ANGIOSPERMS

Morphology vs. Anatomy

• Morphology is the study of the external structure of plants– Ex. placement of leaves along a stem

• Anatomy is the study of the internal structures of plants– Ex. the arrangement of cells and

tissue within a leaf

MONOCOTS VS. DICOTSAngiosperms are split into 2 classes

• Monocots – single cotyledon (seed leaf)

• Dicots – two cotyledons

Cotyledon - seed leaf, one in moncots and two in dicots; •primary embryonic leaf within the seed in which nutrients for the new plant are stored (left- dicot, bean; right- monocot, corn)

Roots, Stems & Leaves• Roots

– anchor the plant into the soil– Absorb minerals and water– Conduct water and nutrients– Store food

Monocot root Cross section

Dicot Root cross section

• Stems–May be vegetative (leaves)

Stems may be floral (flowers)

Stems– Have alternation of nodes (points at

which leaves are attached)– Have internodes (stem segments b/w

nodes)

Modified Stems• Stolons are horizontal stems that

grow along surface ex. strawberry runners

• Rhizomes are horizontal stems that grow underground ex. Irises

• Tubers are enlarged ends of rhizomes that store food ex. potatoes

• Bulbs are vertical, underground shoots with fleshy leaf bases modified food storage

Monocot stem cross section

Dicot stem cross section

• Leaves– Main photosynthetic organs

of plants– Consist of a blade and a

stalk (petiole) which joins the leaf to the stem

– Grasses and many monocots lack petioles

• Some monocots have petioles

Venation• Monocots have parallel major veins that run

the length of the leaf blade• Dicots generally have a multibranched

network of major veins• All leaves have numerous minor cross veins

Modified Leaves

Spines, thorns and pricklesTendrils

SUMMARY

WHAT DO I NEED TO KNOW• Unifying characteristics of gymnosperms • Unifying characteristics of angiosperms• Explain how gymnosperms are adapted

for survival in a land environment with respect to the following– Alternation of generation– Roots– Stems– Leaves– seeds– Pollen– Vascular tissue

• Use specimens to differentiate between monocots and dicots

• Describe how angiosperms are adapted for survival in a land environment with respect to the following– Alternation fo generations– Flowers– Pollen– Enclosed seeds– Fruit– Roots– Stems– Leaves– Vascular tissue

• Compare the ways in which mosses, ferns, gymnosperms and angiosperms have adapted to a land environment

• TEXT– Read all the following…– Ch 22 all sections– Ch 23 most pictures, 23-4(modified roots),23-

5,23-7– Ch 25-1,25-2– Answer the following questions…– Page 484&485 all– Page 514&515 (mc#2,TF#1,2,4,5,6,8

WR#1,4 CM#3,4,6 CCT#2,3,4,5,7,8)– Page 548&549 (mc#1-4,7,8 TF#1,3-7

WR#1,3 CM#2,3,4,5,6,8 CCT#1,2,4,6,7