Botany Practical #2
Pedicel
Flower stalk of an individual flower in an inflorescence
Hermaphroditic
Possessing both the male and the female reproductive organs plants with perfect flowers (apples, tulips)
receptacle
The base of a flower; the part of the stem that is the site of attachment of the floral organs.
stamens & carpels
are reproductive parts of the flower
many angiosperms are pollinated by?
bees and other insects
Each pistil is composed of one or more modified leaves called?
carpels
the endosperm consist of?
cells rich in proteins, fats, oils, & starch is absorbed by the embryo during development or seed germination
Pistil
central female organ of flower. it is generally bowling-pin shaped & located at center of flower
locules
chambers of the ovary that contain the ovules
androecium
collective term for stamens
simple pistil
composed of single carpel
compound pistil
composed of two or more carpels fused together
calyx and corolla
comprise the *perianth*
style
connective tissues between stigma & ovary
stamen
consists of anther (where pollen is produced) and filament (stalk)
ovary
contains ovules or embryo sacs
aggregate fruits
develop from single flowers that have several separate carpels such as strawberries & blackberries
simple fruits
develop from single ovaries & may be fleshy, such as cherries, or dry, such as legumes (beans & peas)
The fusion of the egg with 1 sperm & the polar nuclei cell with the second sperm nucleus is called ____ ____ & is unique to flowering plants
double fertilization
After double fertilization the zygote develops into the ____ , the endosperm nucleus develops into the endosperm tissue which provides nutrients for the embryo, while the other cells of the embryo sac degenerate and the ovule begins developing into a ____
embryo; seed
ray flowers
flowers arranged around the disk flowers
Pistillate
flowers containing only female parts
staminate
flowers containing only male parts
Animal-dispersed seeds
generally are produced in fleshy fruits (berries, grapes, cherries, apples) eaten by vertebrates
female reproductive structures are collectively referred to as the?
gynoecium
ovules in plants
immature seeds
water-dispersed seeds
include those from plants that grow near or in water & have seeds or fruit adapted for floating. rainfall is significant in seed dispersal of some species
wind-dispersed seeds
include those that are lightweight & buoyant in the air
tomato fruit
is a berry
in a rose you will see the visible parts of the sepals, petals, & stamens all arise from the rim of the hypanthium which is an example of a ____ flower
perigynous
What is centrally positioned at the center of the flower?
pistil
dioecious
plants with male flowers and female flowers on separate plants; maple, holly, salt brush
gynoecious
plants with only female flowers
Andromonoecious
plants with only male flowers
Monoecious
plants with separate male and female flowers on same plant; corn, squash and pine.
anthers
pollen-producing organs
A pollen tube grows through a ____ in the pollen cell wall & continues down the style toward the ovule in the ovary
pore
seed germination occurs when appropriate environmental conditions are ?
present
stigma
receives pollen, typically flattened & sticky
What are the reproductive structures of gymnosperms & angiosperms?
seeds
the ovules of a plant develop into
seeds
petals & sepals that look alike are often referred to as?
tepals
anthers & pistils are called?
the *essential* parts
Imbibition
the absorption of water --> the first step in the germination of most seeds. This hydration causes a seed to expand & rupture its coat
polar nuclei
2 nuclei, within the same cell, created from the mitotic division of the megaspore during angiosperm reproduction; unite in the ovule to form a fusion nucleus, which gives rise to endosperm when fertilized
Directed by a chemical attraction, the tip of the pollen tube enters the ovule & discharges ____ ____ ____ into the *embryo sac*. One sperm fertilizes the *egg*, producing a *zygote*, & triploid (3n) *endosperm* nucleus.
2 sperm cells
incomplete flower
A flower in which one or more of the four basic floral organs such as sepals, petals, stamens, or carpels are either absent or nonfunctional.
daisies, sunflowers, asters, black-eyed susans, dandelions, and many others belong to a very large family of flowering plants called the ____ , commonly called ____
Asteraceae; composites
pollination
The placement of pollen from the anther onto the stigma of the pistil by wind or animal vectors and is a prerequisite to fertilization.
Antipodals
The three haploid nuclei in the mature embryo sac of seed plants that are located at the chalazal end of the egg sac
examples of simple fruits
Tomatoes, peaches, beans, walnuts drupes, pomes, citrus fruits corn, oats
What does the pistil consist of?
a *stigma* at the tip that receives pollen and a *style* that leads to the *ovary*
hypanthium
a cuplike or tubular enlargement of the receptacle of a flower, loosely surrounding the gynoecium or united with it.
sepals & petals are known as?
accessory floral parts since these are not absolutely necessary for reproduction
calyx
all the sepals
stamens
male flower organ
actinomorphic (regular)
more than one dividing plane
zygomorphic (irregular)
one bilateral dividing plane
complete flower
one that has all 4 floral parts: • sepals • petals • stamens • carpels
What is the angiosperm flower composed of?
sepals, petals, stamens (androecium), and a carpel or carpels (gynoecium)
a pistil may be either ____ or ____
simple; compound
filament
stalk supporting anther
pedicel
stalk that supports the flower
Most flowers contain both what?
stamens and a pistil, although some species produce unisexual flowers
How have flowers contributed greatly to the success of angiosperms?
they enhance the efficiency of plant reproduction by attracting & rewarding pollen-carrying animals
Perfect flowers
those with both male & female reproductive structures
synergid
two cells that flank the egg cell and function in the attraction and guidance of the pollen tube to the embryo sac one of two small cells lying near the egg in the mature embryo sac of a flowering plant type of cell found in the ovule sac that secretes chemicals to guide the pollen tube towards the egg
ovules
unfertilized, immature seeds
When a pollen grain adheres to the stigma of the same species of plant, it absorbs?
water & swells
What is the primary pollinating agent for grasses & many trees? Because of this random dispersal, enormous quantities of pollen grains are released by the anthers of the flowers
wind
regardless of the position of the ovary, most angiosperms rely on ____ or ____ for pollination
wind; animals
sepals
• Leaflike parts that cover and protect the flower bud • outermost circle of protective leaflike structures • they are usually green and are collectively called the *calyx*
Function of Flowers
• Reproduction, beginning with pollination & fertilization • Advertisement & rewards to lure a pollinator • Horticultural uses • Aesthetic qualities (cut flowers & potted blooming plants) • Edible flowers & herbs • Plant identification
Dicots
• Two cotyledons • Flower parts in fours or fives or multiples of four or five • leaf veins form a net pattern • vascular bundles arranged in a ring
carpel
• a megasporophyll upon which ovules are produced • carpel encloses the ovules so that seeds are produced within a protective layer that matures to form a fruit • The female reproductive organ of a flower, consisting of the stigma, style, and ovary.
typical seed of an angiosperm consist of?
• a protective *seed coat* • a sporophyte *embryo* • a layer of nutritive tissue called the *endosperm*
perianth
• calyx + corolla • the outer, sterile whorls of a flower
perigynous
• centrally-positioned ovary with floral parts on a cup-shaped receptacle (hypanthium?) • having the stamens and other floral parts at the same level as the carpels • where floral whorls are attached around or on the side of the gynoecium
ovary
• composed of 1 or more modified leaves known as carpels • In flowers, the portion of a carpel in which the egg-containing ovules develop. • A flower structure that encloses and protects ovules and seeds as they develop.
the embryo consist of?
• cotyledons • epicotyl • hypocotyl • radicle
multiple fruits
• develop from groups of separate flowers clustered tightly, such as pineapples • develop from a group of flowers called an inflorescence
petals
• generally form a whorl inside of the calyx and are collectively termed corolla • often brightly colored and may secrete aromatic substances and nectar to attract pollinating insects
Epigynous
• inferior ovary • flower parts above the ovary • where floral whorls are attached above or on top of the gynoecium
monocots
• one cotyledon • flower parts in threes or multiples of threes • leaf veins parallel • vascular bundles scattered
fruits are classified on the basis of development & mature structure into 3 principal groups:
• simple • aggregate • multiple
hypogynous
• superior ovary • flower parts below the ovary • where floral whorls are attached underneath the relative position of the gynoecium • Floral organization in which the sepals, petals, and stamens are attached to the receptacle below the ovary
gynoecium
• the female part of a flower, consisting of one or more carpels. • the group of structures that constitute the female reproductive organ; also called the pistil
Angiosperm vs. Gymnosperm
• the seeds of gymnosperms develop on the exposed surface of the scales of cones, whereas the seeds of angiosperms usually develop within a fruit produced from the ovary of a flower • Angiosperms, also called flowering plants, have seeds that are enclosed within an ovary (usually a fruit), while gymnosperms have no flowers or fruits, and have unenclosed or "naked" seeds on the surface of scales or leaves. Gymnosperm seeds are often configured as cones.
imperfect flowers
• unisexual • Flowers with either stamens or carpels, but not both