Chapter 23: Structure of The Flowering Plant

Functions of Root System

Functions of Root System

anchor plant into ground, absorb water and minerals, transport absorbed minerals to shoot, storage of food

Types of Root

tap root, fibrous root, adventitious root

Radicle

young root

Tap Root

one main long root that comes from the radicle, present in dicots

Plants with Tap Roots

dandelion, carrot

Fibrous Root

formed when radicle dies and leaves equal sized roots coming out of the stem, present in monocots

Plants with Fibrous Roots

daffodil, grass

Adventitious Root

these do not grow from the radicle, and are found in odd places

Examples of Adventitious Roots

ivy, strawberry plant

Root Zones

zone of protection, meristematic zone, zone of elongation, zone of differentiation

Zone of Protection

root cap protects the meristem as it pushes through soil

Meristematic Zone

region of active cell production where mitosis occurs

Apical Meristems

found at root and shoot tips, responsible for lengething roots and shoots

Lateral Meristems

found at side of plants, responsible for the secondary growth of stems and roots

Zone of Elongation

region of the root or shoot where cells elongate due to newly formed cells absorbing water and plant regulators, contributing to the growth of the plant's length

Zone of Differentiation

the region of the root or shoot where cells undergo specialization into various cell types, contributing to the formation of different tissues in the plant

The Shoot System

the part of the flowering plant that includes stems, leaves, and flowers, responsible for photosynthesis, support, reproduction, and transport of nutrients.

Twig Diagram

terminal bud, lenticel, lateral bud, leaf scar, current years wood, girdle scar, dormant wood bud, last years wood, node, internode

Leaves

the main sites of photosynthesis and transpiration, also known as lamina

Petiole

the stalk that attaches the leaf blade to the stem, supporting the leaf and facilitating transport of nutrients and water

Sessile

a type of leaf that is directly attached to the stem without a petiole, allowing for a more compact structure

Parallel Venetion

veins parallel to eachother, found in monocots

Net Vention

veins are branched, found in dicots

Plant Tissue

meristematic, dermal, ground, vascular

Meristematic Tissue

simple cells with no vacuoles, responsible for mitosis

Dermal Tissue

protective cover on stem, leaves and root, stops entry of pathogenic organisms, designed to absorb water and minerals at root tips

Adaptation of Dermal Cells

waxy layer to prevent water loss

Ground Tissue

fills interior of the plant body, stores food and provides strength to the plant

Vascular Tissue

transport substances wihtin the plant, two types are xylem and phloem

Xylem

transports water and mineral salts from the roots to the leaves, provide mechanical support, said to be dead

Xylem and Phloem Location

located in roots, stem, leaves and flowers

Xylem Types

xylem tracheids, xylem vessels

Xylem Tracheids

long cells tapered at both ends, contains pits, only found in conifers, contains lignin

Xylem Vessels

form when numerous cells join end to end, wider than tracheids and are stacked together, forms a continuous conducting tube, contains pits, contains lignin

Use of Pits in Xylem

allows water and minerals to move sideways from cell to cell

Use of Lignin in Xylem

structural polysaccharide used to strengthen walls

Phloem

transports food made in the leaves, companion cells within controls sieve tube element, are elongated cylindrical cells stacked end to end.

Sieve Plates

allow cytoplasm to pass from cell to cell, each one has a companion cell connected by cytoplasmic connections

Monocotyledon

one cotyledon, vascular bundles are scattered, parallel veins, flowers have petals in multiple of 3

Dicotyledon

two cotyledons, vascular bundles in ring shape, dendritic veins, flowers hace petals in multiples of 4/5

Tropism

growth response of a plant to a stimulus

Phototropism

growth of a plant in response to light

Function of Phototropism

allows plant to recieve maximum amount of light for photosynthesis

Geotropism

growth in response to gravity

Function of Geotropism

allows root to get the water and nutrients it needs from the soil, and raises the leaves into light for photosynthesis

Thigmotropism

growth of a plant in response to contact

Function of Thigmotropism

gives support to the plant

Hydrotropism

growth of a plant in response to water

Function of Hydrotropism

allows plant to get maximum water it can get

Chemotropism

growth of a plant in response to chemicals

Function of Chemotropism

allows plants to move towards useful minerals, and away from harmful chemicals

Plant Growth Regulators

chemicals that interact with one another to control a particular development or response

Location of Plant Growth Regulators

produced in meristems and transported through vascular systems

Examples of Plant Growth Regulators

auxins, gibberellins, cytokinins, abscisic acid, ethene

Auxin

promote cell enlargement and growth, involved in phototropism and apical dominance, can be used to kill weeds

Gibberellin

causes stem lengthening, mobilise the stored food in germinating seeds, break dormancy in buds and seeds in spring

Cytokinins

stimulate cell division and trigger leaf growth in spring

Abscisic Acid

triggers bud and seed dormancy in autumn and inhibits cell growth

Ethene

promotes ripening of fruit and the fall of leaves, flowers and fruits

Structure of the Flower

sepal, ovule, ovary, petal, style, filament, stigma, anther

Stamen

male part of plant, filament, anther

Carpel

female part of plant, stigma, style, ovary