Lab 30: Angiosperms

pollen grains

each of the microscopic particles, typically single cells, of which pollen is composed. Pollen grains have a tough coat that has a form characteristic of the plant producing it.

stem apical meristem

is found at the apices, or tips of the plant, both the tip of the shoot and the root and is a region of actively dividing cells.

radicle

is the embryonic root of the plant, and grows downward in the soil

epicotyl

is the embryonic shoot above the cotyledons that develops into leaves

sperm nuclei

one sperm fertilizes the egg and the other forms a tripod with the other two polar bodies

double-fertilization

one sperm nucleus fuses with the egg to form the diploid zygote and the other sperm fuses with the two polar nuclei to form a triploid nucleus

integument

ovules have two coverings called integuments

proembryo

to denote the series of cells that are formed after fertilization within the ovule of a flowering plant, before formation of the embryo.

pericarp

which is the tissue that develops from the ovary wall of the flower and surrounds the seeds.

petal

whorls of structures located inside and usually above the sepals; may be large and pigmented or inconspicuous

generative cells

A cell of the male gametophyte or pollen grain in seed plants that gives rise to the sperm cells.

pome

A fleshy (false) fruit, formed from an inferior ovary, in which the receptacle or hypanthium has enlarged to enclose the true fruit.

pedicel

the stalk bearing a single flower of an inflorescence.

micropyle

A minute opening in the ovule of a seed plant through which the pollen tube usually enters

fertilization

A process in sexual reproduction that involves the union of male (sperm) and female (ovum) gametes (each with a single, haploid set of chromosomes) to produce a diploid zygote

seed coat

A seed is an embryonic plant enclosed in a protective outer covering. The formation of the seed is part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants.

coleorhizae

A sheath-like structure found in a plant seed that connects the coleoptile to the primary root and acts as a protective covering enclosing the plumule and radicle.

egg

An organic vessel where an embryo develops, and one in which the female of an animal species lay as a means of reproduction

heart-shaped stage

Differential division of the globular stage produces bilateral symmetry and two cotyledons forming the heart shaped embryo. the enlarging cotyledons store digested food from the endosperm. Tissue differentiation begins and the root and shoot meristems soon appear

mesocarp

Fruit anatomy is the internal structure of fruits. Fruits are the mature ovary or ovaries of one or more flowers. In fleshy fruits, the outer layer (which is often edible) is the pericarp, which is the tissue that develops from the ovary wall of the flower and surrounds the seeds. Between endocarp and exocarp

synergic nuclei

One of two small, short-lived nuclei lying near the egg in the mature embryo sac of a flowering plant.

anther

Pollen-bearing structure in the stamen (male organ) of the flower usually located on top of the filament of the stamen.

regular flowers

Sexual reproductive structure of plants, especially of angiosperms (flowering plants)

placental tissue

The outer layer cells turn into a form of epithelium, almost like skin cells, that function to transport gases, nutrients, and wastes.

radially symmetrical

Symmetrical arrangement of parts of an organism around a single main axis, so that the organism can be divided into similar halves by any plane that contains the main axis.

carpel

The carpels are female reproductive structures that produce egg cells and protect a developing baby plant, or embryo. The three main parts of a carpel are the stigma, style, and ovary.

suspensor

The chain of cells that anchors a plant embryo in the surrounding gametophyte tissue. Attaches the embryo to the embryo sac and extends to push the embryo into the endosperm

megagametogenesis

The female gametophyte that arises from a megaspore of a heterosporous plant. In angiosperms, the megagametophyte is the embryo sac.

megasporogenesis

The formation of megaspores inside the ovules of seed plants. A diploid cell in the ovule, called a megasporocyte or a megaspore mother cell, undergoes meiosis and gives rise to four haploid megaspores.

endocarp

The inner layer of the pericarp of a fruit, which can be soft, such as the pulp of an orange, or hard, such as the stone of a peach.

stigma

The top of the pistil is called the stigma, and is often sticky.

polar nuclei

Two haploid nuclei in the centre of the embryo sac of flowering plants. These nuclei fuse with a male gamete nucleus to form a triploid endosperm nucleus, which subsequently divides to form the endosperm.

caryopsis

a dry one-seeded fruit in which the ovary wall is united with the seed coat, typical of grasses and cereals.

ovary

a female reproductive organ in which ova or eggs are produced, present in humans and other vertebrates as a pair.

legume

a leguminous plant, especially one grown as a crop. a seed, pod, or other edible part of a leguminous plant used as food.

microspores

mother cells are formed within the pollen sacs of the anthers by mitosis; develop into pollen grains

meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

mitosis

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

samara

a winged nut or achene containing one seed, as in ash and maple.

hilum

an adjacent elliptical area at which the ovule was attached to the ovary

cotyledon

an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed.

receptacle

an enlarged area at the apex of a stem that bears the organs of a flower or the florets of a flower head.

basal cell

any cell situated at the base of a multilayered tissue, as at the lowest layer of the epidermis

microspore mother cell

are formed within the pollen sacs of the anthers by mitosis; the microspores they produce develop into pollen grains.

scutellum

can also refer to the equivalence of a thin cotyledon in monocots

globular stage

cell division of the pro embryo soon leads to the globular stage that is radially symmetrical and has little internal cellular organization

shoot

consist of stems including their appendages, the leaves and lateral buds, flowering stems and flower buds. The new growth from seed germination that grows upward is a shoot where leaves will develop.

filament

consists of a slender stalk found in stamen

berry

endocarp fleshy or slimy; ovary usually many seeded

peduncle

flower stalk

multiple fruit

fruit from carpels of many flowers fused together

drupe

fruit in which the outer layer of the ovary wall is a thin skin, the middle layer is thick and usually fleshy

bilaterally symmetrical

have mirror symmetry in the sagittal plane, which divides the body vertically into left and right halves, with one of each sense organ and limb pair on either side.

tube nucleus

he one of the two nuclei formed by mitotic division of a microspore during the formation of a pollen grain that is held to control subsequent growth of the pollen tube and that does not divide again

exocarp

he outermost layer of the pericarp of fruits; the skin or epicarp.

nut

in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall becomes increasingly hard as it matures, and where the seed remains unattached or free within the ovary wall.

zygote

is a eukaryotic cell formed by a fertilization event between two gametes.

seed

is a mature ovule that includes a seed coat, a food supply and an embryo.

fruit

is a mature, ripened ovary plus any associated tissues

embryo

is a multicellular diploid eukaryote in its earliest stage of development, from the time of fertilization through sexual reproduction until birth, hatching, or germination.

sporophyte

is a multicellular diploid generation found in plants and algae that undergo alternation of generations. It produces haploid spores that develop into a gametophyte.

root cap

is a section of tissue at the tip of a plant root

microsporangia

is a sporangium that produces spores that give rise to male gametophytes.

gametophyte

is a stage in the life cycle of plants and algae that undergo alternation of generations. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes.

endosperm

is a tissue produced inside the seeds of most of the flowering plants following fertilization.

achene

is a type of simple dry fruit

root apical meristem

is found at the apices, or tips of the plant, both the tip of the shoot and the root and is a region of actively dividing cells.

gynoecium

is the innermost whorl of (one or more) pistils in a flower and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium.

perianth

is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals).

germination

is the process by which a plant grows from a seed

microgametogenesis

is the process in plant reproduction where a microgametophyte develops in a pollen grain to the three-celled stage of its development. In flowering plants it occurs with a microspore mother cell inside the anther of the plant.

microsporogenesis

is the production of microspores within microsporangia of a flowers anther vs meiosis

sporogenesis

is the production of spores in biology. The term is also used to refer to the process of reproduction via spores.

hypocotyl

is the stem of a germinating seedling, found below the cotyledons (seed leaves) and above the radicle (root).

pollination

is the transfer of pollen to a receptive surface

shoot apical meristem

meristem at the apex of a root

antipodal cells

play a part in embryo nutrition in certain genera.

gametogenesis

production of gametes during meiosis

megaspore mother cell

r megasporocyte, is a diploid cell in plants in which meiosis will occur, resulting in the production of four megaspores, the spores that develop into female gametophytes.

vegetative structure

roots, stems and leaves

capsule

seeds released through pores or multiple seams

coleoptile

sheath enclosing shoot apical meristem and leaf primordia of grass embryos

generative nucleus

small, spindle shaped and off center. One of the two nuclei in an angiosperm pollen grain. It divides to produce two male gamete nuclei

flowers

sometimes known as a bloom or blossom, is the reproductive structure found in plants that are floral

style

structure found within the flower. It is a long, slender stalk that connects the stigma and the ovary.

irregular flowers

such as those of the violet or the pea, are often bilaterally symmetric. is generally distinguished by petals of unequal size or shape.

aggregate fruit

that develops from the merger of several ovaries that were separate in a single flower

torpedo stage

the cotyledons and root axis soon elongate to produce an elongate torpedo-stage embryo. Procambial tissue appears and it will later develop into vascular tissue

megagametophytes

the embryo sac

embryo sac

the entire haploid structure is called this and consists of only six to ten nuclei, one of which is an egg

megaspore

the larger meiospore produced in heterosporous plants, and develops into a female gametophyte

sepal

the lowermost or outermost whorls of structures which are leaflike and protect the developing flower

stamen

the male fertilizing organ of a flower, typically consisting of a pollen-containing anther and a filament.

mature embryo

the mature embryo has large, bent cotyledons on each side of the stem apical meristem. The radicle later forms the root, is differentiated towards the suspensor

ovule

the megagametophyte and its surrounding tissues

root

the part of a plant that attaches it to the ground or to a support, typically underground, conveying water and nourishment to the rest of the plant via numerous branches and fibers.

calyx

the sepals collectively