BIO lecture module 4 exam animals

What phylum is monoblastic?

Porifera

What phylum exhibits asymmetry?

Porifera

What clade develops mouth first?

Protosomes

What clade develops anus first?

Deuterosomes

What clades make up protosomes?

Lophotrochozoans and ecdysozoans

What phyla make up lophotrochozoans?

Mollusca, flatworms, and annelids

What phyla make up ecdysozoans?

Nematodes and Arthropods

What phyla make up protosomes?

Mollusca, flatworms, annelids, nematodes, arthropods

What phyla make up deuterosomes?

Echinodermata and Chordates

What phylum is diploblastic?

Cnidarians

What phylum exhibits radial symmetry?

Cnidarians

What clades are triploblastic?

Protosomes and deuterosomes

What clades exhibit bilateral symmetry?

Protosomes and Deuterosomes

What shared derived trait do mollusca and annelids have?

A coelom

What derived trait do flatworms have?

They are acoelomates

What derived trait do nematodes have?

A pseudocoelom

What phyla exhibit specialized segmentation?

Chordata and atrhopoda

What phylum exhibits repetetive segmentation?

Annelida

What phylum exhibits fused segmentation?

Arthropoda

What are the most notable appendages of Cnidarians?

Tentacles

What are the most notable appendages of molusks?

A muscular foot and sometimes tentacles

What are the most notable appendages of annelids?

Parapodia (sometimes), and setae

What are the most notable appendages of arthropods?

Their appendages are jointed

What are the most notable appendages of echinodermata?

Tube feet

What are the most notable appendages of chordates?

Limbs, fins, and wings

What kind of nervous system do Cnidarians have?

A nerve net

What kind of nervous system do flatworms have?

Ladder-like

What kind of nervous system do annelids and arthropods have?

A segmented nervous system

What kind of nervous system do echinodermata have?

A radial nervous system

What kind of nervous system do chordates have?

A centralized nervous system

What are choanocytes in sponges?

Flagellated cells that create a water current and capture food cells

What are archaeocytes in sponges?

Amoeba-like cells that help with digestion, transport, and repair

What cells make sponge skeletons?

spicules and/or spongin

Why do we care about sponges?

They are a foundation species and are a home and food source of many animals

Why do cnidarians have an “incomplete” digestive system?

They only have one opening to act as both the mouth and anus

What specialized cells do cnidarians have to catch prey?

nematocysts (they act as poison harpoons)

What are the two life stages of cnidarians and how do they differ?

Medusa (motile, sexual reproduction)

Polyp (sessile/ don’t move, asexual reproduction)

Why do we care about cnidarians?

They are a foundation species and food source

In protosomes, how does the blastopore (first developed opening) become a digestive track?

The blastopore develops into a mouth and then an anus

What two features/life stages unite lophotrochozoans?

Lophophore (feeding structure)

Trochophore (life stage)

Why are flatworms dorso-ventrally flattened?

They have no circulatory or respiratory systems

What is cephalization?

Where nervous tissue and sensory organs are concentrated at the front

Why do we care about flatworms

They are water quality indicators and are useful in biomedical research related to regenerative properties

What is meant by a “complete” digestive system?

They have both a mouth and an anus

What is metamerism?

Repetition of similar body segments

What is the difference between oligochaete and polychaete worms (morphologically)?

Oligochaetes: Few setae, no parapodia, simple morphology

Polychaetes: Many setae, have parapodia, well-developed head

What feeding strategies are exhibited by annelids?

Deposit feeding (detritivores), filter feeding, predation, scavenging

Why should we care about annelids?

They are critical decomposers and are soil and water quality indicators

What are the three major morphological features that most mollusks share?

A muscular foot, visceral mass, a mantle

How are the three main morphologies of mollusks adapted in gastropods?

The foot is a broad muscle used for crawling and adhesion

The visceral mass rotates during development and becomes asymmetrical

The mantle secretes a spiral shell, which is reduced or absent in slugs

How are the three main morphologies of mollusks adapted in bivalves?

The foot becomes a wedge/ anchor used for digging and attachment

The visceral mass is flattened, and houses gills for filter feeding

The mantle forms two shells which enclose the inner cavity

How are the three main morphologies of mollusks adapted in Cephalopods?

The foot becomes arms and tentacles and a funnel/ siphon is formed for propulsion

The visceral mass becomes a highly developed nervous system

The mantle drives jet propulsion

What are radula used for?

A tongue-like ribbon with tiny little teeth used for scraping food off of surfaces or grinding up food

What are siphons used for in bivalves and cephalopods?

Bivalves: To draw water in and out for filter feeding

Cephalopods: Used for jet propulsion

What are chromatophores and iridophores?

Chromatophores are pigment sacs that change color from muscle contractions

Iridophores contain layers of reflective plates that scatter and reflect light

Why do we care about mollusks

They are filter feeders that filter out pollutants and store, and they are a global food source

What process unites two very different groups of organisms?

The process of molting unites both nematodes and arthropods

Why is C. elegans a good model system in biology?

It is simple and well understood and shares many basic biological processes with more complex animals

What is eutely?

when an organism has a genetically determined amount of somatic cells as an adult

Why do we care about roundworms?

Some of them are human parasites

What percent of all species are arthropods?

more than 80%

Approximately how many insects are there per human?

About 160 million per human

What are the most abundant organisms in the ocean?

Copepods

How do jointed appendages lead to more diverse movements?

It allows for complex movements and more specialized segments

What are tagmata?

They are specialized body regions formed when multiple segments fuse together

What are the two specialized pairs of appendages in all chelicerates?

Chelicerae are used for feeding and biting

Pedipalps are used for sensing, food handling, and sometimes reproduction

What are biramous appendages?

A limb that is split into two branches from a single base segment

What is the main difference between centipedes and millipedes?

Centipedes have one pair of legs per segment

Millipedes have two pairs of legs per segment

How is diversity of insect mouthparts related to their overall diversity?

It allows different species to exploit different food sources

What are the different adaptations to the winged insects?

Full functional wings used for flight

Wings folding, wings can be folded over the body for protection when not in use

Wing hardening, the front most wings are modified into hard, protective covers

Wing reduction or loss is present in some insects

Wing coupling and synchronization, both wings are together as one unit

Why do we care about arthropods?

Many of them are pollinators , they are a global food source for many animals, and they help in pest control

In deuterosomes, how does the blastopore (the first developed opening) develop into a digestive track?

The anus forms first and then the mouth

What is the unique kind of symmetry found in echinodermata?

pentaradial symmetry (division into 5 parts), star-like

What is the difference in the surfaces of echinodermata compared to most other animal phyla?

Their skin is supported hardened skeletal calcium carbonate plates

What feeding strategies are exhibited by echinoderms?

Predation, scavenging, deposit feeding (detritivores), filter-feeding

Why do we care about echinoderms?

They are critical food web components that maintain and promote biodiversity

What are the four synapomorphies of chordates?

A dorsal hollow nerve cord

Pharyngeal gill slits

What ancestral traits are lost in some chordates?

Notochord is lost or replaced with a vertebral column

Tail may be reduced or absent

Pharyngeal slits may be modified

What ancestral trait is lost in some arthropods?

Wings and the ability of flight

What ancestral trait is lost in echinoderms?

Radial symmetry is replaced by pentaradial symmetry

What ancestral trait is lost by nematodes?

Segmentation is lost (no true segmentation)

What ancestral trait is lost in flatworms?

Coelom (they are acoelomates/ don’t have a coelom)

What ancestral trait is lost in porifera?

Tissues, they lack true body tissue

What is the process of incomplete metamorphosis?

Egg —> Nymph (immature form) —> Adult

What is the process of complete metamorphosis?

Egg —> Larva (feeding stage) —> Pupa (reorganization stage) —> Adult

Why are tunicates (urochordata) and lancelets (cephalocordates) chordates if they dont have spines?

Both tunicates and lancelets have the four synapomorphies of chordates at some point in development or in a simplified form

What is the relationship between the notochord and the vertebral column?

The notochord is mostly replaced by the vertebral column in vertebrates

What are the main synapomorphies of tunicates (urochordata)?

Larva: Pharyngeal gill slits, notochord, dorsal hollow nerve cord, post-anal tail

Adults: Non-living cellular exoskeleton (tunic) and pharyngeal gill slits)

What are the main synapomorphies of cephalochordata?

Adults

• Pharyngeal gill slits

• Notochord

• Dorsal hollow nerve cord

• Post-anal tail

What are similarities and major differences between hagfish and lamprey?

Similarities

• Jawless

• No true vertebral column in adults

• Eel-like

• Lack paired fins

Differences

• Vertebrae: Hagfish-Absent, Lamprey-Present

• Eyes: Hagfish-Reduced, Lamprey-Functional

• Larval stage: Hagfish-No, Lamprey-Yes (ammocoete)

What is an anadromous fish?

A fish who spends most of their life in salt water, but migrate to freshwater to reproduce

Usually born in freshwater

Migrate to ocean to mature

What is the skeleton of chondrichthyes (cartilageinous fishes) made of?

Cartilage

How does the presence of a jaw impact feeding habits for condrichthyes (cartilageinous fishes)?

Enables active prey capture

Allows mechanical processing of food

Expands dietary diversity

Improves feeding control

How do the lateral line and ampullae of Lorenzini impact cartilaginous fish feeding methods?

Lateral line system- detects vibrations and movements of prey

Ampullae- Detect electrical fields and signals

What is Actinopterygii (ray-finned fishes) skeleton made of?

Bone

What are swim bladders and why are they important phylogenetically?

Swim bladders are a sac with adjustable volume filled mostly with oxygen to allow ray-finned fishes more buoyancy control

It is important phylogenetically because it likely evolved from an ancestral gas-filled organ that could have also evolved into lungs

How does fin morphology in ray-finned fishes affect diversification of life histories?

Different fin shapes allow for different swimming abilities such as different feeding strategies, different predator avoidance strategies, and migration

Lobe-finned Fishes: What are similarities and major differences between coelacanths and lungfish?

Similarities

• Lobe-finned fishes

• Ancient lineages

• Have lungs or lung-like structures

• Have internal skeletons

Differences

• Breathing: Coelacanth- Gills and lung-like organ, Lungfish- Lungs

• Activity level- Coelacanth- Very slow, Lungfish- More active when water available

What is an ectotherm in amphibians?

Relies on exxternal heat sources to regulate its body temperature

How does the skin of amphibians make them vulnerable to environmental change?

Their skin is highly permeable making them susceptible to toxins and pollutants, low moisture, and climate change