DIVERSITY OF ANIMALS INVERTEBRATES Flashcards
What are the members of animalia?
- sponges and cnidarians
- flatworms, nematodes, and arthropods
- mollusks and annelids
- echinoderms and chordates
- vertebrates
What are the features of the animal kingdoms?
- All animals are eukaryotic
- most are motile
- animals require a source of food to grow and develop
- all animals are heterotrophic
- reproduce sexually
-offspring pass through a series of developmental stages that establish a determined body plan (refers to the shape of an animal)
What are tissues?
A collection of similar cells that had a common embryonic origin
what are the four main type of animal tissues?
nervous, muscle, connective and epithelial
what does the nervous tissue do?
contains nerve cells, which transmit nerve impulses
what does the muscle tissue do?
contracts to cause all types of body movements
what does the connective tissue do?
provide many functions, including transport and structural support
What does the epithelial tissue do?
covers the internal and external surfaces of organs inside the animal body and the external surface of the body of the organism
What happens during sexual animal reproduction?
During sexual reproduction, the male and female
gametes of a species combine in the process of
fertilization.
* Fertilization and fusion of the gamete nuclei
produce a zygote.
* Fertilization may be internal (e.g. land animals)
or external (e.g. aquatic species)
After fertilization, a developmental sequence
ensues as cells divide and differentiate.
* events in development are shared in groups of
related animal species
* During development, animal cells specialize
and form tissues, determining their future
morphology and physiology
What are the forms of asexual reproduction?
- budding/fragmentation and parthenogenesis
What is budding/fragmentation?
part of a parent can separate and grow into a new individual
what is parthenogenesis?
unfertilized eggs develop into new offspring
what are the three animal body symmetry?
- assymetrical, radial or bilateral
what is asymmetrical symmetry?
animals have no pattern in body plan
What is radial symmetry?
animals have a longitudinal orientation, mirrored halves when cut up and down
what is bilateral symmetry?
a vertical plane cut from front to back separates the animal into roughly mirror- image right and left sides
What are the two germ layers of embryonic develpment?
diploblast and triphoblast
what is the difference between diploblast and triphoblast?
DIPLOBLAST: animals that develop two embryonic germ layers ( have radial symmetry)
TRIPHOBLAST: animals that develop 3 embryonic germ layers (have bilateral symmetry)
what are the characteristics of sponges?
- have specialized cells for particular functions
- lack true tissues in which specialized cells are organized into functional groups
- similar to colonial, flagellated protists
- similar to the ancestor of animals
- live in intimate contact with water
- is dedicated to moving water through the body which allows the sponge to filter out food and absorb dissolved oxygen and eliminate waste
how does the sponge body form?
water enters the large cavity from numerous pores in the body wall
what is intracellular digestion?
food particles that are trapped in mucus produced by inner layer of sponge body cells are ingested by phagocytosis
- sponge body cells take up nutrients repackaged in food vacuoles and deliver them to other cells withing the sponge
What is the difference between fragmentation and budding?
FRAGMENTATION: a piece of the sponge breaks off and develops into a new individual
BUDDING: an outgrowth from the that eventually detatches
what are the characteristics of sponge reproduction?
- sponges are monoecious(or hemphrodict): one individual can produce both eggs and sperm
- early larval development occurs within the sponge, and free swimming larvae are released from the body cavity
True or false? are cnidarials radial symmetric?
true
provide examples of cnidarians
jellyfish
what are the characteristics of cnidarian stinging cells?
- have specialized stinging cells located around the mouth and tentacles which can immobilize prey with toxin
- have hairlike projection that are sensitive to touch, when touched, the cells fire the toxin- containing coiled threads that can stun the predator or prey
what are medusae?
Medusae are motile with the mouth and tentacles hanging from the bell-shaped body
What are the characteristics of cnidarian physiology?
- two tissue layers include outer layer and inner layer lining the digestive cavity
- there are differentiated cell types in each tissue layer, like nerve cells, enzyme-secreting cells, and nutrient- absorbing cells
- nervous system is primitive, with nerve cells scattered across the body in a network
- nerve cells carry signals from sensory cells and to contractile cells
- have extracellular digestion, with digestion completed by intracellular digestive processes
what are the characteristics of cnidarian digestion?
Food is taken into the gastrovascular cavity,
enzymes are secreted, and the cells lining the
cavity absorb the nutrients
* gastrovascular cavity has only one opening that
serves as both a mouth and an anus (incomplete
digestive system)
* Gas exchange, circulation, and excretion occur by
diffusion between cells and the water
What are flatworms?
- are acoelomate organisms that include free -living and parasitic forms
what is acoelomate?
bodies contain no cavities or spaces between the outer surface and the inner digestive tract
What are characteristics of flatworms
- have three embryonic germ layers
- have an incomplete digestive system with opening for both food intake and waste output
- nervous system with a pair of nerve cords running the length of the body a large concentration of nerve cells at the anterior end of the worm
What is extracellular digestion?
enzymes secreted by cells lining the tract, and digested materials taken into the same cells by phagocytosis
What do flatworms include?
- free living marine or freshwater species
- species that are parasites of fish exteriors
- species that are parasites in the interiors of mollusks and other groups including humans and spend part of life cycle in mollusks
what are the characteristics of nematode
- nematodes, or
roundworms, possess a
pseudocoelom and
consist of both freeliving and parasitic
forms - Present in all habitats
and extremely
common, although
usually not visible - Most nematodes look like slender
tubes, tapered at each end - Nematodes have a complete digestive
system with a distinct mouth and
anus - nematode body is encased in a
cuticle, a flexible but tough
exoskeleton, or external skeleton
Cuticle made of chitin - exoskeleton provides
protection, but also
restricts growth - Exoskeleton must be
continually shed and
replaced as the animal
increases in size
excretory system is not
specialized and wastes are
removed by diffusion - Most nematodes have nerve
cords that run along the length
of the body and fuse in a ring
around the head and tail - Muscles under the epidermis
permit only side-to-side, wavelike undulation of the body - Nematodes have a diversity of
sexual reproductive strategies
depending on the species - Can be monoecious (one sex),
dioecious (separate sexes), or
may reproduce asexually by
parthenogenesis
What are the characteristics of arthropods?
- Arthropods are one of the most successful
taxonomic groups on the planet - Have a large central cavity, a hard exoskeleton
and jointed appendages - hard chitin exoskeleton covering their bodies
must be periodically shed and replaced for
them to increase in size
arthropods have a segmented body with
fusion of certain sets of segments to give rise
to functional segments - The open circulatory system: blood bathes the
internal organs rather than circulating in vessels - has a two-chambered heart
arthropod respiration
Book lungs: internal stacks of alternating air
pockets and tissue shaped like the pages of a
book
Book gills: external structures similar to book
lungs with stacks of leaf-like structures that
exchange gases with the surrounding water
