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