Botany Exam 3

Which of these is NOT a part of a gametic life cycle?

Alternation of generations

Coevolution can be defined as;

An alliance between species that influence the evolution of each other.

Plant-animal coevolution strategies are important to humans too

An apple orchard needs pollinating agents for better yield A squash garden needs pollinators to carry pollen from male to female flowers

Where are female gametophyte eggs produced?

Archegonia (n)

Where do you find integument? What does integument become at later stages?

Around the megasporangium in the ovule of all seed plants, later becomes the seed coat

Your friend brags to you about his fearless adventures in the Alaskan wilderness where he was once lost for several weeks and survived by eating fruits of giant conifers that were the only available food in that area. You laugh and tell him, "that can't be true". Why?

Because conifers do not produce fruits

Why do Bryophytes, Lycophytes and Peridophytes prefer to grow in moist habitats closer to water?

Because they have swimming sperm that need a film of water

Mutualism

Benefit Both

Commensalism

Benefit one, harm to other

Parasitism

Benefit one, harmful to other

Which sequence represents the correct order in which land plants became more advanced in structure and function during their evolution?

Bryophytes, Lycophytes, Pteridophytes, Gymnosperms, Angiosperms

Coevolution for protection

Bullhorn ants live in hollow thorns of ant acacia plant The plant produces nectar and food bodies to feed ants The ants protect the plant from herbivores

Seeds Plants Appear in the

Carboniferous Era

Staminate

Carry only male organs

Ephedrine: for asthma relief

Comes from the Ephedra plant (Gnetophyta) (Originally used as a nutritional supplement, now classified as a medicine)

Monotropa

Completely heterotrophic angiosperm that draws nutrients from soil fungi. Plants can be parasitic in fungi

Anthers

Contain Microsporangia divides by meiosis...goes to microgametophytes (pollen)...sperm

Male Gametophytes in Seed Plants

Contained within the microspore Male Gametophyte produces sperm inside the pollen grain

Which two phyla are considered as the most primitive among Gymnosperms, and why?

Cycadophyta and Ginkgophyta because they have swimming sperm

What is the popular landscape plant?

Cycadophyta. Produce large cones that produce microspores and mespores. Gametophytes are extremely reduced to few cells

Cycaophytes

Dependent on the Sporophyte

Which came first; Monocots or Dicots?

Dicots, then monocots

Mycorrhizae inside plant roots come in two forms

Ectomycorrhizae Endomycorrhizae

Cycads have mutualistic symbioses with Cyanobacteria in roots

Example: Corraloid roots harboring Cyanobacteria. May form a ring with cyanobacteria.

When flowers are self pollinated, they get their own pollen onto the stigma of a flower, therefore, it can be considered as a form of asexual reproduction.

False, because pollen and eggs are not identical due to meiosis in sporangia

Your friend says; A symbiotic relationship between two organisms is beneficial to both organisms involved. You say:

False, these relationships may benefit both or only one partner.

Pistillate

Female organs only

Mycelium

Filaments aka HYPHAE make the body of the fungus (mycelium)

Nitrogen Fixation in Legume Root Nodules

Flavonoids secreted by plant roots to attract rhizobium. Rhizobium Enter the Root and colonize Plant root develops the nodule and accessory elements to house them. Bacteria Modify to life inside plant and fix nitrogen.

Highly Evolved Leaves

Floral parts

Monocotyledonous (monocots)

Flowers in threes, vascular bundles scattered, one pore/furrow in pollen. grasses, grains, orchids, palms etc.

Tight coevolution could be a survival strain

If one partner becomes extinct => other partner may be forced to become extinct or evolve fast. For 40 million years yucca plant and yucca moth coevolved. Neither can survive without the other.

Where is the sporophyte the smallest?

In Phylum Hepatophyta (Bryophytes)

Plant Diseases Caused By Bacteria

Internal Defenses to recognize pathogen Ex: Hypersensitive response and SAR

In Gymnosperms as well as in Angiosperms, the female gametophyte is very small. How does it feed the developing embryo?

It draws nutrients from the parent sporophyte tissues.

Ginkgo biloba is the only species in the phylum Ginkgophyta. Why have scientists given this one species its own phylum?

It is the only remaining species of a previously larger group

What does the microsporangia produce within the anters?

Male Gametophyte aka microgametophyte aka pollen grain

What does the ovule contain?

Megasporangium with one megaspore mother cell.

The development of female gametophyte

Megaspore mother cell is 2n Megasporangium is 2n Integument 2n Ovule is sporophyte tissue is 2n

The development of female gametophyte

Megaspores (n) Female Gametophyte is (n) Archegonia (n) Egg Cells (n)

How does meiosis increase genetic variation in plants?

Meiosis is a reduction division -shuffles alleles in homologous chromosomes -separates homologous chromosomes -endless new allele combinations -results in unique new cells -produces cells with half the number of chromosomes

The seed is what?

Mini embryo of the future sporophyte (2n). Dispersal stage of the life cycle. Dry seeds can withstand adverse conditions and can remain dormant for many years.

Phylum: Coniferophyta

Most diverse group among Gymnosperms Commonly known as "conifers" Highly resinous stems, Needle-like leaves, Cones bearing eggs/seeds or pollen examples: pines, junipers, firs, spruces

Fiddleheads

Newly forming fronds that are tightly coiled

Coevolution for dispersal of seeds by animals

Omphalocarpum fruit seedlings can grow in elephant shit

Where does pollen land?

On the stigman

Phylum: Ginkgophyta

Only one living species on earth Ginkgo biloba. May also be called maidenhair tree. Living fossil.

Where does development occur in Cycads?

Ovules with fertilized eggs develop into exposed seeds on megasporophylls

Among all land plants, which phylum carries the smallest and least advanced sporophyte generation?

Phylum Hepatophyta

True stems with vascular tissues can be seen among (choose all that apply)

Phylum Lycopodiophyta Phylum Pteridophyta Phylum Equisetophyta

Cycad corraloid roots in symbiosis with cyanobacteria

Plants will provide nutrients/protection to the cyanobacterium (ANABAEN, NOSTOC) which will provide fixe nitrogen and toxins to the plant Example: Azolla is symbiotic with Anabaena

Evolution

Process by which populations change with time due to selection pressure from the environment they live in

Mushrooms Eaten Are

Reproductive Organs of the fungus

Cross pollinating flowers

Show mechanisms that prevent self pollination and promote cross pollination

Whorl 4

(innermost) female reproductive organ - consists of one or several carpels (separate or fused into one structure

Bird-pollinated flowers

- Bright colored, mostly red - No landing platform Nectar present as reward

Butterfly-pollinated flowers

- Flowers are bright colored - Provide landing platform - Sweet fragrance - Nectar - Slender tubular corolla - - Butterflies evolved with long mouthparts (e.g. proboscis)

Importance of Gymnosperms

- Food and flavor for human use: pine nuts, juniper berries - Food for birds and other small animals

Self pollinating flowers

- Must be perfect flowers - Anthers and stigma mature at the same time - Anthers can touch stigma or placed above stigma - Usually less colorful

Bee pollinated flowers

- Not red, sweet minty fragrance - Provide landing platform for the bee to land on the flower - Provide nectar guides on petals

Fly-pollinated flowers

- Smells like rotten meat - red/brown colors - Nectar present Landing platform

Mechanisms to promote cross pollination

- Stamens below stigma - Imperfect flowers - - Self-incompatibility if perfect flowers - Male and female plants Ex: Squash

Bat-pollinated flowers

- Strong fermenting smell - night blooming large pale colored flowers - Nectar present

Moth-pollinated flowers

- White or light colored - Mostly open at night - Nectar & heavy fragrance - Landing platform present or absent (some moths hover, some land)

Abiotic agents: Wind or water pollinated flowers

- colorless, mostly imperfect flowers - No nectar, no fragrance - Large stigma - No / tiny petals

Mutualistic Coevolution Between Plants and Animals

- pollination - seed dispersal - protection

ABC Floral Development

-A only = sepals -A and B = petals -B and C = stamens -C only = carpels

Gametophytes and Sporophytes in the Sporic Life Cycle

-Bryophytes have smaller sporophyte that is dependent on gametophyte -Lycophytes and Pteridophytes have sporophyte independent of gametophyte -Seed plants have sporophyte completely dependent on gametophyte

Seeded Plant Evolution of Characteristics

-Chlorophyta (aquatic green algae, Dom. gametophyte, ZYGOTIC life cycle) -Bryopyhtes (non-vascular, Dom. gametophyte, SPORIC life cycle, homospory) -Fern Allies (vascular, Dom. SPOROPHYTE, STEMS AND ROOTS, MICROPHYLLS, HETEROSPORY) -True Ferns (TRUE LEAVES)

Order of seedless plant evolution

-Chlorophyta (green algae) -Bryophytes -Lycophytes (fern allies) -Pteridophytes (true ferns)

Characteristics of seed plants

-Dominant sporophyte - Gametophyte completely dependent on sporophyte - Well developed vascular system, roots, stems, leaves

The gametophytes of seed plants

-Extremely small, nonphotosynthetic and unisexual (separate male and female gametophytes)

What causes vegetative meristem to become floral meristems?

-Internal signals (hormomes/metabolites_ -Environmental cues (temp, day length, stress factors)

Meiosis events

-Meiosis I (PMAT I) Homologs seperate -Cytokinesis I -Meiosis II (PMAT II) Sister Chromatids seperate -Cytokinesis II

Lycophytes

-Phylum Lycopodiophyta -vascular system (stems, roots, microphylls) -FIRST SIGN OF HETEROSPORY

True Ferns

-Phylum Psilotophyta, Equisetophyta, and Pteridophyta -DOMINANT SPOROPHYTE -true leaves first seen

Bryopyhtes

-Phylums Hepatophyta and Bryophyta -next step from algae, need close water -moist environments -flagellated sperm need water -no vascular tissue -no true organs (stems, leaves, roots)

Cycads seeds and leaves..

-Seeds and leaves of cycads can be poisonous

What is a Fungi?

-Some Unicellular -Most are multicellular and filamentous

Fern Life Cycle

-Sporophyte produces sporangia (SORI) on underside of fronds -MEIOSIS IN SPORANGIA -Spores (haploid) -Gametophyte (haploid)

3 Stages of Development in Flowering Plants

-Vegetative Stage -Reproductive Stage -Senescence

Sporic Life Cycle

-all plants -alteration of generations -multicellular haploid and diploid generations alternate -lower plants (Bryophytes) have haploid dominant -lycophytes onward have diploid dominant

Gametic Life Cycle

-animals, some algae -produce gametes directly through meiosis -gamete only haploid stage -DOMINANT DIPLOID

Angiosperm characteristics

-arid, wet, aquatic, saline, hot, cold. Exhibit all growth forms (trees, shrubs, herbs, vines) - Mostly autotrophic, but few heterotrophic species

True Leaves

-branched veins -True Ferns onwards

How is pollen dispersed?

-by anther dehisence -pollen grains land on stigma -pollen tube grows inside the style to reach ovary -after pollenation, g cell nucleus divides by MITOSIS to produce 2 sperm nuclei -tube nucleus controls the pollen tube growth into an ovule

Importance of Bryophytes

-common starter species for poor soils -common foundation for food chains -wide distribution

Where does meiosis occur in the plant life cycle?

-diploid sporophyte produces haploid spores by MEIOSIS -haploid spores develop into gametophytes -gametophytes produce gametes by MITOSIS -haploid gametes (female+male) come together to form genetically unique sporophyte zygote

Bryophyte Life Cycle

-dominant gametophyte (haploid) -diploid sporophyte grows and depends on dominant gametophyte

Dicot seed

-each seed carries an embryo (future sporophyte) -endosperm recedes as two cotelydons that grow bigger as they extract nutrients from endosperm -mature seeds dispersed from parent plant -germinate into new sporophyte

Monocot seeds

-endosperm remains large -cotelydon is a small part of embryo

Phylum Bryophyta (mosses)

-erect body form -no vascular system (no stems/leaves/roots) -rhizoids to anchor -archegonia and antheridia form at gametophyte tips -sperm spreads by wind and water and swims to fertilize egg -diploid zygote forms -produces diploid sporophyte at female plant tip

Megagametophyte

-female -few cells inside ovule -contained and nourished within sporophyte

Pistil

-female part -ovary and bottom -stigma at top -style connects ovary to stigma

Sexual Reproduction in Plants

-female+male gametes = zygote -meiosis occurs in one stage in the life cycle -increases genetic variation -accelerates adaptations -promotes evolution -produces unique haploids/progeny

Archegoniophores

-female, in bryophytes -umbrella shaped with arms -produce eggs

Vegetative Stage

-first stage of flowering plant development -increase size -produce more roots, leaves, and branches

Dicotyledonous (dicots

-flowers in 4/5s -vascular bundles in rings -three pores or furrows in pollen peas, roses, oaks, cacti etc.

How Angiosperms and Gymnosperms differ

-flowers with male and female spores -ovules are enclosed in sporophytic tissues, which are fruits after fertilization

Gemmae cups in Bryophytes

-for asexual reproduction -gametes produced by MITOSIS

Zygotic Life Cycle

-in protists (algae) -DOMINANT HAPLOID -produce spores through MEIOSIS -zygote is the only diploid stage

Megaspores

-large -female -in megasporangia

Microphylls

-leaves with a single vein -in lycophytes

Microgametophyte

-male -2 cells inside pollen -dispersed from sporophyte

Stamen

-male part -anther at top -filament raises it to stigma

antheridiophore

-male, in bryophytes -disc shaped -produce flagellated sperm

Fruits

-mature ovaries -carry seeds -highly evolved to protect young seeds -disperse mature seeds

How is pollen formed?

-meiosis inside of MICROsporangia in anthers prodice microspores that become pollen

What happens in the ovule during sexual reproduction?

-meiosis inside ovule produces megaspore that develops into a female (mega) gametophyte -pollen tube grows into ovule -one sperm nucleus fertilizes the egg cell nucleus

Shrinking Gametophytes in Seed Evolution

-microscopic gametophytes in seed plants -exist within spores -depend on sporophytes

Importance of true ferns

-most of oil reserves from fossilized ferns -ornamental house plants

Phylum Psilophyta (whisk ferns)

-most primitive ferns -dichotomous branched stem (splits into two) -no leaves or roots -homosporous

Where do the two sperm nuclei go when in the ovary?

-one fertilizes the egg cell nucleus to form 2N zygote -the other joins the two polar nuclei to form 3N endosperm

Pollination and double fertilization

-pollen grain lands on stigma -pollen tube germinates into ovary -pollen tube carries two sperm nuclei -one sperm fertilizes egg to form 2N zygote -other sperm joins with two polar nuclei to form 3N endosperm

Endosperm

-provides food for embryo

Reproductive Stage

-second stage of flowering plant development -produce flowers, fruits, and seeds for sexual reproduction

Phylum Equisetophyta (horsetails)

-segmented stems arise form rhizome -tiny microphyll leaves -TRUE ROOTS -homosporous -sporangia in cone called STROBILUS

Phylum Hepatophyta (liverworts)

-simple body form -rhizoids to anchor -gametophyte forms archegoniophores and antheridiophores to produce gametes -sperm fertilizes egg to form diploid zygote in archegonia -sporophyte grows from zygote, still in archegoniophore -sporophyte, thru meiosis, produces haploid spores -haploid spores germinate to form haploid gametes

Microspores

-small -male -in microsporangia

Early plants

-small -no roots, stems, flowers, or seeds -evolved from green algae (chlorophyta)

Heterospory is seen in

-some lycophytes -some pteridophytes -all gymnosperms -all angiosperms

Senescence

-third stage of flowering plant development -individual organs or whole plant wither and die :(

Pollen grains contain

-tube cell -tube cell nucleus -generative cell

After fertilization in Angiosperms

-zygote develops into embryo (future sporophyte) -the 3N endosperm provides nutrition to the embryo -ovule develops into seed that protects embryo -integument becomes seed coat -ovary develops into fruit

After fertilization in plants

-zygote is the fertilized egg -embryo inside seed -becomes future sporophyte

Result of Meiosis in Plants?

4 genetically different haploid spores

Mycorrizhal

90% of plants benefit from it. Increases surface area for absorption. Plant will provide carbs to the fungus.

Phylum: Gnetophyta

About 70 living species Very unusual looking, often in dry habitats Some genera show features similar to Angiosperms May not be the true lineage of Angiosperm evolution

Coevolution

The process by which two or more groups of organisms influence each others evolution. May be beneficial or rivalry

What does the whole ovule in gymnosperms develop into?

The whole ass seded. The seed coat is 2n. It is also a modified integument from the parent plant. Embryo is 2n and is the new sporophyte.

Gnetophytes have some advanced characteristics in common with angiosperms. Why are they classified as gymnosperms?

Their seeds are naked

Which of these are true about heterospory? Choose all that apply. Penalty for wrong choices. (Hint: 3 correct answers)

There are megaspores and microspores Heterospory first appeared in Lycophytes Heterospory paved the way for plants to evolve seeds

Why are gymnosperm seeds said to be naked?

They are not enclosed within a fruit.

What characteristics among these are typical to both gymnosperms and angiosperms? Choose all that apply. Penalty for wrong answers. (Hint: 4 correct answers)

They are vascular plants with true stems and leaves Their female gametophyte is contained within the sporophyte Their pollen represent the male gametophyte Their male gametophyte travels to the female gametophyte

Which statement is true about a difference between fern allies and true ferns?

True leaves are present in true ferns but not in fern allies

During the event known as double fertilization, which of these is/are fertilized by a sperm nucleus to generate the 3N endosperm?

Two polar nuclei

Dicots and monocots differ from each other in several ways. Select all answer choices that describe differences between them. Penalty for wrong answers. (Hint: 3 correct answers)

Venation pattern in the leaves of dicots and monocots differ Dicots produce two cotyledons, monocots produce only one The arrangement of vascular bundles in dicot and monocot stems differ

Seed Plant Female Gametophytes

Within the ovule of sporophyte. They produce egg cells.

The fruit is;

a mature ovary

Whorl 3

Stamens - male reproductive structures each consists of a filament and anther lobes

What happened to the gametophyte stage during the course of evolution of land plants?

became smaller and more dependent on sporophyte

Why have some plants coevolved with animals for pollination, rather than depending on physical forces like wind and water for pollination?

because coevolved animals are more reliable in carrying pollen between flowers

Which of these is NOT a part of a flower?

bract

Phylum Cycadophyta

cycads (i.e. sago palm) Primitive Group. Flagellate sperm similar to Bryophytes, Lycophytes, and Pteridophytes.

Whorl 2

usually large, colorful, showy Adapted to attract pollinators to the flower

Megaspore cell will..

divide by meiosis into four haploid cells where one cell will become the megaspore and the other three cells will degenerate

What is the unique feature of the Angiosperm Life Cycle?

double fertilization

How does the megagametophyte develop from this megaspore?

each megaspore produces a megagametophyte (female gametophyte), which ultimately produces female gametes (eggs). Fusion of an egg and a sperm creates a zygote and restores the 2n ploidy level. The zygote divides mitotically to form the embryo, which then develops into the sporophyte.

What is carried inside the seed of a gymnosperm?

embryo of the future sporophyte

Fronds

fern leaves

Angiosperms

flowering plants Phylum Anthophyta Most advanced evolutionary features, therefore dominant

Gnetophyta advanced feature

has tracheids and vessel elements

Ectomycorrhizae

have hyphae that do not enter into root cells

Cycadophyta, Ginkgophyta and Coniferophyta

have only tracheids in the xylem for water transport (primitive feature

Rhizomes

horizontal underground stems, give rise to roots

The ABC model explains;

how different whorls of flower parts are determined

The double fertilization is seen;

in all angiosperms and some gymnosperms

What words should go in the blanks? In the life cycle of a land plant, diploid sporophyte produces spores using cell division by ____, and haploid gametophyte produces gametes using cell division by ____ .

meiosis, mitosis

In seed plants, which of the following would be dispersed away from the parent plant?

microgametophytes and seeds

The zygote of an angiosperm undergoes _______________ to produce the embryo, that develops into the __________________ .

mitosis, future sporophyte

Leaves come from

modified stems and branches

Monocot endosperm

more than in dicots

Seeds Plants are the

most advanced vascular plants

How do you tell if a symbiotic relationship is a mutualism or commensalism?

mutualism benefits both, commensalism benefits one without harming the other.

A farmer owns a successful organic apple orchard. For many years he has had excellent yield from his trees. This year his orchard yielded very poorly even though he had not changed his farming strategies, and weather was very consistent. Which of the following reasons might best explain the drop in fruit production?

only answers A and C could be possible explanations

double fertilization

only found in angiosperms and produce a structure called endosperm inside the seed

Perianth

petals and sepals

Refer to the ABC model of floral organ development. Gene A is expressed in whorls 1 & 2, gene B is expressed in whorls 2 and 3, gene C is expressed in whorls 3 & 4 (whorl 4 is the innermost). A scientist used genetic engineering techniques to express gene B in all whorls. What would the pattern of floral organs in the resulting transgenic plant be?

petals, petals, stamens, stamens

Pathogenic fungi

plant diseases are caused by fungi Ex; mildews, rots, rusts, smuts, anthracnose Plants have also developed mechanisms to resist infections (coevolution for defense)

Your aunt who is highly allergic to bee stings, loves flowers but would like to keep bees away. What would be your best advice to her about the types of flowers she should have in her garden?

plant mostly bright red, long tubular flowers without landing platforms

Whorl 1

sepals - usually small, green (photosynthetic) protects the unopened flower in bud

Dicot endospem

smaller and gets fully eaten by two cotelydons

The microgametophyte of a Gymnosperm should produce;

sperm

A plant lives in a remote valley, with only a few other flowering plant species nearby. It reproduces only sexually by being pollinated only by one specific butterfly species, which pollinates most of the plant species in the valley. Also living in the valley is a bird that eats only the fruit of the plant and preys on the butterfly. Extinction of which of these three species would cause the extinction of the other two?

the butterfly

What is the sexual organ in Angiosperms?

the flower

According to the description of "true leaves", a feature seen in true leaves but not in microphylls is;

the presence of branched veins

What is a correct statement describing a relationship between ovules and seeds in "both gymnosperms and angiosperms"?

the unfertilized egg cell inside the ovule becomes the embryo inside the developing seed after fertilization

In the evolutionary history of land plants, which of these is a landmark evolutionary feature appeared in Lycophytes?

they evolved the dominant diploid sporophyte generation

What is always true about heterosporous plants?

they produce small male microspores and large female megaspores

What is the advantage to a tomato plant in having green unripe fruit and red ripe fruit?

this lowers the chance that immature seeds are dispersed by animals

Rhizoids

anchors, but does NOT absorb anything

All living gymnosperms

are woody plants. produce secondary growth by the activity of vascular cambium and cork cambium

Which of the following statements most accurately explain what recent molecular evidence shows about monocots and dicots?

dicots were the first to emerge, and monocots separated later from a dicot ancestor

receptacle

Four whorls rest on here

How does self-incompatibility happen

Genes activated on the stigma prevent pollen from the same flower from germinating on the stigma. Sometimes, genes activated in the pollen abort the pollen tube growth

Nutrition supplements

Ginkgo extract improves blood circulation to the brain and lungs

Plants Interaction with Fungi

Good: Mycorrhizal fungi. Decomposers that recycle nutrients from dead plant matter back to soil Bad: Pathogens that cause diseases

Plants interaction with Prokaryotes

Good: Nitrogen Fixation. Protection Bad: Bacterial Diseases

Fungal Mycelia

Help absorb phosphorus and nitrogen from soil

What was the gateway to seeded plant evolution?

Heterospory

Receptacle

The base of a flower

Carpels

The female reproductive organ of a flower, consisting of the stigma, style, and ovary.

Pollination syndromes

The morphology and behavior can help predict the mode of pollination. Ex: Abiotic and Biotic Agents

Heterospory is a feature that is invariably found in;

all seed plants

Homosporous

all spores are the same size

What is the function of the pollen tube in an Angiosperm?

delivering two sperm into the ovule

Here is something to think about. Read patiently! You treated a developing flower of a self-pollinating diploid angiosperm with a chemical that disrupts sister chromatid separation in the anaphase II of meiosis during both microspore and megaspore formation, producing spores that have double the number of chromosomes. If the plant pollinates itself, what would you expect as the ploidy of the integument, zygote and endosperm?

integument 2N, zygote 4N, endosperm 6N

Cyanobacteria in symbiosis with roots

produce a toxic amino acid

Endomycorrhizae

produce structures that enter root cells

Male Cone of Cycadophyta

produces microspores and pollen grains on microsporophylls

Female Cone of Cycadophyta

produces ovules on megasporophylls