Download Botany

Botany
Study of Plants
I
Are all plants the same?
A. All plants share some common
characteristics.
1.
2.
3.
All plants are photosynthetic autotrophs. In order
to photosynthesize, plants use special cell
structures called chloroplasts. Chloroplasts are
filled with a pigment called chlorophyll that
transfers light energy into chemical energy. The
plant then uses the energy to make sugars, which
store the energy for later use in respiration.
All plants are multicellular. Plants are made of
eukaryotic cells with cell walls surrounding the cell
membrane for protection against cell lysis, large
vacuoles near the center of the cell to store water,
and chloroplasts in specialized cells within the
plant body.
Plants are common producers in ecosystems,
forming the base of all terrestrial food webs.
I
Are all plants the same?
B.
Plants are divided into groups based
on differing characteristics.
1.
The first main division of plants is based
on the presence of vascular tissue.
Vascular tissue consists of specialized
cells joined into tubes that aid the plant in
moving water and nutrients throughout
the plant body.
a.
b.
Nonvascular plants lack vascular tissue.
Vascular plants have two basic types of
vascular tissue: xylem (which carries
water) and phloem (which carries
nutrients).
I
Are all plants the same?
2.
Vascular plants can be
further divided based on
the means of reproduction:
a.
b.
c.
Paw-Paw
cashew
Seedless vascular plants
reproduce using spores (ex.
fern).
Gymnosperms are vascular
plants which store seeds in
cones (ex. spruce).
Angiosperms are vascular
plants which store seeds in
fruits which develop from
flowers (ex. daisy).
Review Questions
1.
Name three characteristics shared by all plants.
Multicellular, autotrophs(photosynthetic) eukaryotic
cells with cholorplasts.
2. What are the two main divisions of plants?
Vascular plants and Nonvascular plants
3. How are vascular plants further sub-divided?
Angiosperms and Gymnosperms
4. What is an angiosperm?
A vascular plant that stores seeds in fruits that develop from
flowers.
II
Are plants alive?
A.
Transport describes how plants get what they
need to the cells and remove wastes from the
cells.
1.
2.
Non-vascular plants depend on osmosis to take in
water and diffusion to move other important
substances (sugars) to the cells. Therefore, the
plant must be small and grow in mats which have
a spongy quality which help to absorb and retain
water.
Vascular plants have a system of tubes and
vessels which allow them to transport water and
nutrients throughout the plant body. Therefore,
the plant can grow much taller.
a.
b.
Xylem is the vascular tissue that transports water
from the roots to the rest of the plant body.
Phloem is the vascular tissue that transports
nutrients (sugars produced through photosynthesis)
from the photosynthetic structures (ex. leaves) to
the rest of the plant body.
II
Are plants alive?
B. Respiration describes the
process by which plants (and all
other cells) transform the stored
energy of sugars into the quick
energy of ATP. In order to
respire plants need to obtain
oxygen (from environment
and/or photosynthesis) and
sugars (from photosynthesis).
II
Are plants alive?
diffusion/osmosis animation
C.
Excretion describes how the plant rids itself of
wastes.
1.
Non-vascular and vascular plants get rid of excess
gases produced by photosynthesis and cellular
respiration by diffusion. Vascular plants, however,
have special microscopic openings on the surface of
the leaves through which the diffusion takes place.
These openings are called stomata and are formed
by two adjacent guard cells.
2.
Plants can also store waste in the vacuole or in
organs which are destined to fall off or die (ex.
leaves in the autumn). Some plants excrete waste
products into the soil, occasionally using the wastes
as chemical weapons against other competing plants
Black Walnut Toxicity to Plants
, Humans and Horses
Review Questions
1.
How do non-vascular plants transport water?
osmosis
2. What vascular tissue transports water?
xylem
3. What do plants need in order to respire?
oxygen and glucose
4. From where do plants get oxygen for cellular respiration?
photosynthesis
5. What are stomata?
Openings on the underside of the leaf where gases are
exchanged and water evaporates from the plant.
II
Are plants alive?
D.
E.
Synthesis describes how organisms build
necessary molecules. Plants produce
sugars through photosynthesis which
requires gas exchange through the
stomata. Plant cells must also produce
essential cell molecules such as
phospholipids for membranes and proteins
for enzymes.
Nutrition describes how organisms break
down food. The sugar produced in
photosynthesis may be stored or moved
throughout the plant to be broken down and
used during cellular respiration.
Apical Meristems
II
Are plants alive?
F.
Regulation describes how organisms
control body processes.
1.
Plants produce hormones which regulate
their growth and development and may
control responses to stimuli.
a.
b.
c.
Auxins are hormones that allow for
elongation of the cell. This increased
flexibility allows the plant to bend
Cytokinens are hormones that promote
rapid cell division. These hormones are
found in rapidly growing regions of the
plant such as the apical meristems (plant
tissue in root tips and buds of shoots that
supply cells for the plant to grow in
length).
Ethylene is a hormone that promotes fruit
ripening. Because ethylene is a gas, it
can affect nearby fruit.
II
Are plants alive?
2.
•
Plant tropisms are plant growth responses to
external stimuli. These responses are made
possible by hormones such as auxin.
a. Phototropism describes a plant’s response to
light.
Ex. Leaves and stems grow toward the light
to help with
photosynthesis.
b. Gravitropism/Geotropism describes a plant’s
response to
gravity.
Ex. Roots grow toward the force of gravity
but stems grow
against the force of gravity.
c. Thigmotropism is a response to constant
contact.
Ex. Vines wrap around an object, such as a
mailbox.
Plant Movement Animations
Review Questions
1.
Give two examples of important substances plants
need to synthesize.
proteins, sugars, phospholipids
2. How does a plant use the sugar produced in
photosynthesis?
To make ATP through respiration
3. What regulates the growth and development of plants?
Hormones
4. What term describes a plant’s response to constant
contact?
Thigmotropism
Plant Life Cycle Animation