Chapter 7 Leaves Flashcards
leaf
(leef) a flattened, usually photosynthetic structure arranged in various ways on a stem
primordium
(pry-mord′ee-um) an organ or structure (e.g., leaf, bud) at its earliest stage of development
petiole
(pet′ee-ohl) the stalk of a leaf
blade
(blayd) the conspicuous flattened part of a leaf (also called lamina) or seaweed
sessile
(sess′uhl) without petiole or pedicel; attached directly by the base
deciduous
(duh-sij′yu-wuss) shedding leaves annually
simple leaf
(sim′pul leef) a leaf with the blade undivided into leaflets
compound leaf
(kom′pownd leef) a leaf whose blade is divided into distinct leaflets
pinnately compound; pinnately veined
(pin′ayt-lee kom′pownd; pin′ayt-lee vaynd) having leaflets or veins on both sides of a common axis (e.g., rachis, midrib) to which they are attached
rachis
(ray′kiss) the axis of a pinnately compound leaf or frond extending between the lowermost leaflets or pinnae and the terminal leaflet or pinna (corresponds with the midrib of a simple leaf)
palmately compound; palmately veined
(pahl′mayt-lee kom′pownd; pahl′-mayt-lee vaynd) having leaflets or principal veins radiating out from a common point
stoma
(pl. stomata) (stoh′muh; pl. stoh′mah-tuh) a minute pore or opening in the epidermis of leaves, herbaceous stems, and the sporophytes of hornworts (Anthoceros); it is flanked by two guard cells that regulate its opening and closing and thus regulate gas exchange and transpiration
transpiration
(trans-puh-ray′shun) loss of water in vapor form; most transpiration takes place through the stomata
guttation
(guh-tay′shun) the exudation from leaves of water in liquid form due to root pressure
node
(nohd) region of a stem where one or more leaves are attached
internode
(in′tur-nohd) a stem region between nodes
pinnately compound; pinnately veined
(pin′ayt-lee kom′pownd; pin′ayt-lee vaynd) having leaflets or veins on both sides of a common axis (e.g., rachis, midrib) to which they are attached
palmately compound; palmately veined
(pahl′mayt-lee kom′pownd; pahl′-mayt-lee vaynd) having leaflets or principal veins radiating out from a common point
midrib
(mid′rib) the central (main) vein of a pinnately veined leaf or leaflet
midvein
(mid′vayn) primary region of vascular tissue, usually spanning the center of a leaf
cuticle
(kyut′i-kul) a waxy or fatty layer of varying thickness on the outer walls of epidermal cells
cutin
(kyu′tin) the waxy or fatty substance of which a cuticle is composed
mesophyll
(mez′uh-fil) parenchyma (chlorenchyma) tissue between the upper and lower epidermis of a leaf
palisade mesophyll
(pal-uh-sayd′ mez′uh-fil) mesophyll having one or more relatively uniform rows of tightly packed, elongate, columnar parenchyma (chlorenchyma) cells beneath the upper epidermis of a leaf
spongy mesophyll
(spun′jee mez′uh-fil) mesophyll having loosely arranged cells and numerous air spaces; it is generally confined to the lower part of the interior of a leaf just above the lower epidermis
vein
(vayn) a term applied to any of the vascular bundles that form a branching network within leaves
bundle sheath
(bun′dul sheeth) the parenchyma and/or sclerenchyma cells surrounding a vascular bundle
epiphyte
An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes.
pitcher plants
Pitcher plants are several different carnivorous plants which have modified leaves known as pitfall traps—a prey-trapping mechanism featuring a deep cavity filled with digestive liquid. The traps of what are considered to be “true” pitcher plants are formed by specialized leaves
sundews
Drosera, which is commonly known as the sundews, is one of the largest genera of carnivorous plants, with at least 194 species. These members of the family Droseraceae lure, capture, and digest insects using stalked mucilaginous glands covering their leaf surfaces.
abscission
(ab-sizh′un) the separation of leaves, flowers, and fruits from plants after the formation of an abscission zone at the base of their petioles, peduncles, and pedicels
Young leaves are produced by leaf ______.
primordia
Most dicot leaves maximize their photosynthetic capacity by having a flattened leaf _______.
Blade
Petiole
In botany, the petiole is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules.
stipules
a small leaflike appendage to a leaf, typically borne in pairs at the base of the leaf stalk.
Sessile leaves
sessile - a leaf whose blade is attached directly to the stem, lacking a petiole. clasping (or amplexicaul) - a sessile leaf with free bases partly or entirely surrounding the stem.
petiole
the stalk that joins a leaf to a stem; leafstalk.
The flattened portion of a leaf is called a(n)…
blade, lamina, or leaf blade
All of the following that happen in the stomata on a leaf surface.
Carbon dioxide diffuses into the leaves where it can be taken up and used for photosynthesis.
Water vapor evaporating from the interior cell surfaces diffuses out into the atmosphere.
The region where a leaf is attached to a stem is called a(n) ______.
Node
Transpiration
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost by transpiration and guttation.
palisade mesophyll
packed, barrel-shaped parenchyma cells that are typically in two layers
spongy mesophyll
loosely arranged parenchyma cells with lots of air space in between
phyllotaxy
arrangement of leaves on a stem
internode
region between leaf attachments on a stem
mesophyll
the inner tissue (parenchyma) of a leaf, containing many chloroplasts.
All that happen through stomata.
Water vapors exits the leaves.
Carbon dioxide enters leaves by diffusion.
Which mesophyll layer consists of tightly packed, barrel-shaped cells?
Palisade mesophyll
The mesophyll encompasses all the tissues between the lower and upper _____ of a leaf.
Epidermis
All of the following that are functions that veins carry out in the leaf.
Transport sugars wherever they are needed
Transport water up from the roots and stems
The tissue between the lower and upper epidermis of a leaf is called _____
mesophyll
Very large leaves produced in a region of a plant that receives little sunlight are called _____ shade leaves
A leaf vein is a vascular _____
Bundle
Which of these are adaptations of leaves to an arid environment?
Succulent, water-retaining leaves
Sunken stomata
Dense, hairy coverings
The mesophyll in the leaves of submerged aquatic plants is not organized into distinct layers, and it has larger than normal ______.
air spaces
Shade leaves
Shade leaves generally contain a greater mass of chlorophyll and are darker green in colour. In shade leaves, the chloroplasts move within the cells to take up a position where they will absorb the maximum light without shading other chloroplasts below them.
Sun leaves
Sun leaves become thicker than shade leaves because they have a thicker cuticle and longer palisade cells, and sometimes several layers of palisade cells. The larger shade leaves provide a larger area for absorbing light energy for photosynthesis in a place where light levels are low.
There are many types of spiny structures that can grow on plants. Which one of these is a modified leaf?
Spine
There are many types of spiny structures that can grow on plants. Which one of these is a modified leaf?
Spine
Plants that have sunken stomata, succulent leaves, and hairy coverings are likely native to what kind of environment?
Arid
Succulent leaves
By definition, succulent plants are drought-resistant plants in which the leaves, stem, or roots have become more than usually fleshy by the development of water-storing tissue.
What are some characteristics of leaves on plants that live submerged in water?
They have significantly less xylem than phloem.
Large air spaces are found in the mesophyll.
Mesophyll is not differentiated into distinct layers.
When Dischidia plants in Australia make their modified flower-pot leaves, what kind of creature typically takes up residence in there, bringing in soil and nitrogen-rich wastes?
Ants
spines
modified leaves in cacti and other desert plants
thorns
modified stems on many species of tree such as Acacia
prickles
outgrowths of the epidermis or cortex along the stem of a rose or raspberry
Window leaves
Window leaves have transparent tips that allow light to penetrate for photosynthesis. Shade leaves are large leaves that grow above photosynthetic leaves that are in direct sunlight. This reduces light intensity and prevents the photosynthetic leaves from UV radiation damage. Common in Succulent plants
plantlets
: a small or young plant.
Brightly colored leaves that surround an inconspicuous true flower are called _____
bracts
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture.
All insect-trapping plants are native to areas that are severely limited in what nutrient?
Nitrogen
What pigments make a leaf turn from green to some other bright color at the end of its life cycle?
xanthophylls
anthocyanins
carotenes
Insect trapping leaves
Flypaper traps can be active or passive and rely on sticky mucilage, either directly on the leaf surface (butterworts) or on gland-tipped hairs (sundews), to capture prey. Snap traps, such as those of the Venus flytrap (Dionaea muscipula), use rapid leaf movements to actively ensnare insects.
Abscission
Abscission is the shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower, or seed. In zoology, abscission is the intentional shedding of a body part, such as the shedding of a claw, husk, or the autotomy of a tail to evade a predator.
What are some of the ways that leaves from plants are put to use by humans?
Dyes
Shade from tree leaves can reduce home cooling costs
Food
Cordage
anthocyanins
Anthocyanins (an-tho-SY-uh-nins) are a group of deep red, purple and blue pigments found in plants. They’re part of a larger category of plant-based chemicals called flavonoids. Flavonoids are abundant in all parts of plants: fruits, seeds, shoots, flowers and leaves.
carotenes
Carotene is a fat-soluble precursor of vitamin A that exists in green and yellow vegetables.
xanthophylls
Xanthophylls are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes. The name is from Greek xanthos and phyllon, due to their formation of the yellow band seen in early chromatography of leaf pigments.
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying.
Which of these is true about cocaine?
Andean natives chew the leaves from which cocaine is extracted for their medicinal properties.
It is illegal in the United States because of its narcotic use.
It is derived from leaves of the coca plant.
