Lab 5 Flashcards
anemophilous
plants that have evolved specific adaptations to maximize pollen dispersal by wind; flowers lack showy petals or strong fragrances, their pollen grains are lightweight and often produced in abundance, increasing the chances of successful pollination over long distances
entomophilous
plants that have evolved to attract insects such as bees, butterflies, and beetles to transfer pollen between flowers; flowers display vibrant colors, patterns and fragrances to lure pollinators; they may offer nectar as a reward
flower
reproductive structures of angiosperms; they consist of four main parts: sepals, petals, stamens, and pistils; they vary in size, shape, color, and scent, reflecting adaptations to their specific pollinators and environmental conditions
actinomorphic flower/polysymmetrical flower
flowers that exhibit radial symmetry; this symmetry allows pollinators to approach the flower from any direction
ex. daisy family
zygomorphic flower/monosymmetrical flower
flowers that display bilateral symmetry, meaning they can only be divided into two equal halves by a single plane; it corresponds to specialized pollination mechanisms, where specific pollinators are guided towards the flower’s reproductive structures
ex. orchids
floral formula
a shorthand notation used to represent the structure of a flower; includes information about the number and arrangement of floral parts, their fusion, and other important characteristics
floral diagram
graphical representation of a flower’s structure, depicting the arrangement and relationships of its floral parts; provides a visual summary of important floral characteristics, such as the arrangement of sepals, petals, stamens, and pistils
receptacle
enlarged tip of a flower’s stem where all the floral organs are attached; provides support and attachment for the sepals, petals, stamens, and pistils, serving as a central hub for the reproductive structures of the flower
pedicel
the stalk that supports the flower, attaching it to the main stem or branch of the plant; plays a crucial role in positioning the flower to optimize exposure to pollinators, ensuring successful pollination
perianth
collective term for the outer floral whorl, consisting of the sepals and petals; protect the developing flower bud and may also play a role in attracting pollinators through color, scent, or other visual cues
sepal
the outermost whorl of the flower, typically green and leaf-like in appearance; encloses and protects the bud before it opens and provides structural support to the flower
petal
the colorful, often fragrant parts of the flower, located inside the sepal; attract pollinators by providing visual cues such as color and pattern, as well as olfactory cues through their fragrance
perigon
the outer floral whorl when the sepals and petals are similar in appearance and not clearly differentiated
tepal
undifferentiated floral parts that resemble both sepals and petals
nectary
glandular organ found within the flower that produces nectar, a sugary liquid; nectar serves as a reward for pollinators, attracting them to the flower and encouraging them to transfer pollen between flowers
androecium
the male reproductive organ of the flower, comprising one or more stamens; produces and releases pollen, which contains the male gametes
stamen
the male reproductive organ of the flower, consisting of an anther and a filament; responsible for producing and releasing pollen, which contains the male gametes required for fertilization
anther
the pollen-producing structure located at the tip of the stamen; contains pollen sacs where pollen grains are produced through the process of meiosis, and it releases pollen when mature
connective (in stamen)
the tissue that connects the two lobes of the anther; plays a structural role in supporting the anther and facilitating pollen release during pollination
filament (in stamen)
a stalk that supports the anther, positioning it for optimal pollen dispersal; provides structural support to the anther
theca
the two lobes of the anther where pollen is produced; each lobe contains pollen sacs (microsporangia) where microsporocytes undergo meiosis to produce pollen grains
tapetum
a layer of nutritive tissue surrounding the sporogenous cells within the anther; provides nutrients to developing pollen grains and plays a crucial role in their maturation and release
endothecium
the inner layer of cells within the anther wall; helps to facilitate pollen release when the anther splits open
microspore
spores produced by microsporocytes within the microsporangia of the anther; each microspore produces a pollen grain
megaspore
large spores produced by megasporocytes within the ovule; they give rise to the embryo sac, which develops within the ovule and contains the egg cell
gametophyte
the haploid phase of the plant life cycle; the male gametophyte is produced within the pollen grain, while the female gametophyte develops within the ovule
pollen
male gametophyte of seed plants, produced by the anthers of flowers; consists of microscopic grains containing the male gametes
exine
tough outer layer of the pollen grain, composed primarily of sporopollenin; provides protection for the delicate contents of the pollen grain and may have sculptural features that aid in pollen dispersal
intine
inner layer of the pollen grain wall, located beneath the exine; composed of cellulose and other organic materials; involved in pollen tube germination and growth during pollination
vegetative cell
one of the cells within the pollen grain, responsible for forming the pollen tube during pollination; provides nutrients and structural support to the growing pollen tube as it penetrates the stigma and style of the pistil
sperm cell
male gametes contained within the pollen grain; they are released from the pollen grain and travel down the pollen tube to reach the ovule, where they fertilize the egg cell to initiate seed development
gynoecium
female reproductive organ of the flower, comprising one or more pistils; produces and nurtures the female gametes (egg cells) and facilitate their fertilization by pollen grains
pistil
female reproductive organ of the flower, consisting of three main parts: the stigma, style, and ovary; receives pollen, supports PT growth, and houses the ovules, where fertilization occurs
superior pistil
positioned above the attachment point of the other floral organs, such as sepals and petals; may protrude from the flower’s receptacle or be completely enclosed within the floral tube
inferior pistil
positioned below the attachment point of the other floral organs, often within a floral tube; may be partially or fully enclosed by the receptacle
ovary
enlarged basal portion of the pistil, located at the base of the flower; contains one or more ovules, which are the structures that develop into seeds after fertilization
placenta
tissue within the ovary where ovules are attached; provides support and nutrients to the developing ovules and seeds
ovule
structures within the ovary that contain the embryo sac, surrounded by integuments; attached to the placenta within the ovary by a structure called the funicle
ortotropous ovule
straight in its orientation on the placenta; the funicle, chalaza and micropyle lie in one straight line
anatropous ovule
body of the ovule is inverted and is turned at an angle of so that the micropyle and the funicle happen to lie next to each other
funicle
stalk-like structure that attaches the ovule to the placenta within the ovary; transports nutrients and water to the developing ovule and provides support during seed maturation
chalaza
the basal part of the ovule where the integuments converge; point of attachment for the funicle; provides support and protection to the developing embryo sac and ovule contents
integument
layers of tissue that surround the nucellus in the ovule, forming the seed coat after fertilization; protect the developing embryo sac and seed from mechanical damage or pathogens
micropyle
small opening in the integuments through which the pollen tube enters during fertilization
nucellus
central tissue within the ovule, containing the embryo sac and surrounding tissues; site of megasporogenesis
embryo sac
female gametophyte within the ovule, containing the egg cell and other supporting cells; develops from a megaspore
style
long, slender stalk that connects the stigma and the ovary
transmitting tissue
specialized tissue within the style that provides nutrients and support to the growing PT and guides it towards the ovary
stigma
receptive surface located at the top of the style in the pistil; covered with sticky or feathery structures that capture pollen grains during pollination
stigmatoid tissue
any specialized tissue on the stigma’s surface that aids in pollen capture and recognition; may include hairs, papillae, or other structures that enhance pollen adhesion and germination
