Bio Exam 2

Seed

embryo packaged with a supply of nutrients inside a protective coat

Homospory

produced one kind on spore

Heterospory

produces two kinds of spores

Microsporangia

________→ microspores (n) → pollen grains

archegonium

Megasporangia → megaspores → ________ → egg

Sporopollenin

protective polymer; makes up the pollen wall/pollen grain (holds pollen - male gametophyte)

Ovule

female gametophyte within ovary

Pollen grain

contains male gametophyte (pollen)

Pollination

transfer of pollen to part of a seed plant containing ovules (required for fertilization)

Germination

when pollen starts to grow into a pollen tube that is able to discharge sperm into female gametophyte (within ovule)

Gymnosperm

”naked seed”; gametophytes develop into cones;

Angiosperm

“contained seed”; gametophytes develop into flowers (mature into fruits); 90% of all plants

Conifer

”to carry cones” - cone bearing plants; heterosporous

Microsporophyll

male modified leaves that bear microsporangia; stamen

Megasporophyll

female modified leaves that bear megasporangia; carpels

Ovulate cone

more complex than pollen cones; megasporophylls → Megasporangium → megasporocyte → megaspore → female gametophyte → egg

Pollen cone

simpler structure than ovulate cones

Phylum Cycadophyta

”cycads”; large cones and palm-like leaves; flagellated sperm; thrived during Mesozoric era; most endangered of all plant groups (75% at risk)

Phylum Ginkgophyta

flagellated sperm; only one species - Ginkgo biloba (“maidentree tree”)

Phylum Gnetophyta

3 Genera: gnetum, ephedra. Welwitschia

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Welwitschia mirabilis: can live for thousands of ears; found only in deserts of SW Africa; strap-like leaves (largest leaves known)

Phylum Coniferophyta

largest gymnosperm phyla (600 species)

Flower

specialized shoots with up to 4 sets of modified leaves, bearing structures for sexual reproduction

Sepals

helps enclose/protect the flower bud before it opens (usually green); sterile floral organ

Petals

colorful parts that advertise the flower to insects and other pollinators; not in wind-pollinating plants

Stamens

pollen-producing reproductive organ

Filaments

stalk

Anthers

terminal sac where pollen grains form

Carpels

ovule-producing reproductive organ

Stigma

sticky part of carpel that receives pollen

Style

stalk

Ovary

where egg-containing ovules develop;If fertilized → seed

Pistil

single carpel or group of fused carpels

Fruit

mature ovary of a flower; protects dormant seeds and often aids in dispersal

Pericarp

formed from wall of fruit, surrounds the seed

Embryo sac

female gametophyte of angiosperm

Cross-pollination

transfer of pollen from anther → stigma from another flower of same species

Micropyle

pore in integuments of an ovule; penetrates by pollen tube

Double fertilization

2 sperm cells unite within 2 cells in female gametophyte (embryo sac)

Endosperm

nutrient-rich tissue that provides nourishment to embryo in angiosperm seeds

Cotyledons

seed leaf in angiosperm embryo

Monocot

one cotyledon

Dicot

two cotyledons

Eudicot

”true dicots” (larger dicot clade)

Basal angiosperms

”basal” = bottom; flowering plants that have diverged from the lineage leading to most flowering plants;

Amorella spp.,water lilies, star anise

Magnoliids

8500 species

Magnolias, laurels, black pepper; Magnolia grandiflora (flowers measure up to a foot across)

Monocots

72000 species

Orchids, grasses, palms

Eudicots

2/3 of angiosperms - 230000 species;

Largest group = legumes;

Roses, ornamental flowers, species with edible fruits, flowering trees (oak, willow, walnut, maple, burch)

**Terrestrial adaptations in seed plants to generate diversity**

Seeds, reduced gametophyte (larger sporophytes), heterosporous, ovules, pollen → allow for coping with environmental conditions (drought, UV radiation, etc) and water not necessary for reproduction

Spores; seeds

________ require water for reproduction but ____ do not.

angiosperm

Life Cycle of ______:

Many different cells, but only one is the egg; Cross pollination; Double fertilization; Embryo Sac, microphyles, endosperms, and cotyledons

gymnosperm

Life Cycle of ____:

Ovule cones vs pollen cones; Pollination occurs when pollen grain reaches ovule; Sporophyte = pine tree; Heterosporous conifers (produce cones)

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Microsporangia → microsporocytes → microspores → pollen grains

Megasporangia → megasporocytes → megaspores → Archegonium (produces egg)

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3

Most pine species have **both** ovulate and pollen cones. From the time that both appear on the tree, it takes \~_ years for the male and female gameto. to be produced and come together. Scales from each ovulate cone separate → seeds are dispersed by wind → pine seedling

Reduced male and female gametophytes

develop within parental sporophytes, protected from environmental stress

pollen

protects male gametophytes (which produce sperm) and can be transported by wind or animals

ovule

 protect female gametophytes (which produce eggs)

seed

An ovule fertilized by pollen develops into a _____

Cell

fundamental unit of life

Tissue

group of cells that work together to perform a specialized function

Organ

group of tissues that carry out specific functions

Root System

anchor the plant, absorb water/minerals, store food, almost never photosynthetic

Shoot System

source of photosynthetic products; arial (top) portion of a plant body consisting of leaves, stems, and flowers; depends on water and minerals that roots absorb from soil

Primary Root

First plant root and organ to emerge from germinating seed; branches to form lateral roots

Taproots

main vertical root that develops from primary root

Root Hairs

thin, finger-like extensions of root epidermal cells are the trips of roots increase the surface area for absorbing water and minerals; often form mycorrhizae

Stem

support and elevate leaves, maximizing photosynthesis

Nodes

where leaves attach

Internodes

segments between nodes

Apical bud

bud at tip of plant stem

Axillary bud

found in the angle between a leaf and stem - can become a branch

Leaves

main photosynthetic organ of vascular plants

Blade

flattened portion of leaf

Petiole

stalk that joins the leaf to the stem at a node

Veins

vascular tissue; Monocots → parallel; Eudicots → branched

Tendrils

“curl” for support and attachment

Spines

help plants survive hot/dry environments and acts as a defense mechanism

Reproductive Leaves

can fall off a leaf and take root in soil

Dermal Tissue

outer covering protects organs; similar to skin; first line of defense against physical damage and pathogen

Cuticle

waxy epidermal coating to prevent water loss

Guard Cells

involved in gas exchange

Trichomes

hairlike outgrowth on shoot

Vascular Tissue

provides support and transports resources

Xylem

conducts water and other dissolved minerals upward from roots to shoots

Phloem

transports sugars and photosynthetic products (leaves → developing leaves or fruits)

Ground Tissue

store sugars, photosynthesis, support

Pith

internal to vascular tissue

Cortex

external to vascular tissue

Parenchyma Cells

thin/flexible cell walls; lack secondary walls; commonly makes up fleshy tissue of fruits

Collenchyma Cells

thicker primary walls than parenchyma; uneven thickness of cell walls; help support young parts of plant shoot

Sclerenchyma Cells

have secondary cell walls (thick and contain lignin - indigestible fiber found in wood); occur in regions of plants that have stopping growing in length

Indeterminate Growth

occurs throughout a plant’s life

Determinate Growth

stops after organism reaches a certain size (occurs in most animals and some plant organs)

Meristems

allows continuous growth in plants

Apical Meristem

located at root and shoot tips; enable primary growth (length)

Lateral Meristems

thickens roots and shoots of woody plants; allow for secondary growth (thickness)

Vascular Cambium

adds secondary xylem (wood) and secondary phloem; As cells divide, they increase circumference - each ring is larger than previous

Cork Cambium

replaces epidermis within thicker, tougher covering of waxy cells (protection, prevent water loss, and prevent microbial invasion

Primary Meristems

derivatives of apical meristems

Protoderm

dermal tissue

Ground meristem

ground tissue