Transcript ON Science Chapter 2 Plant Cells to Systems Note

UNIT 1
Tissues, Organs, and
Systems of Living Things
Chapter 1: Cells and
More Cells
Chapter 2: Plants:
From Cells to Systems
Chapter 3: Animals:
From Cells to Systems
CHAPTER 2 Plants: From Cells to Systems
In this chapter, you will investigate:
• how plant cells specialize to form different tissues
• the link between cells, tissues, organs, and systems in plants
• the function of plant tissues and organs
• how organs work together to meet the needs of a plant
• diseases that threaten plant tissues and organs
Activity 2-1 Observing Plant Growth
(Page 55)
What happened to the seeds
when they were soaked in
water?
What did you observe inside the
“split open” seed?
What will happen to the seed as
it continues to grow?
Copyright © 2010 McGraw-Hill Ryerson Ltd.
2.1 Plant Cells, Tissues, and Organs
(Page 57)
Cell Specialization – the process by
which cells develop from similar
cells into cells that have specific
functions within a multicellular
organism
• Cells specialize as a result of
producing different proteins.
http://genomics.energy.gov
• Different genes code for different
proteins and not all genes in a cell
are translated into proteins.
Cell Differentiation – a stage of
development of a living organism
during which specialized cells form.
Copyright © 2010 McGraw-Hill Ryerson Ltd.
Specialized Cells and Tissues in Plants
(Page 58)
Tissue – a cluster of similar
cells that share the same
specialized structure and
function
Organ – a combination of
several types of tissue working
together to perform a specific
function
Meristematic Cell – an
undifferentiated cell that can
form specific specialized cell.
Lifelong ability to produce the
cells can become new tissue and
organs aka STEM CELLS
Specialized Cells and Tissues in Plants
(Page 58)
Repair , Replacement , and Growth
(Page 59)
“Buds” and “Type of Growth” -auxin
is a plant growth hormone that triggers
growth by causing rapid division of
meristematic cells in roots and branches
The plant grows
upward, “getting
taller” due to
growth of the
terminal bud
Plants grow upwards,
downwards and outwards
The plant grows
outward or “thickens”
when the terminal bud
is removed and lateral
buds begin to grow.
Parts of a Leaf
(Pages 60-62)
Waxy cells: protections
water retention
Contain chloroplasts
and mitochondria
Water and mineral transport
Sugar transport
Contains spaces which house
gases needed of produced by
photosynthesis
Opening CO2 to enter
and O2 + H2O to exit
Control opening of
stomata
Transpiration
(Page 61)
Transpiration – the evaporation of water from the leaves through
the stomata; “plant sweat”
Read pages 57 to
62 and answers
questions on page
62 #1-4
Chloroplasts
Chloroplasts – the
organelles within plant
cells that use the Sun’s
energy to chemically
convert carbon into
glucose through
photosynthesis.
Thylakoids - contain
light trapping
chlorophyll molecules
and are the site of
photosynthesis;
thylakoids are arranged
in stacks called grana
(granum singular).
(Page 63)
Stems
(Page 64)
A plant’s stem has two main functions:
1. physical support
Xylem cells are fortified
2. transportation of sap (water, nutrients
with lignin to add support and sugars)
to the stem. Phloem cell
walls are porous to allow
material exchange
Read pages 63 to 64 and answer
questions on page 64 #5-8
Roots
(Page 65)
A plant’s root has three main
functions:
1. to anchor the plant in the ground
2. to take up water and minerals
from the soil
3. to store energy and nutrient
supplies for later use
Types
of Roots
Tap Root
Fibrous Root
Cross Section of a Typical Root
(Page 65)
These are the root hairs which
are the main site of water and
mineral absorption
These are the endodermis cells which
help control the transport of minerals
from the cortex to the vascular tissue
Contain very few chloroplasts; are
used to store starch for the plant. Lots
of spaces between cells for water and
minerals to flow to endodermis
Plants Under Attack: “Diseases of Plants”
(Page 66-67)
Plant tissues and organs can be infected by viruses which cause
diseases in the plant. Not all plant diseases are fatal or even
damaging to the plant, but they can cause visible effects.
Brown Rust
Beautiful
Rembrandt
tulips get their
stripes from a
transmittable
virus.
Plant Galls
(Page 66-67)
Plant galls are an abnormal growth of plant tissue caused by insects,
fungi, bacteria or viruses. Galls are similar to tumors in animals. The
attacking micro-organisms utilize the plant’s resources for the
development of their offspring or for their own survival (parasites).
Galls do not spread to other tissues in the plant and are rarely fatal.
Gall on a the leaf of
a currant plant
Gall on a mature
tree trunk
Gall on a the stem of a
blackberry plant
Flowers
(Page 68)
The main function of a plant’s flowers is reproductive. Flowers:
• produce sperm and eggs for sexual reproduction
• attract insects and other animals for pollination
• produce seeds and sometimes fruit after pollination
Section 2.1 Review
(Page 69)
Concepts to be reviewed:
• how meristematic cells differentiate into specialized plant
cells
• the characteristics of dermal, ground, and vascular tissues
• the four types of plant organs: root, stem, leaf, and flowers
• the process of photosynthesis
Read pages 65 to 69 and
answers questions on
page 69 #1, 3 - 7
Section 2.2 Plant Organ Systems
(Page 70)
System – a group of tissues and organs that perform specific
functions
Shoot System –
supports the plant,
performs
photosynthesis,
and transports sap
Root System –
takes in water &
nutrients from the
soil and transports
them to the shoot
system
Copyright © 2010 McGraw-Hill Ryerson Ltd.
Moving Water Through the Systems
(Pages 72-74)
“The push from below” – Water enters the root by osmosis and
moves toward the centre of the root into the xylem vessels. The
pericycle prevents the water from moving backward. Root
pressure builds up in the xylem and pushes water “up.”
Tiny root
hairs increase
the surface
area of the
root.
Copyright © 2010 McGraw-Hill Ryerson Ltd.
Moving Water Through the Systems
(Pages 73-74)
“The pull from above” – While the roots push the water
column from below, the leaves pull from above.
Transpiration aids in this process by making room for
more water from the xylem to move into the leaves,
pulling the water column in the xylem up.
Water’s unique properties also aid in moving water up the
xylem. Cohesion, the ability of water molecules to cling
to one another, holds the water column in the xylem
together. Adhesion, the ability of water to stick to certain
surfaces, allows water molecules to cling to the xylem
walls which helps prevent the water from flowing back
down into the roots.
Moving Water Through the Systems
(Page 74)
The Movement of Maple Sap
(Page 75)
In the spring, sucrose from the roots flows up the phloem to help
produce leaf buds. In the summer and fall, the leaves produce
glucose which combines with other molecules to produce sucrose,
that moves down the phloem to be stored in the roots as starch.
Glucose
Glucose
Sucrose
Sucrose
Starch
Starch
Section 2.2 Review
(Page 76)
Concepts to be reviewed:
• the function and characteristics of the root and shoot systems
• the function and properties of xylem and phloem tissue
• the tissues and processes involved in moving water and nutrients
• the movement and storage of the products of photosynthesis
Read pages 70 to 75 and answer questions
on page 72 #1-4 and page 76 # 1-2, 4-6, 8
Chapter 2 review tomorrow.
Chapter 2 Quiz on Friday, November 19.