Plant Kingdom

Plant KingdomMrs. Wetzel

Biology

What is a plant• Eukaryotic• Multicellular• Mostly Autotrophs• Cell walls made of cellulose

In order to survive• All plants Need:

– Sunlight– Water– Gas exchange– Movement of water and nutrients

Evolution• Most plants started out in the

water• They were able to survive on land

because of– Adaptations to retain moisture

– Cuticle– Seeds

Plant classification• Botanists divide plants into four

groups based on three features:– 1. Vascular tissue– 2. Seeds– 3. Flowers

Plant Kingdom:• Bryophytes= mosses & their

relatives• Vascular Non seed= Ferns & their

relatives• Gymnosperms• Angiosperms

Plant Diversity• Bryophytes- mosses, liverworts,

hornworts– Need water for their reproductive

cycle– Do not have vascular tissue=

must remain short rely on osmosis

Bryophytes: mosses/liverworts/hornworts

Bryophytes: Ecology• Peat Moss- used in gardening,

improves the soils ability to retain water

Biodiversity/ Symbiosis

Plant Kingdom:• Bryophytes- Mosses• Non- Seed Vascular – ferns• Gymnosperms- cone bearing• Angiosperms- seed bearing

Non-Seed Vascular PlantsAKA Spore Plants

• These are the first plants that have adapted to have specialized tissues used to conduct water. This is called vascular tissue

Non-Seed Vascular PlantsAKA Spore Plants

• Vascular tissue is a type of tissue specialized to conduct water- this was a very important adaptation to allow plants to live on land– What are the two types of vascular

tissue?

Non- seed Vascular• Vascular tissue is a type of tissue

specialized to conduct water- this was a very important adaptation to allow plants to live on land– What are the two types of vascular

tissue?– Xylem, Phloem

Non-Seed Vascular Plants• Ferns, Club Mosses, Horsetails

Non-Seed Vascular PlantsAKA Spore Plants

• Non-seed vascular plants reproduce using spores which are found on the underside of their fronds.

• Fronds is what botanists call the leaves of ferns

Seed Plants • The two groups of seed plants are

the:– Gymnosperms – Angiosperms

Seed Plant adaptations• Seed plants have adapted to life

outside of water by:– Reproducing with flowers or cones– Pollination– Protecting embryos in a seed

Gymnosperms• Cone Bearing Plants

– Gnetophytes Gnetophyta– Cycads= Cycadophyta– Ginkgoes= Ginkgoephyta– Coniferophyta = Conifers

Gymnosperms

Conifer Ecology• Conifers thrive in habitats with

limited water because of several adaptations including long thin leaves (needles) coated with a hard waxy cuticle.

• Leaves do not fall in the winter. Older needles are gradually replaced by new ones (evergreen)

Name some plants:

Angiosperms• Almost 90% of living plants are

angiosperms• Angiosperm means “enclosed

seed”

Angiosperms• The fruit is a thick wall of tissue

surrounding the seed. The fruit is what has made angiosperms so successful.

• By using fruit to attract animals the angiosperms ensure the seeds will be dispersed

Angiosperms• There are two types of

angiosperms:– Monocots– Dicots

Angiosperms• Monocots-

– Single seeds– Parallel leaf veins– Floral parts in multiples of three– Fibrous roots

Monocot leaf

Angiosperms• Dicots

– Two cotyledons– Leaf veins are branched– Floral parts are in multiples of 4 or 5– taproots

Dicot Leaves

Seed Distribution• Seeds are distributed in plants just

like spores are in fungi– Wind– Animals

Life Spans • Annuals- complete their entire life

cycle in one year• Biennial= two years, flowering

occurs during the second year• Perennials= many years

Biennials

Annuals

Perennials

Perennial• Buffalo grass of the north

American Plains has been growing since the end of the last ice age, or 10,000 years

Structure and Function• Structure & function: What

physical characteristics does something have? How do these physical characteristics influence it’s “job”

Structure & Functionin plants

Three main parts of plants1. Roots2. Stems3. Leaves

Structure & Function• Roots

– The job of a root is to anchor the plant to the soil, absorb minerals, conduct water and nutrients, and store food

Fibrous / Tap

Structure & Function • Tap Root- Many dicots have a

taproot system consisting of one large vertical root that produces tiny hair like horizontal roots.

Structure & Function• Fibrous Roots- Monocots including

grasses have fibrous roots which spread out like a mat just below the soil surface.

Structure & Function• Both types of roots are designed to

anchor the plant. Both do so in different ways

• A similarity of both root systems is that they absorb most of the water through root hairs.

• Roots hairs increase surface area

Structure & Function • Stems- A stem has an alternation

of NODES- that point at which leaves are attached, and internodes- the stem segments between the nodes.

Xylem / Phloem

Plant Tissue

Multicellular VS. Unicellualrthe thing that distinguishes multicellular organisms from unicellular organisms is cell specialization. Plants have cells that are specialized for transporting nutrients.

Structure & Function • Veins

– Each vein in a plant has two types of tissue;• Xylem- transport water and dissolved

minerals upward from the roots• Phloem- transports food made in the

leaves to non-photosynthetic parts of the shoot system

Plant Cells• Tracheids & Vessels

– Xylem- is composed of two cell types, Trachieds & Vessels- Both cells are dead. Before they die they form rings that can stretch as the plant grows

Structure & Function• Leaves are the main

photosynthetic organs of plants.• Leaves are made up of a flattened

Blade, and a petiole which attaches the leaf to the node of the stem

Structure & Function • Monocot & Dicot

leaves differ in how their veins are arranged

• Monocots veins run parallel

• Dicot veins are netlike

* Leaf Morphology • Arrangement of leaves on a stem

can be • Opposite• Alternate • Whorled

Leaf Anatomy• The surface of the leaf is covered

in a waxy cuticle, this is to prevent water loss

Leaf anatomy• The cuticle is interrupted by guard

cells and stoma• Stomata allow gas exchange

between the air and the photosynthetic cells inside the leaf

• Stomata are also how leaves undergo transpiration

Surface of a leaf

Stomata

Guard Cells

Transport • Plants lose a great volume of water

during transpiration. An average sized maple tree looses 200L of water an hour

Transport• Pushing- Root pressure “pushes”

nutrients & water “up” the plant• Pulling- Transpiration-Cohesion-

Tension Mechanism- capillary action

Reproduction• Gymnosperms reproduce with

cones

Gymnosperm reproduction

Reproduction• Flowers are the reproductive

organs of angiosperms

Seed dispersal• Seed are dispersed though wind,

water, and animals.

Plant Hormones• Plant hormones are chemical

substances that control a plants patterns of growth and development, and the plants responses to environmental conditions

Plant Hormones• Auxins- control phototropism

Phototropism is the tendency for a plant to move toward a source of light

Phototropism

Plant hormones• Auxins also control gravitropism

• Gravitropism is the tendency of a plant to grow in a direction in response to the force of gravity

Gravitropism

Plant Hormones• Cytokinins- stimulate cell division

and cause dormant seeds to sprout

Plant hormones• Gibberellins- produce a dramatic

increase in size, particularly in stems and fruit

Tropisms• Thigmotropism- a plants response

to touch (vines wrapping around things)

Photoperiodism• Photoperiodism in plants is

responsible for the timing of seasonal activities such as flowering and growth