Bio 2 Exam 3 Flashcards
What makes up the Opisthokonta?
- certain closely related protists
- Kingdom Fungi
- Kingdom Animalia
Where did fungi come from?
Arose from protists related to an amoeba that feeds by engulfing cells
What are the reasons that fungi are closely related to animals?
- both heterotrophic (cant produce own food)
- both use absorptive nutrition (secrete enzymes and absorb resulting small organic molecules)
- both store surplus food (as carbohydrate glycogen)
What are some unique characteristics of fungi?
- most have mycelia (body of fungi) composed of hyphae
- fruiting bodies are the reproductive structures
What makes up the fungi reproduction?
- two unmated haploid individuals (mycelium) combine hypha to mate and create a mushroom (dikaryotic with 2 nuclei in one cell) then create a haploid spore
What is plasmogamy (fungi)?
sexual phase where protoplasm of 2 parent cells fuse
What is karyogamy (fungi)?
fusion of haploid nuclei into one diploid nucleus
What is meiosis (fungi)?
produces haploid gametes
What is the distinctive growth process of mycelia?
- mycelia can grow quickly when food is plentiful
- grow at the edges
- narrow dimensions and extensive branching provides high surface area for absorption
What shape is natural mycelium?
irregular shape
What is the reproduction of fungi?
- many produce both sexually and asexually by spores
- many others reproduce only asexually
What is conidia?
asexual spores at the tips of hyphae
Structure of fruiting body (mushroom)?
varies in ways that reflect adaptations for spore dispersal by wind, rain, or animals
Which part of the fungi produces substances (toxins or psychoactive substances) to deter consumption?
Fruiting bodies
What are decomposer fungi?
- an essential component of ecosystems
- only certain bacteria and fungi can break down cellulose
- others are predators
Fungi pathogens
- 5000 species cause serious crop diseases
- rust spores can be spread by wind
What is mycorhizae (fungi)?
- association between the hyphae of certian fungi and the roots of most seed plants
- plants receive increased supply of water and mineral nutrients, and fungi get organic food molecules from the plants
What are endophytes (fungi)?
- live within the leaf and stem tissues of various types of plants
- obtain organic food molecules from plants—>in turn contribute toxins or antibiotics that deter foraging animals, insect pests, and microbial pathogens
- plants with endophytes often grow better than plants of the same species without endophytic fungi
What are lichens (fungi)?
- mutualism (partnership) of fungi and photosynthetic green algae and/or cyanobacteria
- fungus provides carbon dioxide, water, and minerals: and algae/cyanobacteria provides organic food molecules and oxygen
What is the kingdom Chytridiomycota?
- Simplest fungi (not monophyletic group)
- only fungi to produce flagellate cells
- for spore or gamete dispersal
- some species cause chytridiomycosis, an infectious disease of amphibians linked to dramatic population declines
What is Kingdom Zygomycota?
- most are saprobes in soil (decomposes dead or decaying organic material)
What is kingdom Glomeromycota?
- arbuscular mycorrhizal (AM) fungi
- penetrates the cortical cells of vascular plants roots
- AM fungi characterized by the formation of unique structures such as arbuscules
- the most prevalent plant symbiosis known, found in 80% of vascular plant families
What is kingdom ascomycota?
- produce sexual spores called ascospores
What is kingdom Basidiomycota?
- named for basidia that produce sexual spores called basidiospores
- produce mushrooms, puffballs, stinkhorns, shelf fungi, rusts and smuts as fruiting bodies
What are the 5 animal diversity characteristics?
- multi cellularity
- heterotrophs
- no cell walls (unlike plants)
- nervous tissue
- capacity to move
What is the most likely ancestor of animals?
- colonial (grouping) flagellated protist similar to choanoflagellates
- similarities between colonial cells and the cells sea sponges use for feeding
- multiple choanoflagellate group transitioning from swimming mode to feeding mode
What are body plans?
- before molecular methods, biological diversity was classified into four 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
What are tissues (body plans)?
- all animals are metazoa (divided into 2 subgroups)
—-parazoa: without specialized tissue (sponges)
—-eumetazoa: with specialized tissue
What are the two types of symmetry (body plans)?
- radially symmetrical (radiata)
- bilaterally symmetrical (bilateria)
What are ridiata body plan?
- diploblastic: 2 germ layers that form during the embryonic development
- have endoderm (inner layer)
- have ectoderm (outer layer)
What are bilateria body plan?
- are triploblastic: 3 germ layers that form during the embryonic development
- have endoderm (inner layer)
- have ectoderm (outer layer)
- have mesoderm (muscles and other organs)
What are the 3 body cavity types (body plans)?
- true coelom
- pseudocoelom
- acoelomates
What is a true coelom?
body cavity is completely lined with mesoderm (coelomates like earthworm, humans)
What is a pseudocoelom?
coelom is not completely lined by tissue derived from mesoderm (pseudocoelomates like nematodes)
What is a acoelomates?
lack a body cavity entirely (flatworms)
What are the 2 ways cell cleavage can occur (body plans)?
- spiral cleavage
- radial cleavage
What is spiral cleavage (protostomes)?
- cleavage determinate (determined very early)
- blastopore (opening of gut) becomes the mouth
- animals called protostomes (mollusks, arthropods, flatworms, nematodes)
What is radial cleavage (deuterostomes)?
- cleavage is indeterminate (any cell can still develop into an embryo, ex. stem cells)
- blastopore becomes anus
- animals called deuterostomes (sea stars, mammals)
What are the 3 traditional classifications of body plans?
- possession of exoskeleton (external skeleton)
- development of notochord (embryonic spine)
- presence or absence of segmentation (specialized body regions)
What does molecular views of animal diversity mean?
comparing similarities in the DNA in particular from ribosomal RNA of animals
What are the 4 agreements between traditional and molecular phylogeny?
- metazoa is monophyletic
- split between parazoa and eumetazoa
- early split between radiata and bilateria
- echinoderms (starfish) and chordates (mammal) belong to clade deuterostomia
What are the 2 differences between traditional and molecular phylogeny?
- less cleat relationships among bilateria
- presence or absence of a body cavity not useful
- ex. flatworms now include among the lophotrochozoa (traditional view was they had no coelom, but molecular evidence now indicates that they lost coelom)
What is the molecular views of animal diversity (bilateria)?
- traditionally bilateria split into deuterostomia and protostomia based on embryonic development
- molecular view now has protostomes split into lophotrochozoa and ecdysozoa
What are Lophotrochozoans?
- have lophophore (feeding tentacles) or/and trochophore larva/stage
- bilateral symmetry
What are Ecdysozoa?
molt nonliving cuticle or exoskeleton (process known as ecdysis)
What are Phylum Porifera (sponges)?
Important characteristics:
1. lack tissues
2. no apparent symmetry
3. adults are sessile –> larvae are free-swimming
How do sponges (parazoa) feed?
- water pulled through pores into spongocoel
- trap and eat small particles and plankton
How do sponges (parazoa) reproduce?
- asexual: small fragment or bud may detach and form a new sponge
- sexual: most are hermaphrodites that produce eggs and sperm
What is the spongy part of the sponge made of?
- spicules (calcium or silica) and/or spongin (collagen)—>skeletal fibers of sea sponge
What are Phyla Cnidaria and Ctenophora (radiata)?
Important characteristics?
1. exclusively marine
2. radial symmetry
3. 2 embryonic germ layers
What are 2 features seen in Phyla Cnidaria and Ctenophora?
- gastrovascular cavity (extracellular digestion for bigger food particles vs. intracellular digestion in sponges)
- nerve net (no central control)
What species make up Cnidaria)
- hydra
- jellyfish
- sea anemones
- coral
What is polyp and medusa forms (Cnidaria)?
- alternation of generation between 2 different (diploid) body forms
- sessile polyp with tubular body (asexual)
- free-swimming medusa with umbrella shape (sexual)
What are cnidocyte cells?
- seen in Cnidarians
- single use explosive cells with hairlike triggers
- can be sticky, toxic, harpoon-like, and/or entangle
- used for prey capture and defense
What are Phylum Ctenophora (comb jellies) (radiata)?
- 8 rows of cilia on surface with beat for propulsion
- two long tentacles without stinging cells
- first complete gut with mouth to anus
- bioluminescent-like
What is a lophophore?
crown of ciliated tentacles (feeding organ possessed by four major groups of animals)
What is a trochophore?
a type of free-swimming planktonic marine larva with several bands of cilia
What is Phylum Platyhelminthes (lophotrochozoa)?
Important characteristics:
1. head
2. lack specialized respiratory or circulatory system
3. first with 3 embryonic germ layers
- mesoderm key innovation led to more sophisticated organs
What are the 4 classes of Phylum Platyhelminthes?
- turbellaria: free living, planaria
- monogenea: fish flukes (parasite)
- cestoda: tapeworms (parasite)
- trematoda: flukes (parasite)
Example of platyhelminth?
trematode life-cycle (ribeiroia)
- ex. of Leucochloridium trematodes: larvae grow into long tubes in snail host to form swollen “broodsacs”. Broodsacs invade snails tentacles. Causes a change into a swollen, pulsating, colorful display that mimics the appearence of a caterpillar or group. Final host are birds
What is Phylum Rotifera (Lophotrochozoa)?
Important characteristics:
- digestive tract with mouth and anus
- parthenogenesis: unfertilized diploid eggs = females
unfertilized haploid eggs = males
What are the 3 major groups of Phylum Lophophorata?
- phoronida
- bryozoa
- brachiopoda
Important characteristics of Phylum Lophophorata (lophotrochozoa)?
- have a lophophore: ciliary feeding device that also functions in respiration
- true coelom (body cavity)
What is phronida (Phylum Lophophorara)?
- about 15 species
- elongated, tube-dwelling marine worms
- secrete tube often buried in group so only lophophore sticks out
What is Phylum Bryozoa?
- 4,000 species
- animal secretes and lives inside zoecium
What is Phylum Brachiopoda?
- 3,000 species
- marine with 2 shells
- dorsal and ventral valves
What is Phylum Mollusca (lophotrochozoa)?
Important characteristics:
1. soft body with in many species protective external shell
2. body has 3 parts
3. open circulatory system
- have radula (tiny teeth that scrape surfaces for food)
What is Phylum Annelida (lophotrochozoa)?
Important characteristics:
- rings are distinct segments separated by a septum
Advantages:
1. repetition of components provides backup
2. coelom acts as hydrostatic skeleton
3. permits specialization
- double transport system and coelomic fluid carries nutrients, wastes, and respiratory gases
What are the two groups of Phylum Annelida?
Polychaeta
- 10,000 species
- long setae
Clittelata
- subclass oligpchaeta terrestrial and freshwater worms (earthworms)
- subclass hirudinea: leeches
What is a clitellum?
thickened section on earthworms and leeches (secretes cocoon sacks)
What are Ecdysozoa (bilateria)?
- ecdysis = molting
- all acdysozoans possess a cuticle for support and protection
- branching air-filled tubes = tracheae
What is Phylum Nematoda (Ecdysozoa)?
Important characteristics:
1. tough collagen cuticle covers body
2. longitudinal but not circular muscles (trashing vs. telescoping movement)
3. pseudocoelom acts as hydrostatic skeleton and circulatory system
What is the Caenorhabditis elegans (Nematoda)?
- model research organism
- programmed cell death (1,090 somatic cells, 131 always dies leaving 959 cells)
What is Phylum Arthropoda (Ecdysozoa)?
Important characterists:
1. success related to body plan
2. exoskeleton made of chitin and protein
3. segments fused into functional units
4. extensive cephalization
5. sophisticated brain with 2 or 3 ganglia
6. gas exchange = gills tracheal system (blood not used for oxygen transport)
What is Subphyla Triolobita (anthropoda)?
- trilobites (flourished 500 myo)
- extinct early arthropods, bottom feeders, little specialization of body segments
What is Subphyla Chelicerata (Anthropoda)?
- spiders, ticks, scorpions, and mites
- 2 tagmata body plan = cephalothorax + abdomen
- 6 pairs of appendages
What make up Subphyla Myriapoda (anthropoda)?
- class diplopoda millipedes (2 pairs of legs per segment = herbivorous)
- class chilopodoa centipedes (1 pair of legs per segment = carnivorous)
What is Subphyla Hexapoda (anthropoda)?
- insects
- more species of insects than all other animal species combined
wings crucial to success (outgrowths of body wall) - large diversity of mouth parts –> predicts feeding habits –> all modified from same mouth segments
What are the two types of metamorphosis that Subphyla Hexapoda go through?
- Complete: 4 stages with adult and larval stages very different
- Incomplete: 3 stages with young resembling miniature adults
What is Subphyla Crustacea (arthopoda)?
- unique in that they have 2 pairs of antennae
- decapoda have 5 pairs of legs, the first modified into claws
- larvae of crustaceans are planktonic )which mole several times before reaching maturity)
What are the two important characteristics of deuterostomia?
- deuterostome development (anus forming before mouth)
- endoskeleton
What is phylum Echinodermata (deuterostomia)?
- sea stars, brittle stars, sea urchins, sand dollars, sea lillies, sea cucumbers
Important characteristics:
1. modified radial symmetry = 5 parts (secondary = larvae are bilateral)
2. cephalization absent
3. exoskeleton covered with spines and pedicellariae (pinchers)
What 2 things do phylum echinodermata not have?
- no brain (simple nervous system)
- no excretory organs (respiration and excretion by diffusion)
What are the 4 innovations of Phylum Chordata (deuterostomia)?
- notochord = single flexible rod
- dorsal hollow nerve cord
- pharyngeal slits
- postanal tail
- can see this fundamental body plan among vertebrates during the embryonic development
What is Subphylum Cephalochordata (chordata)?
- lancets
Important characters:
1. marine filter feeders
2. have all 4 innovations
3. gas exchange across body surface
4. usually sessile but can leave burrow and swim
What is Subphyla Urochordata (chordata)?
- tunicates
Important characteristics:
1. adult sessile with only pharyngeal slits
2. larvae tadpole-like exhibiting all 4 hallmarks\
3. closest living relatives of vertebrates
4. filter feeders with incurrent and excurrent siphon
What is Subphylum Craniates (chordata)?
Important characteristics:
1. cranium: protective bony or cartilaginous housing for brain (derived from ectodermal cells called the neural crest)
2. neural crest: embryonic cells that will disperse throughout the embryo contributing to the development of the skeleton, jaws, and teeth
What are Class Myxini (craniates)?
- hagfish
Important characteristics:
1. jawless, finless, marine fish that lack vertebrae
2. notochord and cartilaginous skull
3. essentially blind with a keen sense of smell
4. copious amounts of slime
What are vertebrates (chordates)?
- Have all chordate and craniate characteristics
- vertebral column (notochord replaced by bony or cartilaginous column of interlocking vertebrae)
- endoskeleton of cartilage or bone (most have 2 pairs of appendages)
- internal organs (liver, kidneys, endocrine glands, and heart with at least 2 chambers)
What is Class Petromyzontida (vertebrates)?
- lampreys
important characteristics:
1. lack of hinged jaw and true appendages
2. have a notochord and a rudimentary vertebral column
3. one of earliest diverging groups of vertebrates
What are Gnathostomes (jawed vertebraes)?
- hinged jaw develops from pharyngeal arches
- modification of existing denture
- allowed for predation
What are Chondrichthyes (Gnathostomes)?
- sharks, skates, and rays
- need to swim to maintain buoyancy and breathing
Importnat characteristics:
1. cartilaginous fish
2. sharks among earliest fish to develop teeth
What is the internal fertilization of Class Chondricthyes (gnathostomes)?
- oviparous = lay eggs
- ovoviparous = egg retained in female, no placenta
- vivparous = eggs develop in uterus, placenta nourishes young
What are the 3 living classes of bony fish?
- Actinopterygii (ray-finned fish)
- Actinistia (coelacanths)
- Dipnoi (lungfish)
What 4 features make bony fish different from Chondricythes (sharks)?
- bony skeleton
- operculum covers gills
- swim bladder for buoyancy
- slimy scales
What are class Actinopterygii (ray-finned fish)?
- 95% of all fish
- fins supported by thin, bony, flexible rays
What is the difference between ray-finned fish and lobe fins?
Lobe fins have skeletal expansions –> terrestrial tetrapods evolved from these fish
What are Actinistia (coelacanths)?
- believed extinct until 1938
- special joint in skill gives powerful bite
- swim bladder filled with oil instead of gas
- early lobe fish were fresh water organisms and had lungs but coelacanth lost them and returned to sea
What are Dipnoi (lungfish)?
- 3 genera with 6 species
- live in oxygen-poor freshwater both gills and lungs (will drown if unable to breathe air)
What is the origin of tetrapods (transition to land)?
- 4 limbs = tetrapod
- transition to land required adaptations for locomotion, desiccation prevention, and reproduction
- sturdy lobe-finned fishes gave rise to fish with four limbs
What is the Tiktaalik (fishapod)?
- non-tetrapod member of bony fish during devonian (375 mya)
- fins have thin ray bones for paddling like most fish, but also have sturdy (footlike) interior bones
- allowing to prop itself up in shallow water and use limbs for support and in most tetrapods
What are hox genes?
- evidence of tetrapod evolution based on genes
- Hox genes: regulate growth patterning to specify limb formation from the proximal to the distal direction (meaning from close to point of attachment to body, to terminal end of limb)
What are amphibians (tetrapods)?
- frogs, toads, salamanders, and caecilians
- successfully invaded land but must return to water to reproduce
- skin can absorb oxygen
- metamorphosis regulated by thyroid hormones
What are the 3 major orders of amphibians?
- Order Anura = frogs and toads
- Order Caudata = salamanders
- Order Gymnophions = caecilians
Why was the shelled egg so important (amniotes)?
- critical innovation
- development of a shelled egg that sheltered the embryo from desiccating conditions on land
- amniotic egg broke obligate tie to water
What are the 4 other tetrapod key innovations (amniotes)?
- desiccation resistant skin
- thoracic breathing
- water-conserving kidneys
- internal fertilization
What make up amniotes?
- reptiles
- birds
- mammals
What are class Testudines (amniotes)?
- turtles, tortises, and terrapins
- unchanged for 200 my
- hard protective shell (in most vertebrae and ribs fused to shell)
- lack teeth but have sharp beak
What is the gradual evolution of the turtle shell?
- over millions of years, rows of protective armor plates gradually fused together and also to the reptiles vertebrae (eventually creating a complete shell)
What is class Lepidosauria (amniotes)?
- lizards and snakes
- kinetic skull (movement of skull bones) with extremely mobile joints
- lizards have moveable eyelids and external ears while snakes do not
What is class Crocodilia (amniotes)?
- crocodiles and alligators
- essentially unchanged for 200 my
- 4 chambered heart
- teeth in sockets
- care for young
What kind of clade are reptila?
Monophyletic that include dinosaurs and birds
What are two classifications of dinosaurs?
- Class Ornithischia = bird hipped dinosaurs
- Class Saurischia = lizard-hipped dinosaurs
- legs of dinosaurs were positioned directly under the body
What is an Ornithischian dinosaur?
- bird hipped
- pubis bone points downward and toward the tail (backwords), parallel with the ischium, with a forward-pointing process to support the abdomen
- this makes a four pronged pelvic puncture
What is a Saurischian dinosaur?
- lizard hipped
- pubis points downward and toward the head (forwards)
- as in ancesteral lizard types
What is the origin of birds?
- derived from lizard-hipped dinosaurs (Saurischia)
- bird-hipped evolved independently many times (convergent evolution)
What are the Class Aves (bird)?
4 features unique to all birds (related to flight)
1. air sacs = efficient breathing
2. reduction of organs = single ovary, no urinary bladder
3. feathers = modified scales to keep birds warm and enable flight
4. lightweight skeleton = thin, hollow, honeycombed
What are air sacs in birds?
work to produce a unidirectional flow where air enters and exists the lung at the same rate
What are mammals?
- appeared about 255 mya
- evolved from amniote ancestors earlier than dinosaurs
- flourished after extinction of dinosaurs
- range of sizes and body forms unmatched
What are important characteristics of mammals?
- hair
- mammary glands that secrete milk
- teeth shape and size predicts feeding ecology
- vertebrates with specialized teeth
- enlarged skull
- chewing jaws
- some have horns and antlers
What is a ruminants stomach (mammals)?
some but not all mammals digest plants using symbiotic bacteria
What is order Monotremata (subclass prototheria)?
- platypus and echidnas
- lay eggs, lack placenta, poorly developed nipples
What is Clade Metatheria (marsupials) (subclass theria)?
- once widespread, now mostly in Australia
- opossum found in North America
- very underdeveloped young must make it to marsupium to finish development
What is Clade Eutheria (subclass theria)?
- Placental mammals
- long-lived complex placenta with prolonged gestation
What are primates (mammals)?
- primarily tree-dwelling species that evolved about 85 mya
- grasping hands with opposable thumbs
- large brain
- some digits have flat nails (not claws)
- complex social behavior and well-developed parental care
What are the two groups of primates?
Stepsirrhi and Haplorrhini
What are Strepsirrhini (primates)?
- bush babies, lemurs, loris
- wet noses, no fur at tip
- generally nocturnal and smaller-brained
What are Anthropoidea (primates)?
- Simians
- new world monkeys, old world monkeys, and apes
(dry noses, fully furred noses)
What are Haplorrhini: Infraorder Tarsiiformes (primates)?
- tarsiers
- small, nocturnal, and insectivorous
What are new world monkeys (primates)?
- 5 families in central and south america
- distinction in the nose (flat, narrow, and side facing nostrils)
- prehensile tails
What are old world monkeys (primates)?
- native to africa and asia
- most have tails (non prehensile)
- differ from apes by dentition shape
- many omnivorous
What are hominoids (primates)?
- gibbons, gorillas, orangutans, chimpanzees, and humans
- no tails, brachiation (swinging movement in trees), usually larger
- family hylobatidae = lesser apes or gibbons
- family hominidae = greater apes
What are the two subfamilies of Family hominidae?
- Subfamily Ponginae = orangutans
- Subfamily Hominonae = tribe gorillini (gorillas), Tribe Panini (chimpanzess), tribe homonini (humans and thier ancestors)
What is human evolution?
- about 6mya lineage split off from primate lineage (1 or 2 hominin species coexisting at same time)
- key characteristic was bipedalism –> resulted in many changes = spine sits underneath skull, broader pelvis, lower limbs larger
What are Australopithecines?
- widespread, at least 6 species, relatively small, facial structure and brain size similar to chimp
- regarded as the common ancestor of this group
What is a homo?
- increased brain size, stone tools
- homo sapiens (taller, lighter weight, slightly smaller brain capacity than homo neanderthalensis
What are the two hypothesis of human evolution?
- Out of Africa Hypothesis = H. sapiens evolved from Africa and spread from there to other regions
- Multiregional hypothesis = H. ergaster spread among different region and population differentiated seperately
