PLANT STRUCTURE &

FUNCTIONChapter 17

ANGIOSPERMS – FLOWERING PLANTS Human civilization would not have been

possible without the development of cropsAllowed societies to settle in one areaGenerated calories sufficient to shareThis in turn freed some individuals to

specialize in other things like art, pottery, cloth, metals

If stationary, need to determine how to share that area and resources – need government

Civilizations formed where agriculture developed first – usually specific crops can be identified Wheat, barley, corn, etc.

ORGANS OF A PLANT

MAJOR DIVISIONS OF FLOWERING PLANTS

IS THIS A MONOCOT OR A DICOT?

A. Monocot B. Dicot

ORGAN MODIFICATIONS – SOME EXAMPLES

Leaves: tendrils and spines

Roots: sugar beet, carrot, turnip, sweet potatoes

Stem: rhizomes – horizontal and near surface; stolon - above ground

FLOWER = MODIFIED LEAVES

PLANTS HAVE 3 BASIC TYPES OF TISSUES

1ST = DERMAL TISSUE

2ND TISSUE TYPE: VASCULAR

3RD TISSUE TYPE: GROUND

PLANT TISSUES - IN ROOTS

WATER AND NUTRIENTS ENTER THE ROOT AND ARE TRANSPORTED BY XYLEM Flow of water

and nutrients is regulated by cells

Extracellular movement is blocked by a waxy barrier, the Casparian strip

Thus all movement is regulated by cells in the root

PLANT TISSUES - IN STEM

PLANT TISSUES – IN LEAVES

REGULATION OF TRANSPIRATION & GAS MOVEMENT INTO AND OUT OF LEAVES

And Flowers are modified leaves

HOW DOES A PLANT BREATHE?

a) A plant breathes through specialized leaves called tendrils

b) CO2 is taken in and O2 released through root hairs

c) Vascular tissue called phloem moves gases in and out of the plant’s leaves and stems.

d) Gas exchange in and out of the plant’s body occurs via the leaf stomata

e) Both c and d are correct

IN GENERAL, PLANT DERMAL TISSUES ARE FOUND

A) at the surface of plant organs. B) near the center of the plant stems and

roots. C) lining the vascular tissue. D) throughout the plant body. E) only in plants that have secondary

growth.

PLANTS CAN GET NITROGEN FROM FUNGI, TOO

Some fungi live in plant roots in a mutualistic relationshipFungus gets sugars Plant gets increased

water and ion uptakeSome fungi also

secrete antibiotics

ANIMATION FOR CH 17 Plant special features Transportation of water and minerals in

plant Role of xylem and phloem in

transportation and meeting the needs of the plant

FOR HEALTHY PLANT NUTRITION: SOIL CONSERVATION IS IMPORTANT

Maintaining a healthy soil

Sustainable use of water and nutrients

Protect against water and wind erosion

Minimize use of artificial fertilizers and pesticides

On a trip to the Southwest, you and a friend collect some seeds from a piñon, which is a type of pine tree. Your friend also gathers a small bagful of soil from under the piñon tree. Back home, both of you plant your seeds in commercial sterilized potting soil, but your friend adds a spoonful of the collected dirt to each of her pots. Her seedlings do better than yours. Which of the following is the likeliest reason?

A) Pine seedlings are better adapted to the sandy soil of the Southwest than to commercial potting mix. B) The soil from the Southwest probably contained macronutrients missing from the potting mix. C) The soil from the Southwest probably contained nitrogen-fixing bacteria that colonized the seedlings' root nodules. D) The soil from the Southwest probably contained fungi able to establish a mycorrhizal association with the seedlings' roots. E) The soil from the Southwest probably contained the eggs of worms

and other soil animals.

READ CHAPTER 18 GROWTH & REPRODUCTION IN PLANTS

GROWTH & REPRODUCTION

IN PLANTSChapter 18

PLANTS CAN REPRODUCE:

Asexually Sexually

Advantages: faster, less energy, preserves winning allele combination.Disadvantage: Reduced genetic variation

POLLINATION: TRANSFER OF POLLEN TO THE STIGMA OF A FLOWER

http://www.youtube.com/watch?v=gEcv3dBuOe4

REPRODUCTION – REVIEW

DEVELOPMENT OF EMBRYO

(Protective)

Ovary develops into fruit

http://search.yahoo.com/search;_ylt=AveBa4WI3_S.poEk9h0kRIObvZx4?p=Touch+me+nots&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-701

Which of the following is TRUE about a sexually reproducing population?

a) It is energetically more efficient than asexual reproduction.b) “Winning alleles” are always preserved in the offspring.c) The population can better keep up with changing conditions.d) It is faster than asexual reproduction.e) There is no need to find a mate.

Which of the following is a likely way in which plants increase dispersal of their seeds?

a) Fruits are conspicuously colored.b) Fruits taste good.c) Fruit colors attract female birds.d) Both a) and b) are true.e) Both a) and c) are true.

What is the first step that occurs in the process of angiosperm reproduction after a pollen grain lands on a stigma of the correct species?

a) There is no pollen tube involved, the sperm cells move down the stigma to the ovaries.b) The first step after pollination varies depending on the species of the plant.c) The sperm cells immediately move down the pollen tube since the tube was previously formed.d) The sperm cells immediately fertilizes the egg cells that are located in the stigma.e) A pollen tube forms to carry the sperm cells toward the ovary.

GERMINATION OF THE SEED

PLANT GROWTH IS INDETERMINATE

Meristem = undifferentiated cellsLocated where plant

grows – buds and root tips

Primary vs Secondary growth

Lateral meristem of stems and roots Cork and vascular

cambrium

TYPES OF PLANT GROWTH

SECONDARY GROWTH

Meristem:

Vascular cambium comes from primary xylem.

Cork cambium comes from division of ground tissue cells just below the Epidermis

Wood = Secondary Xylem (both Heartwood & Sapwood)Heartwood = older,

more filled with thickened sap

Sapwood = younger Bark = Secondary

phloem, Cork Cambium, Cork, & Epidermis

HOW DOES A TREE GROW?a) Elongation of trunk, new leaves,

widening of branches and rootsb) Meristem divides in leaf tips, stem

nodes, root tipsc) New leaves, at root and branch tips,

widening of trunk and rootsd) Zone of differentiation has dividing

cells that enlarge stems and roots, new leaves, and enlarged vascular tissue in stems

IF YOU CARVE YOUR INITIALS IN THE TRUNK OF A TREE, WILL THEY MOVE UP AS THE TREE GROWS?

A) Yes, because a tree elongates from the ground up.

B) Yes, because secondary growth will cause them to move up.

C) No, because trees stop growing if they are damaged.

D) No, because elongation occurs in the tips of growing stems in the apical meristems.

E) Yes, because growth continues in all parts of a plant throughout its life.

WHAT IS PHYTOREMEDIATION?

A) The use of native plants to restore habitat for wildlife after disasters such as Hurricane Katrina.

B) The use of plants to clean up polluted soil and groundwater.

C) Treatment of soils and groundwater with chemicals to prevent plant death.

D) The use of plants to remove carbon dioxide from the atmosphere.

E) The use of plants to improve the appearance of devastated areas after disasters.

READ CHAPTER 19