Animals Test 1

BIOL2030 Test 1 Material

Who is Carolus Linneaus?

developed our current scheme of classification that is based on morphology, has a hierarchal taxnomoic framework, and uses binomial nomenclature

What is phylogeny?

history of development of species or other group

What are characters?

organismal features used to construct a phylogeny (or evolutionary tree)

what is homology

character similarity resulting from common ancestry

what is fusiform

a body shape common to many aquatic animals characterized by being tapered at both the head and the tail

what is homoplasy

non-homologous character similarity, misrepresents common ancestry

what are cladistics

evolution of information for tree building and classification

what is a cladogram

phylogenetic diagram based on cladistic analysis

what is a clade

group of organisms that includes most recent common ancestor and descendents of that ancestor

what is polarity (in terms of phylogeny)

ancestral/descendant relationships among different states of character (e.g. presence or absence of vertebral column)

what is outgroup comparison

examines polarity of a character state

what is comparative morphology

shapes and sizes of organismal structures including developmental origins, taken from living and fossil record; e.g. skull bones, limb bones, scales, feathers

what is comparative biochemistry

gene and protein sequencing of living and some fossil material; e.g. mtDNA, rRNA

what is comparative cytology

numbers, shapes, and sizes of chromosomes and associated material, from living matter only

What are the five levels of organization within animal and animal-like groups

A. protoplasmic level of organization

B. cellular level of organization

C. cell-tissue level of organization

D. tissue-organ level of organization

E. organ-system level of organization

describe protoplasmic level of organization

all life functions within a single cell, differentiated organelles perform specific functions

describe cellular level of organization

aggregation of cells exhibiting functional differentiation,, division of labour between cells (e.g. reproduction, nutrition)

describe cell-tissue level of organization

aggregation of cells into tissues, definite patterns/layers; e.g. cnidaria

describe tissue-organ level of organization

aggregation of tissues into organs, organs made up of more than one kind of tissues, parenchyma and stroma; e.g. platyhelminthes

describe organ-system level of organization

organs work together as a system to perform a function, systems associated with basic body functions

what are the 11 organ systems observed within animals

digestive, circulatory, respiratory, immune, skeletal, endocrine, excretory, nervous, integumentary, reproductive, muscular

which organs work together to constitute the digestive system

gastrointestinal (GI) tract: oral cavity, pharynx, oesophagus, stomach, intestine; accessory digestive organs: salivary glands, liver, gallbladder, pancreas

what is tissue

an organization of like cells; the fundamental structure of which animal organs are composed

what are the four types of tissue

epithelial, connective, muscular, nervous

what is epithelial tissue

sheets of cells that cover an external or internal surface

what is simple squamous epithelia, draw it

flattened cells with broad and flat shape, one cell layer; facilitates movement of gases and other molecules (easier to traverse simple flattened cells)

what is simple cuboidal epithelia, draw it

short, box-like cells (one layer of square cells); active secretory or absorptive functions/transport usually through ATP consumption

what is simple columnar epithelia, draw it

tall elongated cells (rectangles); often associated with highly absorptive surfaces (e.g. intestinal tract)

what is stratified squamous epithelia, draw it

layered cells to withstand mild mechanical abrasion; basal cells push upward, constantly reproducing through mitosis, pushing existing cells towards the surface and flattening them; built to slough off dead cells and withstand abrasion

what is transitional epithelia, draw it

stratified but specialized to accommodate stretching (urinary tract, bladder); depending on when you take a cross-section sample it will look different

what is connective tissue

diverse group of tissues specialized to bind and support other tissues

what is muscular tissue

specialized for voluntary and involuntary movement of various organs

what is nervous tissue

specialized for reception and conduction of stimuli and impulses

what are the two types of body fluids (noncellular components)

intracellular: within cells, cytoplasm

extracellular: outside cells (two types: blood plasma - fluid portion of blood outside cells; interstitial fluid - occupies space surrounding cells)

what is interstitial fluid

essentially blood plasma, blood plasma leaks between cells and becomes interstitial fluid, it is recollected and put back into cells

what are extracellular structural elements

supportive material: loose connective ‘tissue’, cartilage, bone, cuticle

what are the different types of body symmetry

asymmetry, spherical symmetry, radial symmetry, bilateral symmetry

what is asymmetry

no body axis and no plane of symmetry (e.g. unicellular eukaryotes (amoeba) and poriferans (sponges)

what is spherical symmetry

any plane passing through center divides the body equally; found only in unicellular eukaryotes (radiolarans)

what is radial symmetry

divided equally by more than two planes passing through the longitudinal axis (head to tail); body has general form of a cylinder (E.g. polyps, some sponges); some forms are modified like starfish which is pentaradial from a top down view

what is bilateral symmetry

body parts oriented around a single anterior to posterior axis; division along the sagittal plane results in two equal halves; associated with cephalization; animal usually moves head first so it confronts environment first; majority of animals (starting with flatworms)

what is the coelem

fluid filled cavity between outer body wall and gut that enables internal organs to grow larger and become more sophisticated (because the fluid cushions internal organs, preventing injury); act as a hydrostatic skeleton, providing support for soft-bodied animals

what are the three germ layer types and what do they make

ectoderm: skin

endoderm: gut

mesoderm: most organs

what is acoelomate, draw it

no true coelem (i.e. no body cavity); region between gut and ectoderm occupied by parenchyma/mesoderm; e.g. flatworm

what is a pseudocoelomate, draw it

possess a pseudocoel, no cellular membrane derived from the mesoderm; e.g. roundworm

what is coelomate, draw it

true coelem lined with peritoneum (Arises from the mesoderm and forms a lining which surrounds organs/gut/structures that have grown in the coelem); e.g. earthworm

describe unicellular eukaryotes’ complexity

apparently simple but actually as complex as any other animal; i.e. a single cell capable of feeding/digesting, locomotion, ‘behaving’, and reproducing; possess organelles not generally found in metazoan cells

how are eukaryotic cells important

ecologically and economically: primary producers, role in decomposition, human/animal health

how do unicellular eukaryotes fit into classification

paraphyletic group: most recent common ancestor is also the ancestor of plants, animals, and fungi (hence the group does NOT include all the descendants of the common ancestor)

what are the three ways unicellular eukaryotes can move?

ciliary motion, flagellar motion, amoeboid motion

describe ciliary motion, draw it

Cilia: hair-like outgrowths from surface of cell; ciliary beating: a circular motion with 2 components, the power stroke (stiffened cilia propel water) and the recovery stroke (cilia bend towards body to reduce resistance); movement of organism is achieved by synchronized beating of cilia (metachronal beating); cilia beat obliquely/at an angle so the organism moves in a spiral

describe flagellar motion

Flagella: whip-like outgrowths from surface of cell; a flagellum propels water parallel to the main axis of the flagellum, bending in opposite directions along the flagellum to produce a wave action along the flagellum

describe amoeboid motion, draw it

Pseudopodia: a free-form projection of the cell; classic amoeboid locomotion uses cytoplasmic streaming and large blunt pseudopodia (lobopodia); ectoplasm is rich in actin microfilaments (F-actin) while endoplasm contains free actin subunits (G-actin); Amoeboid movement occurs by cyclic conversion of actin between G-actin and F-actin. At the leading edge, G-actin polymerizes into F-actin, forming a gel-like ectoplasm that pushes the membrane forward to form pseudopodia.
Endoplasm then streams forward into this extension, while actin filaments at the rear depolymerize, allowing the cell body to move forward.

what type of locomotion is fastest in unicellular eukaryotes

ciliary motion

what are the two kinds of flagellum; draw them

Tractellum – a flagellum that draws water toward and over the cell body; In sessile flagellates: Moves water across cell surface (i.e. prevents stagnation), Brings food particles towards the organism

Pulsellum – a flagellum that propels the cell in a cell body first direction; In free-living flagellates: Moves organism through water like a tadpole

what are filopodia

much slimmer than lobopodian, contain only ectoplasm and lack a hyaline cap

what are reticulopodia

elaborate, extremely thin filaments that branch and coalesce repeatedly in highly complex patterns

draw a diagram that displays the different types of nutrition among unicellular eukaryotes

Autotrophs or Heterotrophs

Heterotrophs can be either Phagotrophs or Osmotrophs

What is an autotroph

synthesize their own food (i.e. do not eat other organisms nor substances derived from them)

What are heterotrophs

obtain organic molecules synthesized by other organisms

what are osmotrophs

absorb soluble food through pinocytosis; also known as saprozoic

what are phagotrophs

ingest visible particles through phagocytosis (lobopodia extend around particle); also known as holozoic

explain phagocytosis

cell membrane binds to food particle and encloses around it to form a food vacuole

describe the interesting feeding mechanism of didinium

free-living ciliophoran that uses a non-ciliated cytopharynx to engulf prey

describe the interesting feeding mechanism of stentor (vorticella)

free-living ciliophoran that transforms into a horn-like structure; utilizes cilia to generate feeding current towards horn

describe the interesting feeding mechanism of suctorian

utilizes hollow tentacles with an opening on the tip to snag other protozoans and suck their cytoplasm

what are the types of excretion among unicellular eukaryotes

exocytosis, passive diffusion, cytoproct

what is exocytosis

elimination of undigested material within digestive vacuole occurs via fusion with cell surface (i.e. endocytosis in reverse)

what is passive diffusion

metabolic wastes readily diffuse across cell membrane; e.g. end products of nitrogen metabolism, like ammonia

what is a cytoproct

permanent excretory pore; waste accumulates in a vacuole adjacent to the cytoproct and is periodically discharged

what is osmoregulation

process of maintenance of salt and water balance across membranes within the body’s fluids

how does osmoregulation work in unicellular eukaryotes

freshwater is hypotonic relative to cytoplasm, so water is constantly diffusing into the cell; contractile vacuole prevents the cell from absorbing too much water and possibly lysing through excessive pressure; water does not get pumped directly into the vacuole, instead, H+ ions are pumped by ATPase (HCO3- also is moved in) → an osmotic gradient forms → water follows passively → carbonic anhydrase (an enzyme) replenishes the ions in the cytoplasm which reverse the gradient

why are contractile vacuoles uncommon in marine/parasitic unicellular eukaryotes, but common in freshwater

freshwater is more diluted than the internal environment of the eukaryotes, diffusive ion loss and water uptake by osmosis would result in dilution of the cytoplasm and eventual death

what are sponges

sessile multicellular animals with no organs but possess functionally distinct cell types

explain the arrangement of sponge body

cells lining interior surfaces and exterior surfaces, gelatin-like extracellular substance called mesohyl between layers

what are the different cell types of sponges

choanocytes, archeocytes, secretory cells, pinococytes, porocytes

what are choanocytes, sketch it

ovoid cells that line canal systems and chambers; exposed end is a collar shape that acts as a filtering device; the flagellar motion pulls water through the ‘filter’

what are archeocytes

amoeboid cells that receive and digest food particles from choanocytes; totipotent: give rise to all other cell types in the sponge

what are secretory cells

produce spicules through secretions

three subtypes:

sclerocytes - mineral spicules

spongocytes - spongin spicules

collenocytes - collagen spicules

what are pinacocytes

form protective lining (pinacoderm) that faces the external environment; also line some internal canals where choanocytes are not present

what are porocytes

form channels in pinacoderm through which water flows to the inside of the sponge (ostia)

draw a diagram of the general arrangement of cell types in porifera bodies

see image

what are the types of canal systems present among porifera

asconoids, syconoids, leuconoids

describe asconoids, draw it

flagellated spongocoels

describe syconoids, draw it

flagellated canals

describe leuconoids, draw it

flagellated chambers

how do porifera reproduce

both asexually and sexually

what are gemmules

form of asexual reproduction + survival structure since sponges are sessile and can’t escape poor environmental conditions; totipotent archaeocytes cluster together, phagocytose other sponge cells to store nutrients, form a capsule of spongin and microscleres, and the archaeocytes with nutrients are sealed and protected during harsh conditions; they will open when conditions improve

how do sponges reproduce asexually, draw a picture

fragmentation or budding

what are viviparous sponges

monoecious (one individual makes both sperm and eggs) sponges that form sperm from choanocytes (located in special flagellated chambers and released into the water via the osculum) and eggs from archaeocytes (remain inside the spong and are distributed throughout mesohyl); sperm enters through oscula and fertilizes eggs, zygote develops and forms a parenchymula larva that is released into the water

what are oviparous sponges

dioecious (one sponge makes eggs another makes sperm) sponges that release egg and sperm to the environment, usually in mass spawning events; fertilization occurs externally and embryonic development occurs in the water; eggs are surrounded by nurse cells which captures sperm and sinks to substrate

what are parenchymula

flagellated larvae of sponges

how do sponges reproduce sexually

Sponges reproduce sexually in two different ways:

1. Viviparous (internal fertilization + larval release)

2. Oviparous (external fertilization)

give a general overview of traits of cnidaria

polymorphic (2 body forms: polyp and medusae), 2 germ layers (ectoderm, endoderm), radial symmetry, gastrovascular cavity with single opening surrounded by tentacles, cnidocytes (contain cnidae)

draw a diagram of both a polyp and medusa morph

see image

what does diploblastic mean and what phylum has this trait

having a body derived from only two germ layers (endoderm and ectoderm, no mesoderm); cnidaria

which classes of cnidarians have a polyp body form and which do not, what about medusae

all have a polyp body form though it is reduced in scyphozoa and cubozoa; medusae present in hydrozoa, scyphozoa, cubozoa, absent from anthozoa and staurozoa

describe the different types of polyps in a sessile polymorphic colonial cnidarian and give an example

§  Gastrozooid polyps

·      Feeding polyps with mouth and tentacles for prey capture

§  Dactylzooid polyps

·      Naked polyps without mouth

·      Functions for defense of colony

§  Gonozooid polyps

·      Reproductive naked polyps without mouth

Produce male or female gametes/medusae – could be producing eggs and sperm but in most cases are producing female and male medusae respectively that can swim around freely and reproduce when they come together, forming a new colony

¨    Asexual reproduction basically – the polyps are genetically the same – budding occurring at the basal stolon

describe the morph types in free living polymorphic colonial forms of cnidaria and give an example of such a species

Gonozooids: Male and female; One colony will be either male or female, not both – they release gametes into the water for fertilization

Gastrozooids: With tentacle; Terminal mouth for feeding

Dactylzooids: With highly retractable tentacle

e.g. portugeuse man of war

gas-filled float is a single polyp called a pneumatophore

describe the traits of hydrozoan cnidaria and draw a diagram of their body form

¨    Velum = shelf-like area at the bottom of the bell

¨    Manubrium = bell clapper (uvula)

¨    Ring canal runs along all of the base of the circumference

¨    Nutrients in from mouth to gastrovascular cavity then flow down radial canal to ring canal and through tentacles