Vascular plants have roots & shoots that grow from ______.
Their tips (apices)
Name 4 functions of the root.
1. Anchors plant
2. Penetrates soil to absorb water & minerals
3. Roots can exert huge forces as they grow
4. Roots are adaptions to living on land
Name 4 functions of the shoot.
Stems are scaffold for positining leaves
Leaves are main site of photosynthesis
Flowers, fruits, and seeds formed on shoot
Repeating unit of vegetative shoot is: internode, node, leaf, and axillary bud (but not reproductive unit).
3 types of tissue for composing roots and shoots:
1. Dermal tissue= epidermis
2. Ground tissue= storage, photosynthesis, secretion, forming fibers for support and protection
3. Vascular tissue= conducts fluids and dissolved substances
What are meristems?
Specialized cells in the root and shoot apices and other parts of the plant.
Meristems in plants act like what in humans?
Like stem cells.
A _____ cell divides to give rise to a differentiating daughter cell and a cell that remains as a _____ cell.
Meristem.
Apical meristems:
Involved with extensions of roots and shoots
Apical meristems are located ____.
at tips of roots and stems
Where are new cells added in plants?
Added at the tips
Primary tissues in plants are derived from what?
Apical meristems
The primary plant body is an extension of?
The root and stem
Root cap:
Protects delicate cells of root apical meristem; sloughed off and replaced as root grows through soil
Leaf primordia
Shelters tender growing shoot apical meristem from desiccation
The apical meristem gives rise to three types of tissue:
1. Protoderm - forms epidermis
2. Procambium - produces primary xylum and phloem
3. Ground meristem - differentiates into more ground tissue
Xylum:
Transports water
Phloem:
Transports nutrients
______ meristems are found in horsetails and corn. They are in the internodes and add to the length of the internodes.
Intercalary
Lateral meristems are involved with what?
Involved with increase in root and shoot diameter known as secondary growth
Lateral meristems form from _____ _____ that is derived from _____ ______.
Ground tissue
Apical meristems
(Monocots/Dicots) are the exception to lateral meristems and secondary growth.
Monocots
Secondary growth can increase girth in ________ plants, but the effects are most striking in ______ plants.
Non-woody
more striking in Woody plants
Woody plants have two lateral meristems:
1. Cork Cambium: contributes to outer bark of tree
2. Vascular cambium: located just beneath bark; produces secondary vascular tissue
____ ____ is the main component of wood.
Secondary xylem
Secondary phloem is located where?
Close to the outer surface of woody stem
What happens if you remove the bark of a tree?
Possible damage to secondary phloem, which may eventually kill the tree.
Most of the trunk, branches, and older roots of trees and shrubs are what type of tissue?
Secondary tissue
The secondary plant body is made of?
All the secondary tissues
How thick is dermal tissue?
Usually one cell layer thick in most plants
Dermal tissue forms ___?
Outer protective covering of plant
The cuticle of dermal tissue is composed of ___. Why?
Cutin. To protect young, exposed parts of plants
Why might desert succulents have several layers of wax in their dermal tissue?
To curb water loss and to help block UV raditaion
Dermal tissue on plants sometimes forms...?
Tree bark. Sometimes.
Give 3 examples of dermal tissue:
Guard cells
Trichomes
Root Hairs
Guard Cells:
paired, sausage-shaped cells that flank a stoma (opening) on leaves, stems, and fruits of plants.
Allow passage of oxygen and carbon dioxide and diffusion of water in vapor form
Guard cells contain _____ unlike other epidermal cells.
Chloroplasts
Is stomata more common on the upside or underside of leaves? Why? Give the exception.
Commonly found on the underside of leaves to minimize water loss. Water lilies are the exception.
Trichomes:
hairlike outgrowths of the plant epidermis
found frequently on stems, leaves, and reproductive organs
What is the function of trichomes on plants?
Helps keep surfaces cool, reducing water evaporation, protecting from UV radiation and high intensity. Serves as a buffer against temperature fluctuations.
____ trichomes may secrete sticky or toxic substances.
Glandular trichomes
Root hairs:
Extensions of epidermal cells, but NOT a separate cell.
Increases the surface area to maximize water and mineral uptake.
What are the 3 types of ground tissue in plants?
1. parenchyma
2. collenchyma
3. sclerenchyma
What does "chyma" mean?
"to fill" or "filling"
____ is the most common type of plant cell. It functions as storage of food and water, photosynthesis, and secretion.
Parenchyma
______ cells may live for many years (over 100 years in some cacti!).
A. parenchyma
____ is found in stems and leaf petioles.
B. collenchyma
_____ cells contain lignin that makes the cell walls more rigid.
A. sclerenchyma
Most of the cells in fruits such as apples are _____.
B. parenchyma
What is photosynthetic parenchyma called? Where is it found?
Chlorenchyma-- found in leaves and outer parts of herbaceous stems.
Give an example of Collenchyma
Celery "strings"
____ has tough, but flexible cells that support plant organs allowing them to bend without breaking.
A. collenchyma
Which of the following have living protoplasm and can live for many years?
B. parenchyma and collenchyma
Xylem is made up of ____ and ____.
Vessels and tracheids
How does water move through xylem?
Roots-->shoots-->leaves
Transpiration:
Diffusion of water vapor from a plant
Phloem is composed of ___ and ___.
Sieve cells and sieve tube members
Roots have 4 regions:
1. root cap
2. Zone of cell division
3. Zone of elongation
4. Zone of maturation
What region of the root contains the apical meristem?
The zone of cell division
What region of the root extends the root through the soil?
The zone of elongation
In what region of the root do cells become differentiated?
The zone of maturation
What region of the root protects the root and functions in perception of gravity?
The root cap
____ consist of a single large root with smaller branching roots
Taproots
Fibrous root systems:
Made up of many small roots of similar size
Adventitious roots:
Roots that arise from the stem or some place other than of the plant. Adventitious roots can function in support, stability, acquisition of oxygen, storage of food and water, or parasitism of a host plant.
Stems:
Support for above ground organs in plants
____ carry leaves and flowers and support the plant's weight. Leaves are attached to the ____ at the nodes.
Stem
Leaf arrangement may be:
1. alternate
2. opposite
3. whorled
Most often, leaves are arranges spirally around the stem approx. ____ apart.
137.5°
This angle relates to the golden mean, a mathematical ratio found in nature. It is possible that this may maximize the exposure of leaves to the sun.
Organization of ______ _____ is a major distinctive factor between monocots and eudicots (dicots).
Vascular bundles
Vascular bundles are scattered throughout the ground tissue of the stem. (Monocot/Eudicot)
Monocot
Vascular bundles are arranged in a ring around the outside of the stem. The interior of the stem is pithy. (Monocots/Eudicots)
Eudicots
(Monocots/eudicots) do not have secondary growth.
Monocots
(Monocots/Eudicots) exhibit secondary growth as the vascular cambium produces secondary tissues. This shows up as annual growth rings.
Eudicots
What is the purpose of a modified stem?
To carry out vegetative propagation and to store enutrients
Bulbs:
Swollen underground stem consisting of fleshy leaves attached to small knoblike stem with adventitious roots at base.
Examples of bulb stems:
Onions
Lilies
Tulips
Corms:
Look like a bulb, but when cut there are no fleshy leaves.
Stems with brown, papery nonfunctional leaves on the outside and some adventitious roots
Examples of Corms:
Crocus
Gladiolus
Rhisomes:
Horizontal stems that grow underground
Adventitious roots grow from the lower surface
Examples of Rhizomes:
Perennial grasses
ferns
bearded iris
Runners and stolons:
Horizontal stem with long internodes that grow just above the surface of the ground
Example of Runners and stolons:
Strawberries
Tubers:
tips of rhizomes swell and become tubers
The "eye" of a potato is evidence of where a leaf formed when the tuber started to grow
The "eye" is an axillary bud and will grow into a new potato plant.
Example of tubers:
Potato
Tendrils:
Twining stems that aid in climbing
Tendrils of peas and pumpkins are modified leaves
Examples of tendrils:
Grapes
English Ivy
Peas stems
Pumpkin stems
____ are the primary sites of photosynthesis.
Leaves
True or false: Leaves have a determinate structure
true
they stop growing at maturity
Most leaves have _______ symmetry resulting in more surface area for photosynthesis.
Dorso-ventral
Blade of the leaf:
Main part of leaf
Petiole of leaf:
Stalk that attaches leaf to main stem of plant
Vein of leaf
Vascular bundles made of xylem and phloem
(Monocots/Eudicots) have parallel leaf veins.
Monocots
(Monocots/eudicots) have netted or reticulate veins.
Eudicots
Simple leaves:
blades are not divided
Compound leaves:
Blade divided into leaflets
Leaf tissue:
1. epidermis with guard cells
2. vascular tissue
3. mesophyll (site of photosynthesis)
Modified leaves include:
Floral leaves (bracts)
Spines
Reproductive leaves
Insectivorous leaves
Floral leaves aka ?
Bracts
Surround the true flower and act as showy petals
Poinsettia & Dogwood
Spines:
Not the same as thorns or prickles
Modified leaves on cacti and some other plants
Reduce water loss and can deter predators
Reproductive leaves:
Little plantlets growing along margins that when separated can grow full-sized plants
Kalanchoe
Insectivorous leaves:
trap insects to provide supplemental nutrition for plant
These plants often live in acid swaps that don't provide all the nutrients the plant requires
