Stems Chapter 6 (Week 3 Lecture 3) Flashcards
What is a stem?
Woody twig consists of an axis with attached leaves.
______ is the area of the stem where the leaves are attached.
Node
What are the 3 types of stems?
Alternate or spiral, opposite (attached in pairs), whorled (in groups of 3 or more)
______ is the stem region between the nodes.
Internodes
The Leaf has a flattened ______ and is usually attached to the twig by ______.
Blade, petiole
Where is the axil located?
Angle between petiole and stem
The ______ ______ will become branches or flowers in flowering plants.
Axillary bud
What protects the buds?
Bud scales
Where is the terminal bud located?
Twig tip
What is the main function of the terminal bud?
Growth makes the twig longer
What are stipules?
Paired, often leaf-like appendages at base of a leaf
______ trees and shrubs, lose all their leaves annually.
Deciduous
______ ______ mark food and water conducting tissue within leaf scars.
Bundle scars
What are lenticels?
Parenchyma cells in cork for exchange of gases
Cells produced by stem meristem become ______ system with branches and leaves.
Shoot
True or False: The apical meristem is dormant before growing season begins.
True
True or False: The apical meristem is protected by bud scales and by leaf primordia.
True
What is the leaf primordia?
Tiny embryonic leaves that develop into mature leaves
True or False: Leaf primordia and bud primordia develop into mature leaves and buds.
True
What are traces?
A strand of xylem and phloem
How is a leaf gap or bud gap formed?
Each trace leaves a gap filled with parenchyma in the cylinder of vascular tissue
True or False: The narrow band of cells between the primary xylem and primary phloem may become vascular cambium.
True
What is another name for cork cambium?
Phellogen
What does the cork cambium produce?
Cork cells with suberin – to the outside Phelloderm (parenchyma-like) cells – to the inside
What is the stele?
Central cylinder of primary xylem, primary phloem, and pith (if present)
______ is the solid core, phloem surrounds xylem found in primitive seed plants, whisk ferns, club mosses and other ferns.
Protostele
______ is tubular with pith in center, commonly found in ferns.
Siphonsteles
______ are discrete vascular bundles in flowering plants and conifers.
Eusteles
What are cotyledons?
Seed leaves attached to embryonic stems
What is the function of cotyledons?
Store food needed by young seedling
What is the difference in stem for monocots and eudicots?
In monocots, vascular bundles are scattered in the stem. In eudicots, vascular bundles are in a distinct ring
______ are plants that die after going from seed to maturity within one growing season.
Annuals
What are 3 common characteristics of annuals?
Usually green, herbaceous plants
Most monocots are annuals, but many dicots are also annuals.
Tissues largely primary
Herbaceous dicots have discrete vascular bundles arranged in a ______.
Cylinder
True or False: In herbaceous dicotyledons, the vascular cambium arises between primary xylem and primary phloem that adds secondary xylem and secondary phloem.
True
Wood is ______ xylem.
Secondary
One years growth of xylem of woody dicotyledonous stems is know as ______ ring.
Annual
True or False: On woody dicotyledonous stems, the vascular cambium produces more secondary phloem than xylem.
False, vascular cambium produces more secondary xylem than phloem
True or False: The annual ring on wood can indicated the climate during a tree’s liftetime.
True
What are vascular rays?
Vascular rays are radial strands of parenchyma cells that function in lateral conduction of nutrients and water. Can be xylem rays or phloem rays
Whys is spring wood light coloured?
Relatively large vessel elements of secondary xylem produced
Why is summer wood dark coloured?
Fewer, smaller vessel elements in proportion to tracheids and fibers
______ are protrusions of adjacent parenchyma cells into conducting cells of xylem.
Tyloses
What is the older, darker wood in the centre?
Heartwood
What is the lighter, still-functioning xylem closest to cambium wood?
Sapwood
What is the function of tyloses?
Prevent conduction of water
______ is the wood of conifers that has no fibres or vessel elements.
Softwood
The wood of dicot trees is know as ______.
Hardwood
What are resin canals?
Tube-like canals scattered throughout xylem and other tissues
Where are resin canals common?
Common in conifers and in some tropical flowering plants
______ is all tissues outside the vascular cambium, including secondary phloem
Bark
True or False: Mature bark may consist of alternating layers of crushed phloem and cork.
True
The ducts found mostly in phloem that have latex-secreting cells is known as ______.
Laticifers
Laticifers are commonly found in what 3 items?
Rubber, chicle (chewing gum), morphine
True or False: Monocots stems have neither a vascular cambium nor a cork cambium.
True
True or False: Monocots produce secondary vascular tissues or cork.
False, They produce no secondary vascular tissues or cork
True or False: In a typical monocot vascular bundle,
there are two large vessels with several small vessel.
True
In monocot stems, the vascular bundle is surrounded by ______ of ______ cells.
sheath, sclerenchyma
______ are horizontal stems that grow below-ground and have long to short internodes commonly found in irises, some grasses, and ferns.
Rhizomes
______ are horizontal stems that grow above ground and have long internodes commonly found in strawberries.
Runners
What are stolons?
A specialized stem produced beneath the surface of the ground and tend to grow in different directions commonly found in potatoes
______ are swollen, fleshy underground stems that store food in potatoes.
Tubers
______ are large buds surrounded by numerous fleshy leaves, with a small stem at lower end that store food commonly found in onions, lilies, hyacinths, tulips.
Bulbs
______ resemble bulbs, but composed almost entirely of stem tissue, with papery leaves.
Corm
What are cladophylls?
Flattened, leaf-like stems
commonly found in greenbriars, some orchids, prickly pear cactus
True or False: In a living tree, 50% of the wood weight comes from water content.
True
What percents of the dry part of wood are composed of cellulose and lignin.
60-75% cellulose and 15-25% lignin
______ cut boards show annual rings in the side view.
Radially
______ cut boards are cut perpendicular to rays and show annual rings as irregular bands of light and dark streaks.
Tangentially
