Plants

SC.912.L.14.7

Plant Overview

More than 400,000 different species of plants have been identified (and more are out there!)

Plants evolved from an organism much like the multicellular ALGAE we see today

What are some unique feature to a plant cell??? Cell wall, central vacuole, chloroplasts

How do plants obtain energy? Photosynthesis (to make their food) and then cellular respiration (to

actually get ATP to do all those cool things living organisms do….) Grow and develop Reproduce Maintain Homeostasis Evolve Obtain and use resources

Plant characteristics

Domain Eukarya

Kingdom Plantae

Evolved from unicellular algae

Multicellular Many cells organized into tissues

organized into functioning organs to make a function organism

Autotrophic They can make their own food…

GLUCOSE!!! Use Photosynthesis to do so…

Two Major Groups of PlantsVASCULAR Tissue is tissue that transports water and

nutrients in an organism

Plants

Bryophytes(non-vascular)

Lack specialized tissue for H2O

transport

Tracheophytes(vascular)

Have specialized tissue that transports H2O and nutrients

Seedless plants

Non-flowering

seed plants

Flowering seed

plants

BryophytesNon-vascular

No specialized tissue to carry H2O

Absorb nutrients directly from surroundings osmosis

Examples Mosses Liverworts Hornworts

Tracheophytes Vascular system

Transport system between ORGANS of plant roots, stems and leaves Plants have different structure and

arrangement of these organs to adapt to their environment

Transport water and nutrients all over=LARGE sizes

Examples: Seedless plants…

FERNS GYMNOSPERMS: Non-flowering

seeded plants PINE TREES

ANGIOSPERMS: Flowering seeded plants DAISYS

Vascular Tissue

VEINS of the plant (similar to our blood vessels)

can move fluids through the body of a plant, even against the force of gravity

XYLEM Carries water from the roots

to the stem and leaves

PHOLEM Transports solutions of

nutrients and carbohydrates made by photosynthesis in the leaves to all the other parts of the plant

Major Organs of the Plants

Roots Anchor and support plant Absorb water and dissolved nutrients from the soil Store food and water

Stem Transport materials between plants roots and its leaves and

flowers Support leaves and flowers Some store food and water

Leaves Main organs that carry out photosynthesis Many adaptations (size, shape, structure) to help plant

survive Needles Flowers

Roots2 types

Taproots Single, large root that grows

deep into soil Smaller roots branch off main

root Good at storing food and water DICOT plants have taproots

Examples: Carrots and beets Desert plants have very long

taproots…why do you think?

Fibrous roots Does NOT have single main root Many small, shallow roots

branching from base of plant MONOCOT plants have fibrous

roots Examples: Grasses

Stems Connect roots to leaves and

flowers

TRANSPORT

Defense against predators and disease

Storage of food and water POTATOES: modified stems that

store lots of food in form of starch

• WOODY plants (trunk is the stem) Trees and shrubs have HARD

Stems Larger and long life spans

• HERBACEOUS plants Plants with green, flexible stems Smaller, and shorter life spans

Leaves Location of Photosynthesis

Three major structures of leaf Petiole- tube like structure that

attaches leaf to stem Blade- broad, flat part of leaf Veins- tube-like structures that

transport water to leave

Stomata Small, pore-like openings on the

underside of leaves Site of TRANSPIRATION

water Site of Gas exchange (respiration)

Carbon dioxide and oxygen Guard cells

Tiny cells, that control the opening and closing of the stomata

Adaptations

Leaf AdaptationsAdaptations

Pine Needles and Cacti: needle shaped leaves or microscopic leaves b/c they need to prevent water loss

Rainforest plants: broad, flat leaves b/c they need to catch as much light as possible in shade

Flowers: modified leaves for sexual reproduction

Major Plant Tissues Dermal tissue

Outer covering of leaves made of epidermal cells Waxy “cuticle” and fuzzy appearance of leaves (from tiny projections called

trichomes) On roots, this tissue is the roots hairs (increase surface area to increase water

absorption)

Vascular tissue Transport (xylem and phloem)

Ground tissue Tissue made of the cells that lie between dermal and vascular tissue Made of cells with many central vacuoles In leaves, this tissue is made of cells with many chloroplasts

Meristematic tissue Clusters of tissue that is responsible for continuing growth throughout a plants

lifetime “indeterminate Growth” Growth that produces new cells at the tips of a plants roots and stems throughout a

plant’s lifetime Made of “undifferentiated” cells…a plants STEM CELLS

Only part of the plant that produces new cells by mitosis

Cambium Plants grow tall from APICAL

MERISTEMS

How do they get wider???

Secondary Growth Method of growth where stem

increase in WIDTH Conifers and Dicots

Secondary growth takes place in: Vascular Cambium lateral

meristematic tissue that produces vascular tissue and increases thickness of stem (makes wood of a tree)

Cork Cambium lateral meristematic tissue that produces outer covering of stems (makes bark of a tree)

Plants: Flowers, Fruits and Cones

I’m Sexy and You Know it!

Most EVOLVED plants

Flowering Plants Very Attractive! Smell good Look pretty There is a reason they are

used in courtship

Reproduce sexually

Contain both MALE and FEMALE reproductive parts

Angiosperms Seed plant that produces a

seed that is enclosed by a fruit

Fruit develops inside the flower

Surround by lots of yummy Glucose

Flowers are Modified leaves Reproductive Organ of the

Angiosperm Attractive color and smells to

attract birds and bees to help them cross-pollinate = GENETIC DIEVRSITY!!!

Flowers

Flower Anatomy

Pistil (female parts) Stigma Style (with

pollen tube) Ovary Ovule

Stamen (male parts) Anthers (pollen) Filaments

Let’s Practice…

POLLEN!!!

Pollen on the Stig

ma…Reproduction in Actio

ns!

Seeds

Reproductive structure of plant that contains a plant embryo Part of embryo will develop into stem, leaves and

roots of new plant In flowering plants, seed also contains food

(glucose=sugar) and protective coat (ie. banana peel)

Seed of Angiosperm may have one or two baby leaves (called cotyledons) 1 cotyledon= monocot (grasses/grains) 2 cotyledons= dicot (beans)

Fruits

• Pollination transfer of pollen from the stamen to the pistil

• When pollen gets into style, Fertilization of the eggs in the ovary of the flower occur

• After fertilization, more seeds develop in ovary

• Ovary develops into a protective FRUIT providing developing seeds with lots of yummy GLUCOSE!

Angiosperms are classified in

Two CategoriesMonocots………………..……Dicots

Taproot

Fibrous root

Cones UNLIKE seeds of flowering plants

NO protective coating of the embryo

More sexiness AKA reproduction!

Gymnosperms Conifers (Pine trees) do NOT have

flowers but they do have CONES

Male Pollen cones…pollen carried by

wind

Female Ovules under scales

All These Sexy Plants!

Time to Review

Plant structure and processes

1. Jenny is comparing the reproductive structures of different species in the plant kingdom. Which structures would most useful for determining angiosperms from gymnosperms?

A. Fruits and cones

B. Anthers and pistils

C. Xylem and phloem

D. Needles and pollen

Plant structure and processes

2. For which important process in the plant physiology do openings on the undersides of leaves need to be open?

A. Photosynthesis

B. Phototropism

C. Reproduction

D. Respiration

Plant structure and processes

3. The leaf cells of green plants usually contain thylakoids. The root cells of green plants do not usually contain these structures, or contain fewer of them. Which statement best explains why?

A. Root cells eject organelles to make space for water and nutrients to pass through the roots.

B. Roots cells are simpler and do not need energy to perform their specialized functions.

C. Leaf cells are large enough to contain thylakoids, but the root cells are not.

D. Leaf cells are the primary site for light-dependent chemical reactions.

Plant structure and processes

4. Which of the following events indicates that a plant’s reproductive system has successfully carried out its function?

A. A seed forms.

B. A flower opens.

C. A root system expands.

D. A sprout grows to maturity.

Plant structure and processes

5. Which type of dermal cell has more chloroplasts than other dermal cells because it has greater energy needs?

A. Cuticle

B. Guard cells

C. Lower epidermal cells

D. Upper epidermal cells

Plant structure and processes

6. What type of cell is indicated by label B?

A. An epidermal cell

B. A guard cell

C. A stomata

D. A nucleus

A

C

B

Plant structure and processes

7.What is one of the main advantages of asexual reproduction?

A. It occurs more slowly than sexual reproduction.

B. There is a smaller chance of mutation.

C. The offspring varies from the parent.

D. It creates more genetic variety.

Plant structure and processes

8.Which fact about the apical meristem makes this a good suggestion? (NNED DIAGRAM)

A. Enzymes in the apical meristem carry out DNA replication.

B. Photosynthesis takes place in the chloroplasts of green plant cells.

C. Auxins produced in the meristem inhibit the growth of lateral buds.

D. The apical meristem uses triphosphate (ATP) as its energy source.

ANSWERS

1. A

2. D

3. D

4. A

5. B

6. C

7. B