plant organs and transport of materials within plants (week 13)

Question 1

what are the three main organs of a plant and their functions?

Answer 1

roots: anchor the plant and absorb water and minerals
stems: support the plant, raise leaves for sunlight, and transport water, nutrients, and sugars
leaves: carry out photosynthesis to produce food for the plant

Question 2

what is the function of xylem?

Answer 2

transport water and minerals from roots to leaves

Question 3

what is the function of phloem?

Answer 3

transport sugars from leaves to the rest of the plant

Question 3

what is vascular tissue?

Answer 3

tissue (xylem and phloem) that transports water and nutrients

Question 4

what are meristems?

Answer 4

regions of actively dividing cells for growth (e.g., root tips)

Question 5

what are palisade cells?

Answer 5

leaf cells packed with chloroplasts for photosynthesis

Question 6

what is spongy mesophyll?

Answer 6

leaf tissue with air spaces that allow gas exchange

Question 7

what is the main difference between vascular/non-vascular plants?

Answer 7

vascular: have specialised tissues (xylem and phloem) to transport water and nutrients. these allow them to efficiently transport water and nutrients, meaning that they can grow tall
non-vascular: rely on diffusion and osmosis for water and nutrient uptake. this is a less efficient process, therefore they can’t grow as tall

Question 8

what direction does water move in the xylem?

Answer 8

from roots to leaves (one way)

Question 9

what is transpiration?

Answer 9

the loss of water vapour from leaves through stomata

Question 10

what is translocation?

Answer 10

the movement of sugars through the phloem

Question 11

what energy is needed for phloem transport?

Answer 11

ATP (active transport is used to load sugars into phloem)

Question 12

what is a source of translocation?

Answer 12

a region where sugar is made (e.g., leaves)

Question 13

what is guttation?

Answer 13

the loss of water in liquid form from leaf tips, due to root pressure

Question 14

what are the functions of the stem in plants, including support and transport?

Answer 14

• structural support
• hold leaves up to capture sunlight
• transport water, minerals, and sugars between roots and leaves through vascular tissues

Question 15

what part of the leaf carries out photosynthesis and what is its function?

Answer 15

• mesophyll tissue (especially palisade cells)
• contains chloroplasts
• these absorb light to convert carbon dioxide and water into glucose and oxygen

Question 16

what are the stomata? where are they found and how are they controlled in response to the environment?

Answer 16

• small pores, mostly found of the underside of leaves
• allow gas exchange, and control water loss
• they open and close in response to environmental conditions (e.g., light, humidity)
• regulated by guard cells

Question 17

what are the two main transport tissues in vascular plants?

Answer 17

xylem - transports water and minerals from roots to leaves
phloem - transports sugars from leaves to the rest of the plant

Question 18

what drives water movement in xylem, and causes the transpiration steam?

Answer 18

• driven by transpiration, cohesion between water molecules, and adhesion to xylem walls
• creates a transpiration steam

Question 19

what does phloem transport? where does it do after entering the phloem?

Answer 19

• transports sugars (mainly sucrose)
• other organic materials
• to roots, fruits, and growing tissues (sinks)
• where they’re used or stored

Question 20

what are root hairs? where do they form, what is their role in water absorption?

Answer 20

• extensions of root epidermal cells
• form in the zone of differentiation
• increase surface area to effectively absorb water and minerals from the soil

Question 21

what are the two main systems in vascular plants and their functions?

Answer 21

root systems: anchors the plant, absorbs water and nutrients
shoot system: responsible for photosynthesis, reproduction, and transport

Question 22

what are the two types of root systems?

Answer 22

taproot (e.g., carrots) and fibrous roots (e.g., grass)

Question 23

what are the zones of a root and their functions?

Answer 23

root cap: protects the tip and is continuously replaced as cells wear away
meristematic zone: cells are actively dividing
elongation zone: newly formed cells grow in length
zone of differentiation: the cells become specialised (e.g., root hairs, xylem, phloem)

Question 24

what is the function of the epidermis and cuticle in plants?

Answer 24

epidermis: outer layer that protects internal tissues and helps maintain structure cuticle: a waxy layer that covers the epidermis and reduces water loss

Question 25

what do vascular bundles contain in stems?

Answer 25

xylem, phloem, and cambium (a layer of cells that produces new xylem and phloem)

Question 26

what are the cortex and pith in the stem and what are their functions?

Answer 26

cortex: located between the epidermis and vascular bundles, helps with support and storage pith: central part of the stem, composed of soft tissue for storage and support

Question 27

what is the function of the plasmodesmata in plant cells?

Answer 27

microscopic channels through cell walls, connecting plant cells, allowing movement of water, nutrients, and signalling molecules

Question 28

what types of cells are in xylem tissue? what are their characteristics in flowering plants?

Answer 28

xylem contains: - tracheids (long and narrow, found in all vascular plants) - vessels (wide, short, joined end-to-end, main type in flowing plants) both cell types are dead and hollow at maturity for efficient water transport

Question 29

what are sieve cells in phloem and how is sugar transport powered?

Answer 29

sieve cells: long tubular cells with sieve plates for sugar transport, lacking nuclei companion cells: provide energy (ATP) for active transport of sugars into sieve tubes

Question 30

what are monocots and dicots?

Answer 30

two major groups of flowering plants (angiosperms), classified based on differences in their seeds, leaves, stems, roots, and flowers

Question 31

how do monocots and dicots differ in their seeds and leaves?

Answer 31

monocots have one cotyledon (seed leaf), leaves have parallel veins dicots have two cotyledons, leaves have branched (net like) veins

Question 32

how do monocot and dicot stems and roots differ?

Answer 32

monocot stems: have scattered vascular bundles, roots form a fibrous system dicot stems: have vascular bundles in a ring, roots often develop a taproot system

Question 33

how do monocots and dicots differ in their flower parts?

Answer 33

monocot flowers typically have petals in multiples of 3 dicot flowers typically have petals in multiples of 4 or 5

Question 34

what are the two types of buds, what is the difference?

Answer 34

lateral buds (aka axillary buds): produce branches terminal buds (aka apical buds): upward growth

Question 35

what is the difference between transpiration and guttation?

Answer 35

transpiration: the loss of water as WATER VAPOUR from leaf surfaces through stomata, driven by evaporation and occurring mostly during the day guttation: the loss of water IN LIQUID FORM through special pores, usually at night or early morning when soil moisture is high and transpiration is low

Question 36

what is the difference between taproot and fibrous root systems?

Answer 36

- a taproot system has one large, central root that grows deep into the soil, with smaller, lateral roots (e.g., carrots, beetroots) - a fibrous root system consists of many thin roots that spread out near the surface, forming a dense network (e.g., grasses, onions)