LEAVES23.4

Function Photosynthesis Transpiration – pulling

water up from the roots and out the leaves

Structure

Epidermis Upper – covered by cuticle Lower – contains stoma

with guard cells

Cont.

Palisade layer – many chloroplasts

Mesophyll – many air spaces

Vascular bundle – “veins”

VEIN

PalisadeLayer

MesophyllStomata

Epidermis with cuticle

External Structures Petiole – structure that

attached leaf to stem Blade – thin, flat area of leaf;

different sizes, shapes & arrangement

Mid rib – main vein Leaf margin – edge of leaf

Venation in Monocots and Dicots

Monocots – parallel leaf venation

Dicots – netted venation

Pop Quiz

Flowers, Fruits & SeedsCh. 24

Angiosperms

reproduce using flowers.

Flowering Plants have:Monocot Dicot

FlowersMultiples of 3 Multiples of 4 or 5

1

23

4

5

6

23 4

5

6

7

18

6

Flowers Composed of modified leaves

Sepals – usually green; enclose bud Petals – brightly colored; just inside sepals Stamen – male reproductive organ

Filament - stalkAnther – produces pollen (male gamete)

Carpel (pistil) – female reproductive organ Stigma- sticky; pollen attaches hereStyle – narrow stalkOvary – contains ovules

Anther

filament

Parts of a Typical Flower

StamenMale partof flower

AntherFilament

Parts of a Typical Flower

PistilFemale part

of flower(Sounds like “Pigtail”)

Stigma

Style

Ovary

Plant ReproductionPlants can reproduce asexually by

vegetative propagation.

Stems

PlantletsRoots

Stems, plantlets and roots can become a new plant.

Plant ReproductionPlants can reproduce asexually by

plant propagation.

CuttingsGrafting & Budding

A “cut” from a plant cangrow roots when put in soil. Two plants are attached

to form one plant.

Angiosperm Life Cycle Pollination – transfer of pollen from anther

to stigma of carpel Often dependent on pollinators Pollen grows a tube through which

sperm nuclei travel Fertilization –

sperm nuclei fuse with ovule inside produce a seed Ovary ripens into a fruit

Fruits – ripened ovary ; type determined by structure of ovary and ovules Dry

Nuts Fleshy

Drupes - apple Pomes - peach Berries Hesperidium - orange Pepo - cucumber Aggregate - raspberry

Seed Dispersal Animal Wind Water

Seed Germination Timing controlled by climate (moisture,

temperature, etc.) Endosperm (food source) swells with

moisture and cracks open seed coat Root emerges first Cotyledons emerge second

Monocot – one seed leaf Dicot – two seed leaves

Plant Growth Controlled by hormones (auxins) Cause “tropisms”

Gravitropism Thigmotropism phototropism