Midterm 1 Flashcards
(97 cards)
1
Q
What is the importance of plants?
A
- Basic human needs: food, clothing, shelter, fuel and clean air
- All are directly or indirectly provided by plants
2
Q
What is the basic organization of life?
A
Atoms, Molecules, Cells
3
Q
Unicellular organisms
A
One cell performs every life
function: food capture,
photosynthesis, metabolism,
reproduction, etc.
4
Q
Multicellular organisms
A
Each cell has a specialized
function. Many similar cells
form tissues, multiple
tissues form organs.
5
Q
Prokaryotes
A
Don’t have membrane-bound
organelles
6
Q
Eukaryotes
A
Have membrane-bound
organelles
7
Q
Plants are Eukaryotes. Eukaryotic cells have…
A
- Membrane-bound organelles (compartments)
- Nucleus - contains the genetic material
8
Q
Animal cells
A
- No cell wall
- No large vacuole
- No chloroplasts
9
Q
Plant Cells
A
- Cell wall
- Large vacuole
- Chloroplasts
10
Q
Cell wall
A
- Made of cellulose
- Function: structure and protection
- Thin, flexible primary cell wall
- Additional thick, rigid secondary cell wall
11
Q
Plasma membrane
A
A selectively permeable barrier that regulates the
movement of substances in and out of the cell.
12
Q
Plasmodesmata
A
Small channels that connect neighboring cells
together for the exchange of chemical signals
13
Q
Nucleus
A
- Control center of the
cell - Stores genetic material
(DNA) - Instructions for making
different enzymes and
other proteins - Bound by a double
membrane—nuclear
membrane
14
Q
Chloroplast
A
- Specialized organelle where photosynthesis
occurs - sunlight + water + carbon dioxide = glucose/sugar
- Contains chlorophyll, a green pigment
15
Q
Variegated plants
A
some cells acquire
mutations which prevent the production of
chlorophyll
16
Q
Mitochondria
A
Site of cellular
respiration
* Sugar and starch is
broken down into
useable energy
* Similar in structure to
chloroplasts (inner
folded membrane)
17
Q
Vacuole
A
- Large fluid-filled organelle
- Occupies 90% of the
volume in mature cells - Maintains cell pressure
-
Stores nutrients and breaks
down waste products - Stores water soluble
pigments called
anthocyanins (purple and
red color)
18
Q
Mitosis
A
- DNA is duplicated
- Cell is split into two
- Both cells are genetically identical
19
Q
Plant tissues
A
Groups of cells that perform the same function
20
Q
Simple Tissue Types
A
- Parenchyma (most common)
- Collenchyma
- Sclerenchyma
21
Q
Three Primary Tissue Systems
A
- Epidermal Tissue
- Ground Tissue
- Vascular Tissue
22
Q
Parenchyma Tissue
A
- Living at maturity
- Most common type of cell
and tissue - Thin primary cell walls
- Large central vacuole
- Can take on many shapes
- Function in photosynthesis,
storage, and transport of
food and water
23
Q
Amyloplasts
A
organelles
that store starch
molecules (energy for
the cell)
24
Q
Collenchyma Tissue
A
- Composed of living
cells with thickened
primary cell walls -
Flexible support for
organs such as
leaves and
herbaceous stems
25
Sclerenchyma Tissue
* **Dead** at maturity
* Thick and rigid secondary
cell walls reinforced with
Lignin
* Function in support and
protection
26
Two cell types of sclerenchyma tissue
1. Fibers
2. Sclereids
27
Fibers
* Elongated
sclerenchyma cells
* Provide structural
rigidity and stiffening
to leaves, stems, and
roots
* Abundant in wood
28
Sclereids
* Sclereids (stone cells)
form the hard tissues of
nuts, seed coats, etc.
* Compact shape
* May be present
together with thin-
walled parenchyma
cells.
29
Epidermal tissue
* Outermost layer of cells,
the epidermis
* Complex
tissue:composed of
numerous cell types
* Covered with a waxy
cuticle layer to prevent
water loss
30
Epidermal tissue cell types
Epidermal
cells, root hairs, Guard
cells, trichomes
31
Epidermal cells
Covered with a **waxy cuticle** to prevent water
loss
32
Trichomes
Leaf hairs
33
Stomata
* Pores (holes) in leaves and stems where
gas exchange occurs and water evaporates
* When stomata are open, CO 2 enters the
plant, water and oxygen are released
34
Ground Tissue
* Present in most organs of the
plant, between the epidermal
tissue and vascular tissue
* Photosynthesis, storage,
support
35
Ground tissue types
1. Parenchyma
2. Collenchyma
3. Sclerenchyma
36
Vascular tissue
* Continuous tissue
throughout the plant
in which water and
sugar are transported
* Composed of
numerous cell types
37
Vascular Tissue types
* Xylem
* Phloem
38
Xylem
* Transports **water** and minerals
* Made of tracheids, vessel elements, fibers, xylem parenchyma
39
Tracheids
tapered at the ends, water passes between tracheids through thin areas in the cell wall called pits
40
Vessel elements
long tubular cells
open at both ends, arranged end to end forming vessels that function like water pipes
41
Phloem
* **Transports sugars** and other
organic substances
* Composed of sieve tube members, companion cells, phloem fibers, phloem parenchyma
42
Sieve tube members
long tubular cells with sieve plates in the end walls, arranged end to end, alive but lacking a nucleus
43
Companion cells
help sieve tube
members function
44
Primary Growth
* Apical Meristems
* Form primary tissues
* Plant increases in
length
* Tips of every branch
(and in leaf axils)
* Mitosis creates new
tissues
45
Phototropism and Auxin
Cell elongation results in the bending of the shoot toward the light
46
Cook Pine
* Native to New Caledonia
* Grown ornamentally worldwide
* Tree trunk leans toward the equator
(phototropism)
47
Functions of a stem
* **Transport** – water and sugars
through vascular tissue
* **Support** - holds leaves in
position for efficient
photosynthesis
* **Storage**– Ground tissue
stores energy and water for
later use
48
Internal Stem Structure
**Vascular Tissue** - Conducts water,
minerals, and sugar
**Pith**- Stem center (storage, support)
Cortex
** Cortex** - Outer portion of ground tissue
** Epidermis** - The outer most layer of cells*
49
Natural Fibers
* Hemp (Cannabis sativa)
* Grown for rope, paper,
clothing, sailcloth
* Strong and resistant to
water and sea water
50
The typical stem
The pattern of growth is
consistent as the main axis
of the plant develops:
Stem, Leaf, Bud
51
Modified Stems: Stolons
* **Horizontal above- ground stems**
* Function:
Vegetative Reproduction
52
Modified Stems: Rhizomes
* Horizontal **below- ground stems**
* Function:
Vegetative Reproduction
* produce new individuals at nodes below ground
53
Modified stems: Succulent stems
* round, fleshy, water-storing stems
* Function: Water Storage
54
Modified Stems: Bulbs
* underground storage stem with fleshy leaves
* Function: water and energy storage
55
Modified stems: Tuber
* The swollen end of an underground stem.
* Function: Water and
energy storage,
propagation from axillary
buds (”eyes” of a potato)
56
Modified Stems: Thorn
* Sharp and pointed stem (often a sharp axillary bud)
* Function - Physical protection against
herbivores and frugivores (fruit-eaters)
57
Root functions
1. Anchoring plant in soil
2. Absorption
3. Conduction
4. Storage
5. Hormone Production
58
Root systems: Taproot
* **one main root that grows downward**
* Carrots, radishes,
turnips, and beets
are examples
* Most Eudicots
59
Root systems: Fibrous roots
* have **many branch roots**. No single root is more prominent
than others.
* Wheat and corn are examples.
* Most Monocots (e.g. corn, wheat, rice, palms, onions)
60
Roots have
* a root cap that
protects the apical
meristem
* no nodes
* root hairs for H 2 O
absorption
61
Root cap
* Protects the root tip
* Produces lubricating mucigel
* Constantly sloughed off and
regenerated by apical
meristem
62
Root epidermis
* Provides protection
* Absorbs water and minerals from
the soil
* Absorption is facilitated by root
hairs
63
Examples of Monocots
* Lilies
* Orchids
* Irises
* Onions
* Bananas
* Ginger
* Grasses
* Agaves
64
Eudicots
* Roses
* Tomatoes
* Sunflowers
* Poppies
* Apples
* Oranges
* Avocados
65
Monocots vs. Eudicots (Stem)
* Monocots: vascular bundles are **scattered** throughout stem
* Eudicots: vascular bundles are arranged in a ** ring** around stem
66
Endodermis in roots
* Ring of cells surrounding
vascular cylinder
* Each cell of the
endodermis is surrounded
by a Casparian strip
impregnated with suberin
and lignin
* The Casparian strip is
impermeable to water
and solutes
67
Casparian Strip
* Substances entering or
leaving the vascular
cylinder must pass
through a plasma
membrane of the
endodermis cells
* Function: Regulation of
what enters and leaves
the vascular cylinder
* Effectively acts like a filter
for the root
68
Pericycle
* Layer of
meristematic cells
where lateral roots
develop
* Outer boundary of
vascular tissue, just
inside the endodermis
69
Lateral Roots
* emerges from the
pericycle inside of the
primary root
* maintains its connection with the vascular tissue
70
Root ground tissue
* Greatest volume of
most roots
* Function: storage of
starch
71
Root Symbiosis with Bacteria
Plant gets nitrogen,
bacteria gets sugar from
the plant
72
Root Symbiosis with Fungi
* Plant provides sugar for
fungi
* Fungi provide water and
nutrients with plants
73
Adventitious roots
Roots that arise from a tissue other than the pericycle
74
Prop Roots
Adventitious roots that stabilize the plant, like
stilts or lateral braces.
75
Aerial Roots
**Above-ground** adventitious roots that absorb
water or reach the soil and function as prop roots
76
Sugar Beet
* Artificially selected for a
high concentration of
sucrose
* Same species as chard,
and red beets (varieties)
* Beet sugar accounts for
40% of the world's sugar
production
77
Haustoria
* Penetrating roots of
parasitic plants
* Connect to vascular tissue of
host plant and steal water
and nutrients
* Mistletoes, wildflowers, etc.
78
Annuals
* most herbaceous plants that demonstrate only
primary growth
* entire life cycle takes place in one growing season.
79
Biennials: two seasons, germination to seed
* First season - energy storage in roots/stems
* Second season – stored energy used to produce
flowers and fruits
80
Perennials: plants that live for several years
* soft-stemmed plants that die back each
year, re-sprout each year from underground roots/stems
* Woody plants (shrubs and trees) that display secondary
growth in their stems and roots
* Monocots DO NOT display secondary growth
81
What happens to perennial plants after years of growth?
After several years of growth, perennial plants **start to form secondary tissues**
82
Secondary growth
Formation
of wood and bark
and widening of
stems and roots
83
Meristem
where growth occurs
84
Lateral meristems
1. Vascular cambium
2. Cork cambium
85
Cork
* Produced by the cork
cambium, which develops
from parenchyma cells in
the cortex
* Replaces the epidermis
* Cork cells are dead and
impregnated with suberin
wax (waterproof)
* Protective outer coating
* Constantly regenerated to
protect vascular cambium
86
Coast Redwood
* California's state tree
* Redwood lumber is
the most
commercially
valuable softwood
(gymnosperm wood)
* Coast redwoods are
the tallest trees on
Earth
87
What are the two state trees
* Coast Redwood
* Giant Sequoia
88
The Functions of Leaves
* Photosynthesis
* Regulate water loss - transpiration
* Many specialized functions
* Storage
* Protection
* Attraction
* Propagation
* Climbing
89
Early Development of a Leaf
Apical meristem forms **leaf primordia** (immature leaves) and **axillary buds** during primary
growth
90
Morphology of a Leaf
* **Blade** – expanded
portion of the leaf
* **Petiole** – leaf stalk
* **Stipule** – appendage
at the base of the
petiole
91
Leaf Venation
Vein: vascular bundles
in the leaves
92
Simple Leaves
The leaf blades are not divided
into separate parts (may be
deeply lobed)
93
Compound Leaves
Leaf blades are
divided into leaflets
94
Pinnately compound
leaflets arise from either side
of the rachi
95
Palmately compound
leaflets diverge from the
petiole tip (no rachis)
96
Rachis
an extension of the petiole
97
Bracts
leaves associated with
flowers. They help attract
pollinators
