Objective questions and answers

  1. Which monophyletic group contains fungi and animals?
  • Fungi and animals are monophyletic; their group is Opisthokonta (ones with flagella in back).
  1. What is it about fungal infections in humans harder to treat than bacterial infections?
  • We are so closely related to fungi that anything that affects fungi negatively will affect us negatively.
  1. How do fungi eat?
  • Absorption using their hyphae
  1. What are the two growth forms exhibited by fungi?
  • Unicellular (yeasts) and multicellular
  1. What are hyphae and septa? Coenocytic hyphae?
  • Hyphae: each of the branching filaments that make up the mycelium of a fungus
  • Septa: “cross walls” of hyphae. Divides hyphae into cells. Septa are usually perforated by pores, so some things are able to get through
  • Coenocytic hyphae = no septa.
  1. Describe what is meant by EMF and AMF.
  • EMF = Ecotomycorrhizal fungi (grows on the outside of a plant)
  • AMF = Arbuscularmycorrhizal fungi (grows into the roots of a plant)
  1. How do fungi affect plants?
  • Parasitic relationships, symbiotic relationships, etc.
  1. Where does digestion take place in fungi?

Outside of the body. Thefungusbreaks down the complex material by secreting digestive enzymes throughtheircell wall that willdigestthe complex organic compounds and convert them into simple molecules that can readily be transported throughtheircell walls.

  1. Give 4 examples of mutualistic fungi.
  • Mycorrhizal: 1) arbuscular (AMF) and 2) ectomycorrhizal (EMF)
  • Ants farming fungus
  1. Saprophytic fungi: eats dead things
  1. What is the role of fungi in the carbon cycle?
  • Break things down that are difficult for other organisms to break down; cellulose and lignin.
  1. What are some ways that fungi benefit humans?
  • FOOD <3, medications, beer and wine, decomposers, etc.
  1. Give examples of how fungi act as parasites or pathogens.
  • Ringworm
  • Athletes foot
  • Cordyceps fungi
  • Lots of plant diseases (Dutch Elm Disease and Chestnut Blight)
  1. What is a spore? Plasmogamy? Dikaryotic? Karyogamy?
  • Spore: part that disperses to get to a new location to start a new body.
  • Plasmogamy: hyphae meet from two different individuals (recognize by pheromones), they join, and plasmogamy happens. The two cytoplasms mix together.
  • Dikaryotic: two separate nuclei in a single cell
  • Karyogamy: two nuclei fuse and you have a diploid nucleus

Next step after this is meiosis, which turn into haploid cells which can then be spores and start the cycle all over again!!!

  1. Give examples or characteristics of the six major groups of fungi.
  • Microsporidia – small, parasitic
  • Zygomycetes – molds
  • Chytrids – flagella
  • Glomeromycota – lots of AMF
  • Basidiomycetes – EMF, most mushrooms we eat are in this group, big colorful ones in forest, club fungi, yeasts
  • Ascomycota – truffles, sac fungi, lichens, yeasts

Remember them in this order and give examples of each that will help you distinguish them from each other.

  1. When did animals first show up in the fossil record?

600mya

  1. Why is the Cambrian Explosion significant for animal diversity?

550mya this occurred, higher oxygen levels may have caused this. A lot of the diversification today came from this.

  1. What are key traits for animals?

Multicellular

Mobility

Heterotroph

Muscles and nerves

Digest food internally

  1. In a phylogeny of animals, what is the outgroup? Most basal group?

Outgroup is Choanoflagellates (most closely related to animals). Most basal group is sponges (Porifera).

  1. What are key characteristics of sponges?

Sessile

Live in aquatic systems

They filter feed; they are suspension feeders

  1. What is the difference between diploblasts and triploblasts? At which point on the phylogenetic tree did each trait evolve?

Diploblasts only have two germ layers (ectoderm and endoderm) while triploblasts have three germ layers (ectoderm, endoderm and mesoderm). Ctenophores and Cnidarians are diploblasts, and the rest below are triploblasts.

  1. Which groups are radially symmetrical?

Ctenophores and Cnidarians have radial symmetry

All below have bilateral symmetry EXCEPT echinoderms

Side note: sponges are not symmetrical at all and don’t have organized tissue.

  1. What is the advantage of bilateral symmetry?

Central nervous system development is linked to bilateral symmetry (brain, and other important things). It enables effective movement in purposeful and intentional directions for the animal and more

  1. Which animal phylum is the most speciose?

Arthropods

  1. What are the challenges associated with transitioning from water to land?

Needed to be able to:

  • Exchange gases
  • Avoid drying out
  • Hold up their bodies under their own weight

Side note: the adaptations they developed in order to do these things are:

High surface area to volume ratio (increases efficiency of gas exchange across surface in moist environments)

Gills or other respiratory structures located inside body (minimizes water loss)

Waxy layer (minimize water loss)

Desiccation-resistant eggs (keeps moisture in eggs)

  1. What are the differences between protostomes and deuterostomes?
  • Protostomes develop mouth before anus. Blocks of mesoderm hollow out to form the coelom
  • Deuterostomesdevlop anus before mouth. Pockets of mesoderm pinch off to form coelom
  1. Which three traits are used to identify an animal as a lophotrochozoan?
  • Lophophore
  • Throcohpore larva
  • Spiral cleavage
  1. What trait distinguishes ecdysozoans from lophotrochozoans?

Ecdysozoans grow by molting and lophotrochozoans grow by extending the size of their skeleton and continuously growing when conditions are good

  1. What traits do you associate with rotifers? Platyhelminthes? Annelids? Mollusks?
  • Mollusks have a muscular foot, visceral mass and mantle. They also have a radula (feeding structure that functions like a rasp or file, sharp plates). The mollusks lineages are bivalves (clams and mussels), gastropods (slugs and snails), chitons (mollusks with plated dorsal shells), and cephalopods (squids and octupuses)
  • Rotifers live in damp soils and marine and freshwater environments. They have a coelom and are less than 1mm long. Although they are arelophotrochozoans, they have neither a lophophore nor a trochophore.
  • Platyhelminthes are flatworms. They have a broad, flattened body shape, are unsegmented, lack a coelom.
  • Annelids are segmented worms.
  1. What are the key parts of a mollusk? What is a radula?

The three key parts of a mollusk are the muscular foot, visceral mass and mantle. A radula is a feeding structure mollusks use that functiosn like a rasp or file. Sharp plates scrape material so that it can be ingested.

  1. What are the four groups of molluscs?

Bivalves (clams and mussels), Gastropods (slugs and snails), Chitons (mollusk with plated dorsal shells), and Cephalopds (squids and octopuses)

  1. What traits do you associate with each group?
  • Bivales: clams and mussesls. Have a protective calcium carbonate shell with two parts that is hinged and closes using muscles attached to the valves. All bivalves can sense gravity, touch and certain chemicals. Most are suspension feeders. Only mollusks without a radula.

  • Gastropods: slugs and snails. Named for a large muscular foot on their ventral side
  • Chitons: mollusk with plated doral shells. Have a radula.
  • Cephalopods: squids and octopuses. Well deveopled head, foot that is modified to form long, muscular tentacles. Most have large brains. Giant squid included here. Have a radula and a beak
  1. How do ecdysozoans grow?

By molting

  1. What are the four main ecdysozoan phyla?

Arthropoda

Nematoda

Onychophora

Tardigrada

  1. What traits do you associate with Onychophorans? Tardigrades? Nematodes?

Onychophorans: segemented body and limbs but no exoskeleton or jointed appendages. Also called velvet worms. Small, caterpillar-like

Tardigrades: segmented body and limbs but no exoskeleton or jointed appendages. Also called water bears. Microscopic animals.

Nematodes: roundworms. Unsegmented worms that have a tube-with-a-tube body plan and no appendages

  1. What are the three main groups within Arthropods?

Chelicerata

Myriapoda

Insecta

  1. What are the three traits associated with arthropods?

Jointed appendages

Chitinous exoskeleton

Segmented bodies