant and transport fresh water n nutrients
| humid conditions - lower transpiration rates
