Lecture Flashcards
– the broad part of the leaf where most of the photosynthesis happens and where the leaf veins can be found; contains the microscopic stomata for gas exchange in leaves
▪ lamina (leaf blade)
– the stalk that supports a leaf in a plant and attaches it to the stem
▪ petiole/leaf stalk
– two small flaps of tissue at the base of the petiole; protects the apical meristem while the leaf is young and small; when these are large enough, they have the capability to contribute a significant amount of photosynthesis
stipule
– the protruding part of the leaf
▪ leaf apex
– the perimeter of the leaf between the apex and base
▪ margin
– the part of the lamina that is attached to the petiole of the leaf
▪ base
– the angle formed by the attachment of a leaf to the stem o monocots
▪ leaf axil
– the basal part of a grass leaf that encircles the stem
▪ leaf sheath
– the expanded part of the monocot leaf which is usually uniform in thickness when midrib is absent
▪ leaf lamina
- a tissue outgrowth at the juncture between the blade and the sheath, the specialized basal region of the leaf that wraps around the stem
▪ ligule
– the earlike lobes or appendages which are borne, one on either side, at the base of the leaf blade
▪ auricle
– leaves with undivided blade or lamina
Simple leaves
– has leaflets that occur in succession along a rachis
Pinnately compound
– has leaflets radiating outwards from the end of the petiole, like fingers off the palm of a hand
Palmately compound
Compare monocot and dicot in terms of mesophyll cells
Monocot- single-layered
Dicot-two different mesophylls, i.e. palisade mesophyll and spongy mesophyll
Compare monocot and dicot in terms of Motor or Bulliform
Cells
Monocot- epidermal cells present in the upper surface of the monocot leaf; they large, empty and colorless, and present in the midvein
Dicot- absent
Compare monocot and dicot in terms of Intercellular spaces
Monocot- small due to the compact arrangement of mesophyll cells
Dicot- large due to the presence of loosely packed
mesophyll cells
Compare monocot and dicot in terms of Vascular bundles
Monocot- many small and large-sized vascular bundles present in a
parallel pattern
Dicot- generally large
Compare monocot and dicot in terms of Protoxylem - -
monocot- protoxylem elements are distinguishable as
protoxylem lacuna
dicot- do not show differentiation into protoxylem elements
Compare monocot and dicot in terms of Bundle sheath
- monocot leaves- single or double layer; colored cells due to the presence of chloroplasts -
- Dicot- generally single-layered; colorless cells
Compare monocot and dicot in terms of Stomata
Monocot- dumbbellshaped guard cells
Dicot- bean shaped guard cells
happens through the plant’s stomata; the water vapor from the leaves exits through the stomata of plants cooling the plant when the weather is very hot; this process also pulls the water molecules upwards, from the stem and roots and leaves then out of the stomata
- transpiration
happens at night when the stomata are close and when transpiration can not remove water from the plant like it does during the day
- guttation
– where most photosynthesis takes place
➢ Mesophyll
– composed of tightly packed parenchyma cells and may contain more than 80% of the leaf’s chloroplast
➢ Palisade mesophyll
– contains loosely arranged parenchyma cells resulting to an abundant air spaces in between them
➢ Spongy mesophyll
– these are parenchyma cells that contain chloroplasts, mainly found in leaves but are also found in herbaceous plant parts, green stems, and green roots.
➢ Chlorenchyma cells
- this is the normal shedding of an old leaf at the base of the petiole
Leaf abscission
plants that seasonally drop their leaves
- deciduous –
– it is where abscission occur; located at the base of the petiole of each leaf
- abscission zone
– these are leaves with lesser sun exposure, tend to be larger than their counterparts in the sun, and are much thinner
➢ shade leaves
– these are thick leathery leaves with fewer stomata of plants found in arid places
➢ fleshy leaves
– these are non-photosynthetic modified leaves that serve as storage and protection of an emerging bud
➢ scale leaves
- submerged leaves of plants that grow in water usually have considerably less xylem than phloem, and the mesophyll, which is not differentiated into palisade and spongy layers, has large air spaces
➢ aquatic leaves
– modified leaves that function for support and climbing by tightly curling around rigid objects
➢ tendrils
– leaves are reduced into these modification to further avoid plant desiccation in arid areas and these also function as protection from browsing animals
➢ spines
➢– contain large amounts of thin-walled parenchyma cells for water storage
storage leaves/succulent leaves
– new plants emerge from the margins of the leaf like what happens to Kalanchoe pinnata
➢ reproductive leaves
– these are found at the bases of flowers or flower stalks; these function as attractant to pollinators
➢ floral leaves (bracts)
➢ - these are found in pitcher plants, sundews, venus flytrap, and bladderworts; these are specialized leaves that function for acquiring the needed nutrients of plants through digesting insects that they trap
insect-trapping leaves
State three economic importance of leaves
- May serve as source of food.
- May serve as source of fiber.
- May serve as source of medicine.
the main function of ______ of plants is to transport water, minerals and nutrients to every inch of the plant body
vascular tissues
– water and minerals absorbed by roots are drawn upwards through this type of vascular tissue
o xylem
– sugar produced by photosynthesis is exported from leaves to other organs through this vascular tissue
o phloem
– wide, thin walled, hollow cells; dead at maturity (sclerenchyma
tissue); function for transport and support
- vessel elements
– narrower, tapered cells; have pits at ends that allow water transport
- tracheid
- it is a measure of where water wants to go into a plant; determines the direction of movement of water
Water Potential
True of false?
Solute Potential can either be positive or negative.
False. IT’S ALWAYS NEGATIVE
is the physical pressure on a solution
pressure potential
- results from the swelling of a plant cell against its cell wall
Turgor Pressure
- the extracellular pathway of cell wall
- substances move between cells trough the cell walls, which are connected
Apoplast Route
- during ______ elements and organic solutes are transferred between the xylem and phloem by extensive exchange processes
long-distance transport,
- water and solutes move through xylem and phloem by ____, the movement of a fluid driven by pressure
bulk flow
is the evaporation of water from leaves and other parts of the plant
- transpiration
▪ this upward push of xylem sap is called
root pressure
PULLING Xylem Sap can be explained by ____
Cohesion-tension Theory
water to water bonding is ___; water to non-water/other surface bonding is___
cohesion; adhesion
Explain the Mechanism for Stomatal Opening and Closing with the following keywords
- K+
- solute potential
- higher water potential to lower potential
- turgor pressure
K+ is pumped into guard cells by active transport.
- solute potential becomes negative.
- water moves from the higher water potential to lower potential entering the guard cells. - turgor pressure cause cells to bow out & creates open stoma.
Give the 3 Stimuli that Cause Stomatal Opening
- blue light receptors signal .
- depletion of carbon dioxide
- circadian rhythms-
- ____ causes stomatal closing during the day.; ____is a hormone produced in the roots to cause this response
environmental stress (heat/drought); absciscic acid
- phloem, carries phloem sap (contains carbohydrate) from a sugar source to a sugar
Phloem Sugar Transport
▪ _____an organ where sugar is being produced usually leaves
▪ ____An organ that consumes or stores sugar usually roots, growing stems, buds, and fruits
Sugar source; Sugar sink
Explain Pressure Flow: Mechanism of Translocation in Phloem with the following key words/phrases
- pressure at source
pressure in sink
water diffusion/translocation
pressure is created at source as sugar is produce
- pressure decreases in sink as sugar is used
- water diffuses into phloem from xylem due to decrease water potential & pushes the sugar from source to sink. this is known as translocation
– these are plants that flower only once; vegetative growth ceases at floral initiation e.g., grasses, small grains, corn
determinant
– these are plants that continue to grow vegetatively after floral initiation; flower for longer period of time e.g., beans, cotton, petunia
indeterminant
– borne singly on a stalk; solitary flowers
– arranged in multiples or clusters often called an inflorescences
a) simple flowers
b) compound flowers
– a common strategy employed by hermaphroditic angiosperms to reduce sexual interference between male (anthers) and female (stigma) function; differs from other such strategies (e.g., dichogamy) by supplying a spatial separation of the anthers and stigma
Herkogamy/hercogamy
- the production of male and female reproductive elements at different times by a hermaphroditic organism in order to ensure cross-fertilization
Dichogamy
– inability of pollen grains to fertilize flowers of the same plant or its close relatives; acts as a mechanism to ensure out breeding within some plant species, for example in the case of the s gene complex in brassicas
Self-incompatibility
- involves naturally occurring emasculation of the male gamete, thus preventing self-pollination in plant species; the growth of the pollen tube in the pistil or the germination of pollen grains is inhibited and this prevents the fertilization of the ovules from the pollen of the same flower
Male sterility
- the condition of an organism or species capable of producing only male or female gametes (sex cells) but never both; cross-pollination always occurs when the plants are unisexual and dioecious.
Dioecism
- the flowers of some plants have different lengths of stamens and styles so that self-pollination is not possible
Heterostyly
: a sugary solution produced in special flower glands called nectaries
nectar
: high in protein content some bettles and bees like to eat
pollen
cells which supports the embryo in the endosperm
suspensor,
Distinguish the EXTERNAL STRUCTURE between Phaseolus vulgaris and Ricinus communis
Phaseolus vulgaris- have hilum, micropyle, and raphe
Ricinus communis- has an external structure called the caruncle, which is a spongy outgrowth of the outer seed coat.
layer that contain proteins and fats but little or no starch.
the aleurone layer
The shoot apex, together with several rudimentary leaves, is ensheathed by a
coleoptile
The radicle is surrounded by the
coleorhiza
A relatively large part of the grass embryo is a very specialized, shield-shaped cotyledon called the
scutellum
the straightening of the hypocotyl raises the cotyledons and shoot apex toward the light is called
epigeal germination.
When the pea epicotyl straightens, the cotyledons remain below ground, and only the apex and first leaf are raised upward. This is called
hypogeal germination
inability to germinate because of reduced physiological activity
dormancy
A ____, the ripened ovary of a flower, is an important auxiliary structure in the sexual life cycle of angiosperms
fruit
Tissues other than the ovary wall that form part of a fruit, are referred to as ___
accessory
The tiny individual fruits, called ____ , are simple, dry fruits. They are embedded in an enlarged fleshy receptacle.
achenes
The legume or pod is the type of fruit found in nearly all members of what family???
the pea family (Fabaceae)
The _____ is the characteristic fruit of members of the mustard family (Brassicaceae).
silique
The _____ is the fruit of the grass family (Poaceae),
caryopsis or grain
The schizocarp is a fruit characteristic of ___ family which includes celery (Apium graveolens). The schizocarp consists of___carpels that split, when mature, along the midline into two one-seeded, indehiscent halves
carrot family (Apiaceae); two
typical ___ is a one-seeded, indehiscent dry fruit with a hard or stony pericarp (shell).
nut
Note that unshelled almonds (Prunus sp.), are really not nuts but fleshy fruits known as
drupes
True or false? Brazil nuts (Bertholleda excelsa) are BERRIES, not nuts, and the unshelled peanut (Arachis hypogaea) is really a SEED
FALSE. Brazil nuts (Bertholleda excelsa) are SEEDS, not nuts, and the unshelled peanut (Arachis hypogaea) is really a POD
A ____ is a fleshy type of fruit that is derived from a compound ovary.
berry
Lemons, oranges, limes, and grapefruits (all Citrus sps.) are a type of berry called a
hesperidium.
The fruits of watermelon (Citrullus vulgaris), cucumber, and squash–all members of the cucumber family (Cucurbitaceae)–are a kind of berry called a
pepo
Apples (Malus sp.) and pears (Pyrus sp.), both in the Rosaceae family, are examples of
pomes.
An _____ is formed from numerous carpels of one individual flower. These fruits are made up of many simple fruits attached to a fleshy receptacle.
aggregate fruit
A ____ is formed from individual ovaries of several flowers, all clumped together.
multiple fruit
Fruits that develop without fertilization are called __
parthenocarpic
TRUE OR FLASE?
there is no nutritional relationship between the fruit and the seeds within it
true
Common abiotic vectors for fruit and seed dispersal are
wind and water
food bodies
elaiosomes
the metabolic quirks of at least one species of animal have successfully defused each chemical defense originated by seeds and fruits. This is referred to as
coevolution.
In seeds of monocotyledonous plants, food is usually stored in _____. In grasses, such as corn, the single cotyledon-like structure _____ is a specialized organ that absorbs the nutrients from the endosperm.
endosperm; (scutellum)
- The first step in germination is the ___ of water
imbibition
- Dormancy is usually broken by providing the seed with ____
moisture, oxygen, and a favorable temperature
The ovary wall fleshy and containing one or more carpels and seeds:
Berry
a. Ovary wall with a hard rind:
b. Ovary wall with a leathery rind:
Pepo ; Hesperidium
Exocarp thin; mesocarp fleshy; endocarp stony; single seed and carpel:
Drupe
Outer portion of pericarp fleshy, inner portion papery, floral tube fleshy; several seeds and carpels:
Pome
a. Composed of one carpel
i. Splitting along two margins:
ii. Splitting along one margin:
Legume or Pod.
Follicle.
b. Composed of two or more carpels
i. Dehiscing in one of four different ways:
ii. Separating at maturity, leaving a persistent partition wall:
Capsule (poppy)
Silique (mustard)
Indehiscent fruit , Pericarp bearing a winglike growth:
Samara
Two or more carpels, united when immature, splitting apart at maturity:
Schizocarp
one-seeded, united to the pericarp all around:
Caryopsis or Grain
Fruit large, with thick, stony wall:
Nut
Fruit small, with thin wall:
Achene. (sunflower)
Fruits developing from one flower:
Aggregate fruit
Fruits formed from several flowers:
Multiple fruit
