The biology of plants

I. The Plant Cell PS: CO 2 + organelles H2OH2OC 6 H 12 O 6 +O2O2 Light Energy RS:C 6 H 12 O 6 +O2O2 CO 2 +H2OH2O ATP Chloroplast Mitochondrion The products of photosynthesis are the reactants of respiration Glucose

The cell wall 1. Primary cell wall carbohydrate polysaccharide Lignin 2. Secondary cell wall Hardwoods/ softwoods

How a plant grows shoot root Apical meristem Zone of cell division Zone of cell division Zone of elongation Zone of elongation Zone of maturation Zone of maturation

II. Stems Definitions: cells, tissues, organs Shoot system Root system 1. Herbaceous dicot 2. Monocot 3. Woody 3 basic tissue patterns 3 major vegetative organs

herbaceous dicot tissues herbaceous dicot tissues dermal ground (cortex and pith) vascular (xylem and phloem) epidermis cuticle Vascular bundle

2 categories of tissues 2 categories of tissues Meristematic tissues 1. Apical meristem (1 0 growth) 3. Intercalary meristems 2. Lateral meristems (2 0 growth) a. vascular cambium: 2 0 xylem and 2 0 phloem b. cork cambium: cork

Apical Bud

Non-meristematic tissues 1. Simple tissues: one cell type 1 0 cell walls a. parenchyma b. collenchyma fibers sclerids 1 0 and 2 0 cell walls c. sclerenchyma

2. Complex tissues: mixed cell types Non-meristematic tissues Cork = outer bark 2 0 xylem = wood 2 0 phloem = inner bark Vascular cambium: 1 0 xylem 1 0 phloem

Origin of tissues Apical meristem (shoot) parenchyma collenchyma vascular cambium 2 0 xylem 2 0 phloem lots of cells cork cambium outer bark 1 0 xylem 1 0 phloem sclerenchyma

Wood: woody dicots and conifers Development of vascular cambium Cork cambium

Other features of wood Other features of wood 1. sapwood and heartwood 2. vascular rays 3. growth rings

Monocot stems Monocot stems

III. Roots Functions Absorb water and minerals Anchor Monocots versus dicots Herbaceous Root systems 1. fibrous root systems 2. tap root systems Storage Different strategies

Inside roots Inside roots A. Primary tissues 1. epidermis 2. cortex 3. vascular tissues 4. endodermis 5. pericycle B. Secondary tissues

Pericycle Pericycle

IV. Leaves A. Function B. Anatomy of a leaf 1. blades and petioles 2. leaf types CO 2 +H2OH2O C 6 H 12 O 6 + O2O2 light energy chloroplasts/ chlorophyll blade petiole Simple leaf Compound leaf leaflets

C. Leaves of grass Evolutionary pressures: fire herbivory mowing Intercalary meristems

D. Conifer leaves Western white pine Western redcedar Douglas fir epidermis sunken stomata thick mesophyll endodermis hypodermis Waxy cuticle

Inside leaves A. Cellular organization 1. epidermis 2. mesophyll: two parts a- palisade cells b- spongy cells 3. veins: phloem and xylem B. Water loss- cuticles cuticle

Stomata

Photosynthesis I. Preview of photosynthesis II. Photosynthetic reactions III. Light dependent reactions IV. Light independent reactions V. Summary of events and importance of photosynthesis 6CO 2 +6H 2 OC 6 H 12 O 6 + 6O 2 Light energy

Capturing of light: chlorophyll 2H 2 O 4H + + 4e - + O 2 Production of ATP Photophosphorylation ATP synthase Light Dependent Reactions

Light independent reactions Rubisco Glucose CO 2 Fixation

C3, C4, and CAM plants C3 C4 CAM

primary producers Summary of events and importance of photosynthesis PS: CO 2 + H 2 O C 6 H 12 O 6 + O 2 Light Energy RS: C 6 H 12 O 6 + O 2 CO 2 + H 2 O ATP

Plant reproduction I. Flowers A. Pollen grains and ovules B. Reproduction in general C. Flower parts D. Flower characteristics II. Fertilization A. Pollination B. Double fertilization III. Seeds and fruits A. Anatomy of a seed B. Seed dispersal C. Fruit formation D. Fruit types

I. Flowers A. Pollen grains and ovules B. Reproduction in general 7 cells, 8 nucleiovary ovules haploid (1n) versus diploid (2n) egg central cell

C. Flower parts (carpel) (1n) (2n) sepals/calyx /corolla peduncle

II. Fertilization A.Pollination 1. Definition 2. Barriers to self pollination 3. Attraction and rewards Barriers to self pollination time of maturation genetic differences nectar guides mimic high

A. Pollination 4. types animal self buzz wind Out crossing In breeding

B. Double fertilization pollen pollen tube endosperm embryo ovule

I. Seed germination A. Seed dormancy B. Stages in germination 1. imbibition 2. break down of starch 3. radicle, plummule, cotyledons C. Other germination requirements fire acid cold Three basic conditions 1. proper temperature 2. proper moisture 3. aeration

D. Early development radicle root apex shoot apex cotyledons

III. Seeds and fruits A. Anatomy of a seed Monocots versus dicots micropyle hilum

B. Seed dispersal

C. Fruit formation exocarp mesocarp endocarp pericarp

Fruit typeOrigin Simple Single ovary 1. berry Examples Other Many seeds Fleshy endo 2. drupe One seed Stony endo 3. pome Many seeds Papery endo D. Edible fruit types a. hesperidium Juice sacs Leathery exo b. pepo Many seeds Inseparable exo Aggregate Many ovaries Same flower Many fused fruits Multiple Many ovaries Many flowers

The end