Bio 121- Evolution, adaptations and classification of plants

terms and defs

Adventitious

describes an organ that grows in an unusual place, such as a roots growing from the side of a stem

Antheridium

male gametangium

Archegonium

female gametangium

Capsule

case of the sporangium in mosses

Charophyte

other term for green algae; considered the closest relative of land plants

club mosses

earliest group of seedless vascular plants

Diplontic

diploid stage is the dominant stage

Embryophyte

other name for land plant; embryo is protected and nourished by the sporophyte

Extant

still-living species

Extinct

no-longer-existing species

Fern

seedless vascular plant that produces large fronds; the most advanced group of seedless vascular plants

Gametangium

structure on the gametophyte in which gametes are produced

Gemma

plural, gemmae) leaf fragment that spreads for asexual reproduction

Haplodiplodontic

haploid and diploid stages alternate

Haplontic

haploid stage is the dominant stage

Heterosporous

produces two types of spores

Homosporous

produces one type of spore

Hornworts

group of non-vascular plants in which stomata appear

Horsetail

seedless vascular plant characterized by joints

Lignin

complex polymer impermeable to water

Liverworts

most primitive group of the non-vascular plants

Lycophyte

club moss

Megaphyll

larger leaves with a pattern of branching veins

Megaspore

female spore

Microphyll

small size and simple vascular system with a single unbranched vein

Microspore

male spore

Mosses

group of bryophytes in which a primitive conductive system appears

non-vascular plant

plant that lacks vascular tissue, which is formed of specialized cells for the transport of water and nutrients

peat moss

Sphagnum

Peristome

tissue that surrounds the opening of the capsule and allows periodic release of spores

Phloem

tissue responsible for transport of sugars, proteins, and other solutes

Protonema

tangle of single-celled filaments that forms from the haploid spore

Rhizoids

thin filaments that anchor the plant to the substrate

seedless vascular plant

plant that does not produce seeds

Seta

stalk that supports the capsule in mosses

Sporocyte

diploid cell that produces spores by meiosis

Sporophyll

leaf modified structurally to bear sporangia

Sporopollenin

tough polymer surrounding the spore

Streptophytes

group that includes green algae and land plants

Strobili

cone-like structures that contain the sporangia

Tracheophyte

vascular plant

vascular plant

plant containing a network of cells that conducts water and solutes through the organism

Vein

bundle of vascular tissue made of xylem and phloem

whisk fern

seedless vascular plant that lost roots and leaves by reduction

Xylem

tissue responsible for long-distance transport of water and nutrients

Anther

sac-like structure at the tip of the stamen in which pollen grains are produced

Anthophyta

phylum to which angiosperms belong

Barcoding

molecular biology technique in which one or more short gene sequences taken from a well-characterized portion of the genome is used to identify a species

basal angiosperms

a group of plants that probably branched off before the separation of monocots and eudicots

Calyx

whorl of sepals

Carpel

single unit of the pistil

Conifer

dominant phylum of gymnosperms with the greatest variety of trees

Corolla

collection of petals

Cotyledon

primitive leaf that develops in the zygote; monocots have one cotyledon, and dicots have two cotyledons

Crop

cultivated plant

Cycad

gymnosperm that grows in tropical climates and resembles a palm tree; member of the phylum Cycadophyta

Dicot

(also, eudicot) related group of angiosperms whose embryos possess two cotyledons

Dioecious

describes a species in which the male and female reproductive organs are carried on separate specimens

Filament

thin stalk that links the anther to the base of the flower

Flower

underlinebranchesend underline specialized for reproduction found in some seed-bearing plants, containing either specialized male or female organs or both male and female organs

Fruit

thickened tissue derived from ovary wall that protects the embryo after fertilization and facilitates seed dispersal

Ginkgophyte

gymnosperm with one extant species, the Ginkgo biloba: a tree with fan-shaped leaves

Gnetophyte

gymnosperm shrub with varied morphological features that produces vessel elements in its woody tissues; the phylum includes the genera Ephedra, Gnetum, and Welwitschia

Gymnosperm

seed plant with naked seeds (seeds exposed on modified leaves or in cones)

Gynoecium

(also, carpel) structure that constitutes the female reproductive organ

heirloom seed

seed from a plant that was grown historically, but has not been used in modern agriculture on a large scale

Herbaceous

grass-like plant noticeable by the absence of woody tissue

Herbivory

consumption of plants by insects and other animals

Integument

layer of sporophyte tissue that surrounds the megasporangium, and later, the embryo

Megasporocyte

megaspore mother cell; larger spore that germinates into a female gametophyte in a heterosporous plant

Microsporocyte

smaller spore that produces a male gametophyte in a heterosporous plant

Monocot

related group of angiosperms that produce embryos with one cotyledon and pollen with a single ridge

Monoecious

describes a species in which the male and female reproductive organs are on the same plant

Nectar

liquid rich in sugars produced by flowers to attract animal pollinators

Ovary

chamber that contains and protects the ovule or female megasporangium

ovulate cone

cone containing two ovules per scale

Ovule

female gametophyte

paraphyletic group

not all descendants of a single common ancestor are included in the group

Perianth

part of the plant consisting of the calyx (sepals) and corolla (petals)

Petal

modified leaf interior to the sepals; colorful petals attract animal pollinators

Pistil

fused group of carpels

pollen grain

structure containing the male gametophyte of the plant

pollen tube

extension from the pollen grain that delivers sperm to the egg cell

Pollination

transfer of pollen from the anther to the stigma

Progymnosperm

transitional group of plants that resembled conifers because they produced wood, yet still reproduced like ferns

Seed

structure containing the embryo, storage tissue, and protective coat

Sepal

modified leaf that encloses the bud; outermost structure of a flower

Spermatophyte

seed plant; from the Greek sperm (seed) and phyte (plant)

Stamen

structure that contains the male reproductive organs

Stigma

uppermost structure of the carpel where pollen is deposited

Strobilus

plant structure with a tight arrangement of sporophylls around a central stalk, as seen in cones or flowers; the male strobilus produces pollen, and the female strobilus produces eggs

Style

long, thin structure that links the stigma to the ovary