Ch. 23 “Introduction to Plants”

I. Adaptations of PlantsA. Today’s plants probably evolved from

green algae.B. To survive on land, plants had to be able

to do three things:1. Absorb nutrients2. Prevent water loss

a. Cuticle-waxy protective covering of a plant b. Stomata-pores in the leaves that allow for the

exchange of gases. c. Guard cells-specialized cells that regulate the

opening and closing of the stomata.

Cross-section of leaf

3. Reproduce on land A. Pollen-contains the sperm and allows it to

be carried by wind or animals instead of water.

C. Vascular System-internal system of interconnected tubes and vessels for transporting food and water.1. phloem-transports food.2. xylem-transports water.

D. Seeds-structure that contains the embryo of the plant.

There are 4 advantages of seeds:1. Protection-surrounded by a seed coat.2. Nourishment-contain food for the plant

embryo.3. Plant dispersal-can spread by wind, water,

animals.4. Delayed growth-seed will not sprout until

conditions are favorable for growth.

E. Flowers-reproductive structure that produces fruits and seeds.1. Attract birds, animals, and insects to carry

pollen.2. Reproductive parts called stamen and pistil.

II. Kinds of PlantsA. Nonvascular Plants

1. Do not have a vascular system.2. Small size.3. Gametophyte generation is dominant.4. Need water for sexual reproduction.5. Examples include mosses, liverworts, and

hornworts.

B. Seedless Vascular Plants1. Have a vascular system2. Sporophyte generation is dominant3. Have spores with thick walls to prevent

drying out4. Examples include ferns, club mosses,

horsetails

C. Gymnosperms1. Seed plants that produce “naked” seeds in

cones.2. Have vascular system3. Examples include conifers, cycads, and

ginkgos.

D. Angiosperms1. Produce flowers2. Produce seeds enclosed within a structure

called a fruit. A. provide food, protect the seed, and help disperse

the seed.

3. Seeds contain a supply of stored food called the endosperm.

4. Classified into two groups:A. Monocots

Produce seeds with only 1 seed leaf (cotyledon) Flower parts in multiples of 3’s Leaves have parallel veins

crocus, corn, grass, tulips

B. Dicots-produce seeds with 2 seed leaves-flower parts in multiples of 4’s or 5’s-leaves with branching veins

roses, apples, beans

III. Plants in Our LivesA. All plant parts-roots, stems, leaves,

flowers, and fruit provide food.B. Wood for paper, lumber and fuelC. MedicinesD. Plant fibers make paper, cloth, and rope

The PLANT CellA – Vacuole – holds water

B – Cell wall – protection and support

C – Endoplasmic Reticulum – transport proteins

D – Nucleus – Control cell activities, Hold DNA

E – Mitochondria – Make energy into usable ATP

F – Chloroplasts – Convert CO2 into C6H12O6

G – Golgi Bodies – packages and distributes protein