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