Diversity of animals Flashcards
What is a mollusk? Provide examples.
Mostly marine species with a variety of froms
EXAMPLES:
Chitons
* clams, oysters, mussels, scallops, geoducks
* snails, slugs, conchs, sea hares, sea butterflies
* Tooth shells
* octopuses, squids, cuttlefish, nautilus
(Cephalopods)
examples of annelids
include earthworms and leeches as marine forms
What are the key characteristics of mollusks
visceral mass, dorsal mantle and radula
what is visceral mass
contains most of the internal organs of the animal
what is dorsal mantle?
a flap of tissue over the visceral mass that creates a large cavity used for breathing and excretion
what is radula?
a scraping structure at the mouth
What is the characteristics of the mollusk circulatory system?
Most have an open circulatory system with a
heart circulating hemolymph in open spaces
around the organs
* Exception: octopuses and squid have a closed
circulatory system
* They have three hearts: two that move blood
through the gills and a third that pumps blood
through the rest of the body
what are the cephalopod special characteristics
- Females of some species care for eggs for extended period of time
- can move by fast jet propulsion due to mantle cavity contraction
- have complex eyes allowing stereoscopic vision
- have mollusk feets which developed into tentacles
- tentacles have suckers on them in octopus and squid
What are annelids? Provide examples.
are segmented worms found in marine, terrestial and freshwater habitats
- phylum includes earthworms, polychaete worms and leeches
- bilaterally symmetrical and have a worm - like appearance
EXAMPLES:Earthworm
* Leech
* Branchiobdellida, which live inside freshwater
crayfish and feed on algae
what is metamerism?
segmented body plan with repetition of internal and external features in each body segment
What are characteristics of annelid physiology?
- complete digestive system with specialized organs: mouth, muscular, pharynx, esophagus and crop
- well developed nervous system with two ventral nerve cords and a nerve ring around the pharynx
What is pharynx
passage leading from “mouth” to gut
what are echinoderms? Provide examples.
- Includes sea stars and sand dollars
- exclusively marine
- may have pigment cells, giving them vivid colours
- may have cells filled with toxins ( warning to predators that they are poisonous and can’t be eaten)
- can regenerate themselves
EXAMPLES:
*sea stars (aka
starfish)
* brittle stars
* sea urchins and sand
dollars
* sea lilies or feather
stars
* sea cucumbers
What are characteristics of echinoderm water vascular system?
- unique system for gas exchange, nutrient, circulation and locomotion which allows them to circulate oxygen
- a central ring canal and radial canals extending along each arm
- water circulates allowing for gas, nutrient and waste exchange
-provide for different cells for gas/nutrients exchange
What does the echinoderm tube feet do?
” Tube feet” may be expanded or contracted using the hydrostatic pressure in the system
- have slow movement, but a great deal of power
- tube feet can latch on to opposite halves of a clam, and slowly pull the shells apart exposing the flesh within
What are the four key features that appear at some stage of their development
- notochord, dorsal hollow nerve cord, pharyngeal slits, post and tail
what is the definition of notochord?
flexible, rod shaped structure found in the embyronic stage of all chordates and in the adult stage of some chordates ( located between digestive tube and the nerve cord)
- provides skeletal support through the length of the body
What does the chordate dorsal hollow nerve cord do?
Derived from ectoderm beneath the surface of the skin that rolls into a hollow tube during development
what does the chordate pharygeal slits do
openings in the pharynx just behind the mouth that extend to the outside environment
- invertebrate chordates use the pharygeal slits to filter food from the water that enters the mouth
- in jawed fish it become a jaw support
- in fishes, is modified into gill support
- in amphibians, reptiles, birds and mammals slits are modified into components of the ear and tonsils
What does the chordate post- anal tail do?
is a posterior elongation of the body extending beyond the anus
- tail contains skeletal elements and muscles
- helps with locomotion in aquatic species
what are invertebrate chordates?
chordates without backbones
tunicates and lancelets
* Lancelets
* Very small suspension
feeders
* usually found buried in
sand at the bottom of
warm temperate and
tropical sea
what are tunicates?
are sessile suspension feeders living in shallow ocean waters
what are vertebrates?
chordates with backbones
what are hagfishes?
eel-like scavengers
- have skull but no vertrebral column
- considered basal vertebrate
-living hagfish very similar to fossil from millions of years ago
What are lampreys?
- have a brain case and incomplete vertebrate who lack bones
- some of the species are parasitic and feed on body fluids of fish; most are free-living and live primarily in coasta and fresh waters in temperate regions
What is a jaw?
A hinged structure attached to the cranium that allows an animal to grasp and tear its food. It allows fish to exploit food resources that were unavailable to jawless fishes
what is the definition of cartilaginous fish?
sharks, rays, skates, sawfishes, ghost sharks
- they have paired fins and a skeleton made of cartilage, live in marine habitats
- most sharks are carnivores who feed on live prey, either by swallowing or using their jaws/teeths to tear it in to pieces
what is the definition of bony fish?
tuna, bass, trout, salmon, lungfishes, coelacanth
what are characteristics of rays and skates?
- found in marine environments, lives on ocean floors and have cartilaganeous skeleton like sharks
what are characteristics of sharks?
- have well developed sense organs that aid them in locating prey
- can detect movement and vibration in surrounding water using lateral line
- has electroreception
- are able to detect electromagnetic fields that are produced by all living things including prey
What are characteristics of bony fish?
- has a bony skeleton
- a very large number of species, making it the largest living vertebrate class
- have a lateral line like sharks
- have taste cells in head/trunk, allowing them to detect small concentrations in water
what is the definition of swim bladder?
a gas-filled organ that helps to control the buoyancy of the fish
What are amphibians? Provide examples.
Vertebrates with four limbs, have moist permeable skin which allows O2/ Co2 exchange with the environment and some have a sticky tongue which is used to capture prey
EXAMPLES:
“tailed-ones”: salamanders and newts
* “tail-less ones”: frogs and toads
* “legless ones”: caecilians
What are characteristics of tailed- ones salamander?
some are aquatic, and some terrestial. They have four limbs and a tail. Lay eggs. Some are lungless; respiration occurs through the skin or external gills
Tail - less ones: Frogs
- very diverse group of amphibians, are four limbs and no tail as adults. they lay eggs
Frogs
- body plan specialized for land movement
- can jump many times their body length
- have modifications that allow them to avoid predators
- camouflaged skin
- poisonous defensive chemicals secreted from skin glands
Legless ones: caecillians
They lack external limbs and resemble giant earthworms, inhabit soil in the tropics and have a soil burrowing lifestyle and are nearly blind. Most give birth to young offsprings and not eggs
reptiles,birds and mammals
- are all amniotes
- are different from amphibians due to their eggs having shells or an embryo protected by amniotic membranes
- membranes of the amniotic egg allowed for gas exchange and waste sequestering within the eggshell
What are amniote characteristics
Bird eggs, reptile eggs and mammals
what are bird eggs?
have shells composed of calcium carbonate that are hard and brittle, with pores for gas and water exchange
what are reptile eggs?
shells that are leathery and pliable
what are mammals
most mammals do not lay eggs but have amniotic membranes in internal gestation
what are the characteristics of reptiles?
- 4 limbs
- lay shelled eggs on land
- have scaly skin to prevent dehydration
- breathes through lungs
- conserve body water by excreting nitrogen as uric acid paste
What is ecotherms?
main source of body heat comes from environment
crocodilia
live throughout tropics, found in freshwater habitats, spend most of their time in water , some can move on land due to semi erect posture
lizards
have four limbs, eyelids and external ears
snakes
do not have four limbs, eyelids and external ears
- are found on every continent but antarctica
- all are carnivorous and eat small animals
turtles
have a bony or cartilaginous shell
- very old - evolved before lizards, crocodiles and snakes
- Turtles live in the seas
- tortoise live on land
- terrapins live in fresh water
birds
have several feather types specialized for different functions which are used for flight and temperature regulation
what is the definition of endothermic?
generate their own body heath through metabolic processes
what is the definition of feather
modified reptillian scales
what is pneumatic bones
hollow bones with air inside
- are fused vertebral skeleton and braincase to increase structural support
Mammals
vertebrates that have hair and mammary glands used to provide nutrition for their young
- hair provides insulation, protective, colourization and sensory information
what is the definition of sebaceous glands?
secrete sebum onto the hair and skin for water resistance/lubrications
what is the difference between sudoriferous glands and mammary glands?
SUDORIFEROUS GLANDS: produce sweat/scent used in thermoregulation and communication
MAMMORY GLANDS: produce milk that is used to feed newborns, some male lack these
What is Heterodent teeth?
teeth with different shapes and sizes that allow them to eat different foods
what is the definition of incisors and canines?
cutting and tearing
what is the definition premolars and molars
crushing and grinding
what are the three types of mammals?
monotremes, marsupials and placental mammals
what are monotremes?
platypus, spiny anteaters
what are marsupials?
kangaroo , koala and bandicot
What are placental mammals?
rats, bears, bats, whales, dogs, primates, humans, many more
what are characteristics monotremes?
- live in australia and New guinea
- the only mammals that lay eggs
- lay leathery eggs, like reptiles, rather than giving birth to live young
- eggs kept within the mother’s reproductive tract until they are ready to hatch
- when young hatch, female secretes milk
- like other mammals are endothermic but have lower body temperature
- like reptiles, have one posterior opening for urinary/fecal/reproductive products,rather than 3 openings like placental mammals
What are characteristics of marsupials?
most species have a pouch where offspring reside after birth
- in pouch, young receive milk and continue to develop
- young are born much less developed than in placental mammals
- are found mostly in Australia and nearby islands
What are characteristics of placental mammals
- the most widespread of the mammals, spread throughout the world
- all species have a complex placenta, that connects a fetus to the mother, allowing for gas, fluid, waste and nutrient exchange
What are the two main groups in order primates?
strepsirhines and haplorhines
What is the difference between strepsirhines and haplorines
STREPSIRHINES: nocturnal, smaller size, smaller brains, more likely to be solitary, greater reliance on sense of smell
HAPLORINES: dilurnal, larger size, larger brains, more likely to be group - living, greater reliance on vision
What is the definition of taxonomy?
biological field that specializes in delineating the rules of classification, including naming and categorizing organisms
