Download Chapter 31

Chapter 31
Angiosperm Structure and Function
Kingdom Plantae: eukaryotic, multicellular, photosynthetic organisms. All
have cell wall, roots, stems, leaves, and gametangia to produce gametes,
reproduce sexually. Some of the oldest organisms on earth. Ex: redwood
over 100 feet, and giant sequoia or general Sherman is 84 meters tall and 10
m in diameter, 1700 years old.
Plants are divided into 2 major groups:
 Gymnosperms: -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Angiosperms: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- There are 2 types of angiosperms:
1. Monocotyledons: ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------2. Dicotyledons: ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PLANT BODY: Roots and shoots that are important in getting water,
photosynthesis, release of CO2 and O2.
1. ROOTS: below the ground, has root hairs.





2. SHOOTS: above the ground, stems, leaves, flowers ( reproductive
structures)
 Stems support leaves and flowers: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Modified stems; runners: grow along surface like strawberries;
rhizomes: brownish grow just below soil to store food; tubers:
large structures at the end of rhizomes for food storage.
 Leaves -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Buds are growth sites; terminal bud at the tip of a stem,
increases length. Axillary bud on the angles of leaves are
dormant. Apical dominance occurs when the terminal bud
inhibits the growth of axillary buds.
PLANT CELL:



1. Parenchyma cells:
 most abundant type of cell




2. Collenchyma cells:
 very thick primary cell wall


3. Sclerenchyma cells:
 rigid secondary walls ( lignin)




PLANT TISSUES: Vascular plants have tissues to move water and food up
and down the plant body. There are 3 tissue systems in plants.
1. Epidermis: skin
a.
b.
c.
d.
2. Vascular tissue:
a. xylem is
b. phloem
3. Ground tissue:
a.
b.
c.
d.
PLANT GROWTH: plants exhibit indeterminate growth, which indicates
that plants continue to grow as long as they live. Does not mean they are
immortal.
Plants are:
 Annuals:
 Biennials: com
 Perennials:
Growth in plants is possible because of tissues called ------------------------------. These are localized, unspecialized cells that divide and generate new
cells and tissues.
Primary growth: is growth in length ( root or shoot)
Secondary growth: increase in girth
Primary growth:
 Apical meristems:
 Root cap is a cone of
.
 These cells are involved in replacing cells that are scraped off and in
producing cells for primary growth downward of a root.
 Cells divide and then elongate to increase in length.
 Cells of the vascular tissue
Secondary growth:
 increases width and girth
 more seen in woody plants where the stems form thick layers of dead
xylem called wood.
 ------------------------------------------------- layer of actively dividing
cells between xylem and phloem
 vascular cambium gives rise to -------------------------------------------------------------------------------------------------------------------------------- secondary growth adds cells to each side of the vascular cambium.
 --------------------------------------------------------------- is inside the
vascular cambium, a new layer is produced every year ( seen as rings
that can estimate age of plant). makes up the wood of plants, causes
most of the growth in girth
 --------------------------------------------------- outside the vascular
cambium, part of the bark and does not accumulate during the years. It
is sloughed off.
 -------------------------------------------------- is the layer outside the
phloem, is part of the bark and gives rise to cork. cork is an outer
layer of plant where the cells are dead with thick walls to protect the
underlying stem.
TRUNK:
 Wood rays are parenchyma cells that transport water to the outer
living tissues.
 Heartwood is center of trunk, older layers of secondary xylem. Dead
cells filled with resin.
 Sapwood is younger secondary xylem that moves water.
 Bark is secondary phloem, cork cambium, cork.