Biology II Exam III

opisthokonta

• contains certain closely related protists

• Kingdom Fungi

• Kingdom Animalia

• have flagellated cells

fungi arose from…

protists related to amoebas that engulf

fungi are closely related to…

animals

fungi characteristics

• heterotrophic

• absorptive nutrition

• stores surplus food

unique characteristics of fungi

• mycelia composed of hyphae → hidden

• fruiting bodies (reproductive structures) → visible

• reproduction process

reproduction of fungi

reproduces both sexually and asexually

• plasmogmy

• karyogamy

• meiosis

how are haploid spores created

• 2 unmated haploid individuls (mycelium)

  • combines hypha to mate and create a mushroom

    • creates haploid spores

mushroom

dikaryotic with 2 nuclei in one cell

plasmogamy

sexual phase where protoplasm of 2 parent cells fuse

karyogamy

fusion of haploid nuclei into one diploid nucleus

meiosis

produces haploid gametes

distinctive growth processes of mycelia

• grows quickly

• at edges

• narrow dimensions and extensive branching provides high surface area for absorption

  • example: fairy ring

mycelium shape

irregular

conidia

asexual spores at the tips of hyphae

fruiting bodies of fungi (mushroom)

adapts for the spores

• dependent on dispersal via wind, rain, or animals

some fruiting bodies produce substances to deter consumption

• toxins or psychoactive substances

ergotism

convulsions, mania

• ergot fungi grows on rye and similar plants

fungi role in ecology

decomposers

• since they can break down cellulose

mycoses

diseases caused by fungi

modes of infection of fungi

• inhalation

• trauma

• ingestion

• rarely from person to person (mycoses)

“ringworm” or dermatophytosis

• 20% of Americans get infected

• different types of ringworm are grouped by Latin names

mycorrhizae

association between the HYPHAE of certain fungi and the ROOTS of most seed plants

• 80% of terrestrial plants have mycorrhizae

endophytes

• lives within the leaf and stem

• obtains organic food molecules from plants

• contributes toxins OR antibiotics that deter foraging organisms

plants with endophytes often grow ______ than plants without

BETTER

lichens

• mutualism → fungi and photosynthetic green algae/cyanobacteria

kingdom chytridiomycota

• only fungi to produce flagellate cells → for spore or gamete dispersal

• some species cause chytridiomycosis

kingdom zygomycota

most are saprobes in soil
(decomposes dead or decaying organic material)

kingdom glomeromycota

arbuscular mycorrhizal (AM) fungi

• penetrates the cortical cells of vascular plants roots

• characterized by ARBUSCULES

kingdom Ascomycota

produced inside

• produces sexual spores called ascospores

kingdom basidiomycota

produces sexual spores called basidiospores, produced outside

• mushrooms, puffballs, stinkhorns, shelf fungi, rusts, and smuts as fruiting bodies

animal diversity characteristics

• multicellularity

• heterotrophs

• no cell walls

• nervous tissue

• capacity to move

animal diversity traditional classifications

• monophyletic

• ~35 recognized animal phyla

• likely ancestor is a colonial flagellated protists similar to choanoflagellates

4 traditional main morphological and developmental features

1. presence or absence of different tissue types

2. type of body symmetry

3. presence or absence of a true body cavity

4. patterns of embryonic development

all animals are….

metazoa

metazoa

2 subgroups

• without specialized tissue → PARAZOA (sponges)

• with specialized tissue → EUMETAZOA

eumetazoa are either …

radially symmetrical (radiata) or bilaterally symmetrical (bilateria)

number of germ cell layers

radiata → diploblastic

• 2 germ layers

• endoderm and ectoderm

Bilateria → triploblastic

• 3 germ layers

• endoderm, mesoderm, and ectoderm

blastula

early embryo with differentiated germ (cell) layers

true coelom

body cavity is completely lined with mesoderm

pseudocoelom

coelom is not completely lined by tissue derived from mesoderm

acoelomates

lack a body cavity entirely

in a developing zygote…

• cell cleavage may occur by two mechanisms

  • spiral or radial

spiral cleavage (protostomes)

• cleavage determinate

• blastopore become mouth

• animals called protostomes

radial cleavage (deuterostomes)

• cleavage is indeterminate

• blastopore becomes anus

• animals called deuterostomes

exoskeleton

external skeleton

notochord

embryonic spine

segmentation

specialized body regions

comparing similarities in DNA, in particular…..

from ribosomal RNA of animals

agreements between traditional and molecular phylogeny

1. metazoa is monophyletic

2. split between parazoa and eumetazoa

3. early split between radiata and bilateria

4. echinoderms and chordates belong to Deuterostomia

differences between traditional and molecular phylogeny

1. less clear relationships among bilateria

2. presence or absence of a body cavity not useful

current molecular views on bilateria

before

• deuterostomia and protostomia

after

• protostomes split into lophotrochozoa and ecdysozoa

phylum porifera (sponges) important characteristics

1. lack specialized tissue

2. no apparent symmetry

3. adults are sessile → larvae are free-swimming

sponges → feeding

water is pulled through pores into spongocoel

→ trap and eat small particles/plankton

sponges → reproduction

asexual

• small fragment or bud detach and form new sponge

sexual

• most are hermaphrodites that produce egg and sperm

sponge structure

spongy part

• spicules (calcium or silica)

• and/or spongin (collagen)

• → skeletal fibers of sea sponge

Phyla Cnidaria and Ctenophora important characteristics

1. exclusively marine

2. radial symmetry

3. 2 embryonic germ layers

Phyla Cnidaria and Ctenophora structure

• gastrovascular cavity

• nerve net

cnidocyte cells

single use explosive cells with hairlike triggers

• used for prey capture and defense

comb jellies important characteristics

• two long tentacles without stinging cells

• first complete gut with mouth to anus

lophophore

crown of ciliated tentacles (feeding organ possessed by four major groups of animals)

trochophore

a type of free swimming planktonic marine larva with several bands of cilia

lophotrochozoa important characteristics

1. have a lophophore or trochophore stage

2. bilateral symmetry

lophotrochozoa → phylum platyhelminthes | important characteristics

1. head

2. lack of specialized respiratory or circulatory system

3. first with 3 embryonic germ layers

mesoderm key innovation led to….

more sophisticated organs

lophotrochozoa → phylum platyhelminthes | 4 classes

1. turbellaria → free-living, planaria

2. monogenea → fish flukes

3. cestoda → tapeworms

4. trematoda → flukes

2-4 are parasites

cestode example → tapeworm

‘worms’ that are intestinal parasites to humans

scolex ‘head’

anterior organ for attachment to the intestine (asexual)

strobila ‘body’

composed of successive segments called proglottids (sexual) → growth called strobilation

eat undercooked meat with cysts →

taeniasis in humans (worm in intestines)

eat eggs from human feces →

cysticercosis in humans (cysts in body tissue)

phylum rotifera

digestive tract with mouth and anus

parthenogenesis

unfertilized diploid eggs → females

unfertilized haploid eggs → males