Animal Diversity Flashcards
How are animals classified and who devised the system?
Classified according to the Hierarchial System devised by Linnaeus.
What is the layout for the classification system?
Phylum Class Order Family Genus Species
What is the taxonomy for a human?
Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: sapiens
What is specific to the phylum, chordata?
Animals have a ‘backbone’
What are the four main characteristics for an animal?
Multicellular
Heterotrophic
Internal digestion
Movement and nervous systems.
How many phyla are within the animal kingdom?
Between 32-39
How many know species are there of the phyla, Cycliophora and where are they found?
Three known species which are found on the mouth parts of lobsters.
What is the estimated common ancestor between all animals?
A colonial flagellate
What phyla are sponges classified under and how many species are known?
Porifera and 5,500 known species.
Describe cells in a sponge
Cells are embedded in spongin and are supported by spicules.
How do sponges gain oxygen and food?
Provided from water currents that are generated by collar cells.
How do collar cells generate water currents?
Beating flagellum creates the water current.
What is a collar cell made up of and what are they alternatively known as?
Made up of micro hairs which filter tiny food particles. Sometimes know as choanocytes.
Name the cells sponges are made up of
Pinacocytes, porocytes and amoebocytes.
What is the role of pinacocyte cells?
They are contractile and so act a bit like muscle. They are able to slightly change the shape of the sponge and so can control water currents and also produce collagen.
What is the role of porocyte cells?
Allow water to pass through the body walls
What is the role of amoebocyte cells?
They move around the body and carry out a number of tasks.
Some secrete spicules or spongin and others become reproductive cells.
Why are spicules important?
Important for species identification and provide skeletal support.
What do species classed under the phyla Porifera all have in common?
All aquatic animals, mostly marine found up to 5.5 miles down.
How much water can a large sponge filter in a day?
1500 litres
Why is embryonic analysis important?
Provides key differences between animal groups.
Describe the embryonic development of a sponge
Zygote (cleavage) eight cell stage (cleavage) Blastula (gastrulation) Gastrula.
What are the two layers of cells called that make up a diploblastic embryo?
Endoderm and ectoderm.
What do the endoderm and ectoderm develop into?
Ectoderm develops into outer skin and endoderm develops into the gut lining.
What is the third layer called in a triploblastic embryo found in other animal groups?
Mesoderm
What and how many species are classfied under the phyla, Cnidaria?
10,000 known species of sea anemone, jellyfish and coral.
What are the five main features of animals in the phyla Cnidaria?
Bodies contain tissues Diploblastic Hydrostatic skeleton Nematocysts (specialised stinging cells) Radial body symmetry
What are the two different body shapes of animals in Cnidaria?
Hydroid (sea anemone)
Medusoid (jellyfish)
What separates the two layers of cells found in a cnidarian body?
Mesogloea which is thick and jelly like in medusoid forms.
Hydra is a cnidarian species but why is it unusual?
Because it lives in freshwater.
What body form to corals take and what are they made up of?
Hydroid body form that is made up of a calcareous skeleton which is secreted by the coral.
What are siphonophorans?
A colonial hydrozoan that float using a gas bladder.
What are sea wasps and box jellyfish known as?
Cubozoans.
Describe how nematocysts work?
They entangle and penetrate prey and inject them with poison.
What and how many species are classed under the phyla, Platyhelminthes?
20,000 known species of parasite, some which are very important to humans.
What are the main features of animals classed under the phyla, Platyhelminthes?
Body is organised into organs.
Triploblastic
Cephalisation
Bilateral symmetry.
Name some species classed in platyhelminthes phyla
Freshwater and marine free living flatworms.
Large terrestrial flatworm.
What would a cross section of a flat worm show?
Cilia and complex musculature.
What is the name of the most important liver fluke and where is it commonly found?
Clonorchis which is commonly found where fish is eaten raw.
What do blood flukes like Schistosoma cause in humans?
Causes schistosomiasis in around 200 million people world wide. Causes pain, anemic and dysentary.
What is the name of a highly specialised parasitic flatworm that lives in the digestive tract of vertebrates. (4000 species)
Tapeworm
How has the mesoderm developed in platyhelminthes species like the flatworm?
The evolution of the mesoderm has allowed for the development of a fluid filled body cavity in which organs can be stored.
What is the name of the fluid filled cavity in a flatworm?
Coelom.
What is the fluid filled cavity called in a nematode?
Pseudocoelom
How many know species are classed under the phyla, Nematoda?
12,000
What are the main features of animals in the phyla, Nematoda?
Triploblastic
Fluid filled pseudocoel
Hydrostatic skeleton
Longitudinal muscles present
What would be seen in a cross section of a nematode worm?
Oviduct, uterus, ovary, muscle, intestine, pseudocoel, excretory duct, cuticle and nerve cord.
Describe the life cycle of a hook worm
Larvae enter body through skin or mouth and travel through the bloodstream to the lungs. Lung secretion containing larvae is coughed up and swallowed. Larvae pass into intestines where they mature into adults. Sharp hooked adult head clings to intestines. Females produce eggs and are left in the stool so eggs hatch into larvae in the soil.
What is special about C. elegans?
First species to have genome sequenced and only organism to have all 959 of its cells development understood.
What does body segmentation allow an animal to do?
Facilitates specialisation of different body regions and allows the animal to alter its body shape in complex ways due to segmented muscle clusters.
What is the original body plan for segmented animals?
Every organ is repeated in every segment.
What and how many known species are found in the phyla, Annelida?
16,500 species of true worms and leeches.
What are the main features of animals classed under the phyla Annelida?
Triploblastic
Fluid filled coelom which is divided by septa
Hydrostatic skeleton
Metameric segmentation (each segment has a complete set of organs)
Locomotion as segments can move independently.
Parapodia (fleshy appendages) with chitinous bristles called chaetae.
Tubular blood system with a contractile dorsal blood vessel.
Giant axons in nervous system.
How do animal in Annelida respire?
Through the skin, parapodia and gills.
What are the most familiar species of annelids? But where are most species found?
Earthworms are most common but most oligochaetes are freshwater or marine.
What is another diverse aquatic species of annelids?
Polychaete
Name an active predatory polychaete with a well developed head and parapodia
Nereids
What are Sabellids?
Tube dwelling polychaetes that filter particles from water.
What and how many species are classed under the phyla, Mollusca?
50,000 species of slugs, snails, squid, cuttlefish and octopus.