Exam 2

Be able to define what is meant by an essential element and be able to list all macronutrients and micronutrients.

• Essential Elements = element required by the plant to complete its lifecycle

• may not be necessary at every stage (e.g. required only for pollen)

• Macronutrients (required in high concentrations) = C, H, O, P, K, N, S, Ca, Mg

• Micronutrients (required in low concentrations) = Mo, B, Zn, Cu, Mn, Fe, Cl, Ni

Be able to describe how hydroponics is used to determine mineral deficiency symptoms.

1. multiple plants are grown in mineral-rich solutions without soil

2. the mineral being tested is removed from one of the plants to see if it is essential

Know the functions of the macronutrients as listed in class.

Carbon, Oxygen, Hydrogen = part of every organic molecule in every living thing

Nitrogen = proteins, amino acids, DNA/RNA; increases plant productivity

Potassium = opening/closing stomata

Calcium = middle lamella; area between 2 cell walls

Magnesium = chlorophyll synthesis; element that loses e-

Phosphorus = phospholipids, DNA/RNA, ATP

Sulfur = amino acids

Why do most plants generally tend to grow better in slightly acidic soils?

most minerals/nutrients are more soluble in acid soils (e.g. phosphorous not available in more basic soils)

What is cation exchange and how can it affect the availability of cations for uptake by plant roots?

Happens in the soil:

1. soil has a net (-) charge

2. potassium (critical) attracted to (-) charge and sticks → cannot reach the roots

3. pH is lowered; H+ [ ] increases

4. H+ competes with potassium for charges → potassium knocked off into soil water (H+ exchanged for potassium)

5. potassium available for plant roots

What is leaching and why are anions like nitrate (NO3-) more likely to leach through soils and end up in groundwater?

NO3- (anion) repelled by (-) soil charges

Leaching = NO3- flows through soil and get washed away (filter through the soil because they don’t bind to soil)

What is the Biological Nitrogen Fixation?

Nitrogen is converted to proteins

N2 → NH4+ → amino acids → proteins

• only prokaryotic organisms can do N fixation

Be able to describe the significance of root nodules. What benefit does the plant get?

root nodules are full of nitrogen-fixing bacteria → converts N2 → proteins

plants (e.g. leguminous) do this so they can get a lot of proteins

benefit: plants get N2

What benefit does the bacteria get? What types of plants are able to form root nodules?

benefit: bacteria gets sugars

Legumes can form root nodules

Be able to describe the significance of Mycorrhizae associations. What benefit does the plant get and what benefit does the fungus get?

Mycorrhizae (root-fungal association) = increases nutrient/water uptake by the host plant by using a larger volume of soil than roots can alone

fungus get sugar; plants get increased root surface area for more water absorption

Be able to list the four characteristics of a hormone.

1. Organic substances

2. Produce endogenously - plant makes it internally (synthesized)

3. Translocated - produced in one tissue, active somewhere else

4. Active in very low concentrations

Be able to define phototropism and be able to explain how auxin controls this developmental response.

Phototropism = bending of plants towards light source; response attributed to auxin

1. tip of plant shoot is producing auxin

2. auxin transported away from the light source

3. increase in auxin causes increase in plant cell size

4. shoot bends toward light source

Be able to describe the acid-growth hypothesis and the role of the proton pump (ATPase), expansin, and cell wall cleaving enzymes.

1. increase in auxin

2. H+ pump stimulated (ATPase)

3. decrease in pH of cell wall

4. expansin (protein) is activated = expands microfibrils of cell walls

5. increased space in cell wall

6. cell wall cleaving enzymes = cleaves fibers and loosens cell walls

Be able to describe the effects of increasing auxin concentration on plant growth (i.e. graph of growth versus auxin concentration for roots and shoots).

increased auxin leads to increased plant cell size

• roots are more sensitive to auxin increase compared to shoots (stems/leaves)

Be able to describe the polar (basal) transport of auxin

• auxin produced in apical meristem

• auxin moves toward base of plant

• auxin in shoot moves down; auxin in root moves up (cellular transport NOT gravity)

Be able to define apical dominance and know how auxin is involved in controlling apical dominance.

Apical Dominance = growth comes from apex/tip

remove apical bud → apical dominance released → replace with capsule with auxin → apical dominance is maintained

Know that auxins promote cell enlargement and root formation.

AUXINS PROMOTE CELL ENLARGEMENT AND ROOT FORMATION

What are adventitious roots and how are these promoted by auxin?

Adventitious Roots = roots produced in unusual places (e.g. stems, leaves); type of asexual reproduction

• auxin promotes root development

Know that cytokinins promote cell division.

CYTOKININS PROMOTES CELL DIVISION AND SHOOT FORMATION

Be able to describe the relationship between auxins and cytokinins in terms of controlling root and shoot formation in tissue culture.

1. take piece of tissue (sterile e.g. carrot tissue)

2. add essential elements, sugar, auxin, cytokinins (add correct ratio of auxin:cytokinins)

3. cells start to divide and enlarge

4. Callus (massive tissue) is formed

auxin > cytokinins in callus = root formation

cytokinins > auxin in callus = shoot formation (stems, leaves, etc.)

lesson: ratio of auxin:cytokinins determines whether roots or shoots are formed

Be able to define senescence. Know that cytokinins delay senescence.

Senescence = irreversible physiological changes that ultimately lead to death of an organ/organism

cytokinins delays senescence

Senescence of an organism:

1. hormonal signals that cause the plants to produce seeds

2. parent plant dumps resources into seeds

3. parent plant undergoes senescence

Senescence of an organ (e.g. leaves):

1. trees grow throughout spring/summer

2. tree wants to seal up for winter and drops leaves in the fall

3. leaves undergo senescence

Senescence of a fruit: rotting (due to a decrease in cytokinins)

Know that one of the main effects of gibberellins is to promote internode elongation.

gibberellins promotes internode elongation (shoot size increases) and seed germination

Be able to describe the relationship between gibberellins and dwarfism.

mutation/defect in gibberellin production → internodes do not elongate → dwarf plant

many dwarf plants don’t have/cannot produce gibberellins

Be able to define bolting and describe how gibberellins affect bolting.

Bolting = massive internode elongation

addition of gibberellins → bolting

Know how gibberellins can be used commercially to increase the size of fruits (e.g. grapes).

gibberellins treatment increases fruit size

gibberellins increase auxin content → increase the absorption of nutrients → increases fruit size

Know the sequence of events leading to seed germination and how gibberellins are involved (i.e. Seed exposed to water, embryo makes gibberellin, gibberellin stimulates aleurone layer to make α-amylase, α-amylase breaks down starchy endosperm, embryo uses glucose as an energy source for growth).

1. add water to seed in ground

2. embryo produced gibberellins

3. gibberellins go to aleurone layer

4. aleurone layer produces α-amylase

5. α-amylase breaks down starchy endosperm into glucose

6. embryo uses glucose as an energy source for growth

Be able to describe the relationship between gibberellins and abscisic acid during seed germination and bud break (release of bud dormancy).

Abscisic Acid = inhibits seed germination

in seeds and tree buds:

AA > G - seeds/buds are dormant (fall/winter)

G > AA - seeds germinate; buds “break” (spring)

Be able to describe the phenotype of vivipary mutants and know that these mutants lack abscisic acid.

Vivipary Mutants = cannot produce abscisic acid → seeds don’t go dormant → early germination occurs

Know that abscisic acid affects the closing of the stomata in plants experiencing a water deficit around the roots.

ABA produced in the roots → signals stomata to close under dry conditions

Define senescence. Know that leaf abscission (drop) and fruit ripening are types of organ senescence.

Senescence = irreversible physiological changes that ultimately lead to death of an organ/organism

Leaf Abscission = leaf shedding, fruit ripening

Know that ethylene is a gaseous hormone and that it promotes leaf senescence (leaf drop), flower senescence, and fruit senescence (ripening). Also know why the phrase “one bad apple spoils the whole barrel” has some scientific validity. Know that ethylene is autocatalytic (i.e it promotes its own synthesis)

Leaf Senescence + Ethylene = one plant is genetically altered so that it cannot detect ethylene and the other is unaltered → both exposed to ethylene → unaltered plant exhibits leaf senescence

Flower Senescence + Ethylene = ethylene promotes flower senescence → example: one flower treated with mineral to prevent ethylene detection and the other is not → flower without treatment undergoes flower senescence

Fruit Senescence = ethylene promotes flower senescence → some tomatoes genetically altered to slow down ethylene production and some are unaltered → unaltered tomatoes undergo fruit senescence

“one bad apple spoils the whole barrel” = ethylene is a gas → ethylene is produced from rotten apple and goes to other apples in barrel → other apples produce ethylene → ripening much faster

Be able to define gravitropism and thigmotropism and know that auxin is involved in these responses.

Gravitropism = (in roots) curving/bending in response to gravity; if root is not growing vertically downward → auxin accumulates in the lower parts of the root → cell elongation → root bends in the direction of gravity.

Thigmotropism = curving/bending of plants due to touch

Be able to describe thigmomorphogenesis and the evolutionary advantage of this developmental response (e.g. How might this response help a plant survive growing in windy environments like on the side of a cliff?).

Thigmomorphogenesis = stunted growth in response to continuous touch

• strengthening tissue, especially xylem, is produced to add stiffness to resist the wind's force

Know the 8 common features used to distinguish animals from other groups

1. Animals are multicellular, heterotrophic, eukaryotes that ingest/digest food

2. Animals lack a cell wall

3. Move at some point in their life

4. Animals have Hox genes (regulatory genes)

5. Have structural proteins (e.g. collagen)

6. Most have nervous/muscle tissue

7. Most produce sexually

8. Many have 1 larval stage

Prokaryote vs. Eukaryote

Prokaryote = no nucleus/organelles

Eukaryotic = membrane bound nucleus/organelles; more structure/organization

Unicellular vs. Multicellular

Unicellular = Protozoans (single-celled animal-like organisms); e.g. Paramecium

Multicellular = Metazoans (animals with multiple cells); e.g. beetles

Autotroph vs. Heterotroph

Autotroph (plants) = produces energy through photosynthesis; energy is absorbed

Heterotroph (animals) = eat other organisms to get nutrients; energy is ingested/digested

What are HOX genes and who has them?

involved in the development of the body plan in animals

How can each kingdom be classified?

Archaea & Bacteria = Prokaryotes

Protista = Protozoa + Eukaryotes

Plantae = Autotrophic + Metazoa + Eukaryotes

Fungi = Absorptive + Heterotrophic + Metazoa + Eukaryotes

Animalia = Ingest/Digest + Heterotrophic + Metazoa + Eukaryotes

Know the general ways that animals can reproduce (sexual vs. asexual) and what ploidy (diploid or haploid) gametes and fertilized eggs would be.

Most animals reproduce sexually

Gametes (n) - haploid

Fertilized eggs (2n) - diploid

How are animal body plans useful for developing animal phylogenies? (hint: think symmetry)

Asymmetrical; Spherical; Radial; Bilateral

Cephalization

**Asymmetrical = no symmetry; random assortment (e.g. many sponges)

Spherical Symmetry = any plane passes through the center and divides the body into identical image halves (e.g. most protists, NOT in animal kingdom)

**Radial Symmetry = 2+ planes pass through the longitudinal axis and create identical halves (e.g. anemones - coral, jellyfish)

**Bilateral Symmetry = one plane passes through organisms and divides it into a right/left half (most common)

Cephalization = differentiation of a head (e.g. nervous tissue, sense organs, mouth)

Animal body plans continued:

Anterior-Posterior

Dorsal-Ventral

Left-Right

Anterior-Posterior = transverse plane

Dorsal-Ventral = frontal plane (front/back)

Left-Right = sagittal plane

Understand the general developmental patterns that animals undergo. This includes cleavage, the development of the blastula and gastrulation.

zygote goes through cleavage → 8-cell stage → blastule (big hollow sphere) → gastrulation (one side of embryo goes inward) → gastrula

Define the different layers of embryonic tissues of the gastrula

1. Ectoderm = outer part of the body (e.g. skin)

2. Blastocoel = in between endoderm and ectoderm; can become mouth

3. Endoderm = inside tissue layer (e.g. lines digestive tract)

4. Archenteron = gap inside the gastrula

Be able to explain the difference between determinant and indeterminate cleavage and spiral and radial cleavage.

determinate cleavage = fate of each cell is decided early; can track what they will lead to (e.g. liver tissue, skin, etc.)

indeterminate cleavage = each cell retains potential to become an entire embryo; cannot track

spiral cleavage = diagonal to midline

radial cleavage = perpendicular/parallel to midline

Know the three different germ layers seen in animals and which animals have which.

1. Ectoderm = outer part of the body (e.g. skin)

2. Endoderm = inside tissue layer (e.g. lines digestive tract)

3. Mesoderm = forms muscle and most internal organs

Define the terms diploblastic, triploblastic, acoelomate, psuedocoelomate, coelomate.

Diploblastic = animals have only an ectoderm and endoderm (e.g. jellies, corals, comb jellies)

Triplobastic = mesoderm layer included

Acoelomate = animals without coelom

Psuedocoelomate = has one mesoderm and one endoermal

Coelomate = has mesoderm and hydrostatic skeleton

Be able to explain how the body cavity of different animals developed (if they have one) by defining schizocoelous and enterocoelous coelom formation.

Schizocoelous = solid mass of mesoderm splits down center - protostomes (e.g. molluscs, annelids)

Enterocoelous = mesoderm buds from archenteron, forms cavity - deuterostome (e.g. echinoderms, chordates)

Define and explain the difference between a deuterostome and a protostome.

Protostome = 1st opening is mouth (most animals); invertebrates (e.g. annelids, molluscs)

Deuterostomes = 1st opening is anus; vertebrates and one invertebrae group: starfish (e.g. echinoderms, chordates)

Define what a lophophore and a trochophore are and what ecdysis is.

Lophophore = ciliated ring (e.g. ectoprocta)

Trochophore = larval phase (e.g. annelida)

Ecdysis = secrete hard exoskeleton

Phylum - Porifera

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

Reproduction? Advantages/Disadvantages?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? sponges

Body Plan = asymmetrical, no true tissues

Development = not a protosome/deuterostome

Tissue Organization = no true tissue

Form of Locomotion = larvae are motile when dispersed from parent sponge

Reproduction = asexual reproduction = fragmentation (body breaking into parts); budding (producing gemmules - resistant cells that can survive rough water conditions); regeneration

sexual reproduction = ‘sequential hermaphroditism’ - both male/female parts; choanocytes of female sponges pick up released sperm and become amoeba-like cells which transport sperm to egg

Direct or Indirect Development = direct/indirect development = N/A

Describe their digestive/alimentary tract = no digestive/alimentary tract; absorption

Circulatory system = no circulatory system

Phylum Cnidaria

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

General Body Parts?

How do they feed? What do they eat?

Reproduction? Advantages/Disadvantages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? 1st eumetazoan: corals, anemones, jellies, hydras

Body Plan = diploblastic; radially symmetrical (sessile polyp OR motile medusa)

Development = protosome; one opening

Tissue Organization = diploblastic - no coelem, no mesoderm; nerve net - allows them to detect/respond to stimuli; basic nervous system (no brain); contracting cells between gastrovascular cavity and epidermis

Form of Locomotion = motile medusa stage

General Body Parts = mouth, cilia, NO anus

How do they feed? What do they eat? capture food with ring of tentacles around the mouth; cnidocytes (special cells) that contain cnidae (nematocysts = stinging cell) which are launched from body to harpoon prey; instant

Reproduction? Advantages/Disadvantages? asexual reproduction (budding) to produce medusa; sexual reproduction between medusa to produce e planula (larva)

How would you describe their digestive/alimentary tract? internal body cavity with one opening

Do they have a circulatory system? If so, what type? N/A

Which species of the Cnidaria phylum are polyps, medusa, or both?

Polyp - corals, anemones

Medusa - jellyfish (scyphozoans, cubozoans)

Both - hydrozoans alternate

What do corals exhibit?

Mutualism = symbiotic relationship where two organisms co-exist and benefit from each other

Example of a symbiotic relationship

Zooxanthellae = photosynthetic brown algae that grow within polyp tissue

turns light and CO2 into O2 and sugar

provides food for coral; coral provides a home

Corals build 3 types of reefs

1. Fringing = grows close to shore

2. Barrier = grows close to shore BUT has a lagoon that separates it from the shore

3. Atoll = ring of coral that surrounds a lagoon; often grows on a submerged mountain/volcano

What distinguishes Ctenophores from Cnidaria?

lack cnidae but have sticky tentacles to capture prey

Phylum Platyhelminthes

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

General Body Parts?

How do they feed? What do they eat?

Reproduction? Advantages/Disadvantages?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? flatworms (tapeworms, planarians, flukes)

Body Plan? bilaterally symmetrical; triploblastic

Development? protosome

Tissue Organization? acoelomate; no body cavity; ectoderm, endoderm, mesoderm

Form of Locomotion? cilia on their ventral (belly surface)

General Body Parts? mouth, cilia, NO anus

How do they feed? What do they eat? use ciliated pharynx to feed

Reproduction? Advantages/Disadvantages? asexual reproduction through fission = pinch off in half and regenerate ; hermaphrodites

Direct or Indirect Development? If indirect, which larval stages? direct development

How would you describe their digestive/alimentary tract? gastrovascular cavity

Do they have a circulatory system? If so, what type? N/A

Phylum Platyhelminthes - planarians

Free living or Parasitic?

Free living

Phylum Platyhelminthes - flukes

Free living or Parasitic?

Parasitic - in humans, livestock

causes disease in humans

Phylum Platyhelminthes - tapeworms

Free living or Parasitic?

Parasitic - live in vertebrates

anchors itself to intestine and absorbs nutrients; does NOT need mouth; good at reproducing

Phylum Rotifera

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

General Body Parts?

How do they feed? What do they eat?

Reproduction? Advantages/Disadvantages?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

Body Plan? bilaterally symmetrical; triploblastic

Development? protosome

Tissue Organization? pseudocoelomates (body cavity present)

Form of Locomotion? crown of cilia around mouth to move water

General Body Parts? mouth, cilia, anus

How do they feed? What do they eat? eat dead, unicellular algae

Reproduction? Advantages/Disadvantages? unusual; species is mostly female; parthenogenesis (asexual) = females produce female offspring from unfertilized egg (similar to cloning)

Direct or Indirect Development? If indirect, which larval stages? direct

How would you describe their digestive/alimentary tract? gastrovascular cavity; alimentary canal = 1st mouth, 2nd anus (protosome) separates mouth and anus

Do they have a circulatory system? If so, what type? N/A

Phylum Ectoprocta

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

General Body Parts?

How do they feed? What do they eat?

Reproduction? Advantages/Disadvantages?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? bryozoans

Body Plan? bilaterally symmetrical; triploblastic; first species to have true coelom

Development? protosome

Tissue Organization? coelomate

Form of Locomotion? live in sessile colonies (attached to something)

General Body Parts? hard exoskeleton; lophophore = crown of ciliated tentacles around mouth

How do they feed? What do they eat? tentacles capture food

Reproduction? Advantages/Disadvantages? hermaphroditic; heterozoids (ovicells) produce eggs, testes produce sperm

Direct or Indirect Development? If indirect, which larval stages? direct; zooids = segment of whole animal, takes on different functions

How would you describe their digestive/alimentary tract? gastrovascular activity; alimentray canal

Do they have a circulatory system? If so, what type? N/A

What are Autozooids and Kenozooids?

Autozooids = feeding zooids, make up bulk on colony

Kenozooids = serve as stolons, attachment discs/defensive spines

Phylum Brachiopoda

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

How do they feed? What do they eat?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? lamp shells NOT bivalve molluscs

Body Plan? bilaterally symmetrical; triploblastic

Development? protosome

Tissue Organization? coelomates

Form of Locomotion? pedicle = anchors them to substrate (ground, rock); different from molluscs

How do they feed? What do they eat? suspension feeders

Direct or Indirect Development? If indirect, which larval stages? direct

How would you describe their digestive/alimentary tract? gastrovascular cavity; alimentary canal; lophophore (different from mollusc)

Do they have a circulatory system? If so, what type? N/A

Difference between Brachiopods and Bivalve Mollusc?

Brachiopods = symmetrical valves enclose body dorsally and ventrally

Bivalve Mollusc = valve encloses body laterally and are asymmetrical across midline

Phylum Mollusca

What are they?

Body Plan?

Development?

Tissue Organization?

Form of Locomotion?

General Body Parts?

How do they feed? What do they eat?

Direct or Indirect Development? If indirect, which larval stages?

How would you describe their digestive/alimentary tract?

Do they have a circulatory system? If so, what type?

What are they? snails, bivalves, cephalopods

Body Plan? bilaterally symmetrical; triploblastic; ‘soft-bodied’ (some have hard shell); **3 Main Parts = foot, visceral mass (everything), mantle (lined shell)

Development? protosome

Tissue Organization? coelomates

Form of Locomotion? varies by class

General Body Parts? radula = ‘sandpaper’ feeding apparatus; scrapes algae off rocks, anus, cilia

How do they feed? What do they eat? using their radula

Direct or Indirect Development? If indirect, which larval stages? direct

How would you describe their digestive/alimentary tract? full digestive system (gastrovascular cavity + alimentary canal); lophophore

Do they have a circulatory system? If so, what type? varies

Phylum Mollusca - Chitons (polyplacophorans)

Body Plan?

Form of Locomotion?

Circulatory System?

Body Plan? shell divided into 8 dorsal plates (able to flex/change shape); stick very tightly to rocks

Form of Locomotion? move slowly using their foot

Circulatory System? none

Phylum Gastropods

Body Plan?

Form of Locomotion?

Reproduction?

Digestive/Alimentary Tract?

Circulatory System?

Body Plan? undergoes torsion = twisting visceral mass

Form of Locomotion? move using their foot

Reproduction? some hemaphroditic; some male or female; some release gametes in water and eggs fertilized internally; some can act as male and female at same time

Digestive/Alimentary Tract? use radula and masta

Circulatory System? yes - heart, “blood”, simple lung, etc. ; nudibranch (naked gill) = gills cover dorsal body surface; gills housed in mantle cavity

Phylum Bivalves

Defining feature?

Feeding?

Giant Clams -

Reproduction?

Defining feature? 2 shells

Feeding? suspension feeders - cycle water through mantle with siphons; food gets trapped on gills; cilia moves food to mouth

Giant Clams - colorful, mantle pushed out the shell to show off

Reproduction? internal fertilization

Sponges, Cnidaria, and Ctenophores

1. What makes a sponge an animal? What are the common features sponges share with choanoflagellates?

2. Know the general parts of the sponge and what they do.

3. Understand the general ways sponges reproduce.

4. What are the general body forms that cnidarians may have? Do all cnidarians exhibit both body forms?

5. Understand the generalized life cycle of hydrozoans.

6. Describe the symbiotic relationship between some corals and algae. What are the benefits/costs to each organism?

7. How do cnidarians sting their prey?

8. What distinguishes Ctenophores from Cnidaria?

1. multicellular, heterotrophic, lack cell wall, produce sperm; both filter feeders (choanocytes - sponge cells and choanoflagellates)

2. choanocytes: little flagella for feeding

3. asexually, fragmentation (budding), gemmules = resistant cells that can survive under harsh conditions, spore-like gemmules = experience dormancy during winter; sperm released into water and picked up by female; motile larva settles and develops into adult

4. 2 forms: sessile polyps = attached to something, medusa = free moving

5. alternate between polyp and medusa; asexual: budding zygote, larvae → developing polyp; sexual: sperm released into water

6. Zooxanthaie

7. ring of tentacles around their mouth, specialized cells with cnidae to harpoon prey

8. Ctenophores - no cnidae but have sticky tentacles used to capture prey

Platyhelminthes

1. What advantages does a flatworm have by being flat?

2. Many species are parasitic, what are the advantages/disadvantages of such a lifestyle?

1. move faster, hide from predators, nutrient/gas exchange is easier+efficient

2. Advantages - absorb nutrients from host, stay sedentary, reproduction is easy; Disadvantages - cannot survive without a host

Rotifera

1. Describe parthenogenesis and what the potential benefits/costs may be associated with this form of reproduction.

1. Parthenogenesis = females produce female offsprings from unfertilized eggs (asexual reproduction)

Benefit: numerous offspring without taking time+energy

Cost: lack of genetic diversity

Ectoprocta

1. Describe how ectoprocts are made up of specialized ‘zooids’.

1. Zooids - multicellualar animals that have different functions (hemaphroditic)

Autozooids = feeding zooids

Kenozooids = store nutrients in colonies (act as attatchment)

Heterozooids = ovicells produce eggs, testes produce sperm

Mollusca

1. What are the common features of the four mollusc classes discussed in class? What separates them? Describe the function/appearance of the foot, visceral mass, shell and mantle in each group.

2. What do giant clams and corals have in common?

1. see other flashcards

2. symbiotic relationship with zooxanthaiae

   • clams provide habitat; zooxanthaiae provide sugar and oxygen

Physiology concepts

1. How do cells communicate with one another?

2. What is an open circulatory system? How is it different from a closed circulatory system? What are the advantages of having a closed system?

1. 4 ways

   1. Gap Junctions = connexins form connexon (channel) between two cells → channel can be opened/closed which allows small molecules and signals to pass

   2. Contact-Dependent Signals = direct contact and local cell-to-cell communication; CAMS (contact adhesion molecules) = connects proteins in different cells, used to send signals from cell to cell

   3. Autocrine/Paracrine Signals = ligands (chemicals) released from one cell and diffused through extracellular fluid; Autocrine - act on the same cell that released ligand, Panacrine - act on nearby cells (e.g. histamine)

   4. Long Distance Communication = Hormones - Endocrine System = hormones enter blood and travel to act on cells with receptor, Exocrine System = release secretions into ducts that lead to target cell (NO blood);;; Neurotransmitters = electrical signals are used, very fast;;; Neurohormones = released by neurons into blood

2. Open = blood not enclosed in blood vessels and pumped into cavity, does not use much energy;;; Closed = blood contained in blood vessels, always circulating from heart