28 Jan. 2013Intro-Plants.ppt1 INTRODUCTION TO PLANTS Kingdom Plantae.

28 Jan. 2013 Intro-Plants.ppt 1

INTRODUCTION TO PLANTS

Kingdom Plantae


Plants are different from animals!

Be prepared to Journal…


Plants are different

• Cell walls of cellulose – complex carbohydrate

• Acquire energy by photosynthesis– Chloroplasts with

chlorophyll a, b– Chlorophyll reflects

green part of visual spectrum

Journal the following:

• Different structural adaptations of plants?

• Different life cycles in a plant: sporophyte vs. gametophyte

• How Plant life cycle is different than animal life cycles?

• What is the good and bad about asexual propagation?




• Plant body– Shoot: stem (nodes, internodes),

leaves, reproductive structures (flowers, cones, etc.);usually above ground

– Root: usually below ground, in soil

• Variations


Plant Body

• Shoot system– Stem & branches– Leaves– Nodes & internodes– Reproductive

structures

• Root system– Primary roots– Branch roots



• Plant body: Shoot & Root with vascular tissues Xylem

• water & minerals UP

Phloem • sap DOWN

Cambium • cell division for xylem

& phloem



• Growth at meristems• Apical meristem

• ”primary” growth (length)

• Lateral meristem = vascular cambium• “secondary” growth

(girth)


Plant Life Cycles are different

Alternation of generations



• Life Cycle = Alternation of generations.Sporophyte generation (diploid, 2n)Gametophyte generation (haploid, 1n)


Sexual Life Cycle

• Generalized life cycle of sexually reproducing species. Fertilization Meiosis


Animal Life Cycle

• Multicellular diploid Zygote, embryo, young (larva), adult

• Unicellular haploid sperm or egg


Plant life cycle

• Alternation of generations:

• Diploid sporophyte• Haploid gametophyte

multicellular sperm or egg


Plant life cycle Example: fern


Plant life cycle Example: flowering plant

Asexual propagation• Plants often reproduce

asexually– runners, – rhizomes, – tubers– roots form new shoots– fragmentation (willow,

privet, Forsythia)

• Used by nurseries to propagate varieties– ornamental plants (roses,

crepe myrtle)– fruit trees (apple, etc.)



Asexual propagation

• Advantages:• One individual can reproduce• Copies a successful genome exactly!

• offspring are clones of parent;• offspring expected to be as successful as

parent

• May be faster • no time for courtship, pollination, etc.


Asexual propagation

• Disadvantages:• All offspring are genetically identical. • If environment changes, all are equally

disadvantaged.

• (Sexual reproduction produces variation in offspring. Mixes genes from two parents.)

28 Jan. 2013Intro-Plants.ppt1 INTRODUCTION TO PLANTS Kingdom Plantae.

Documents