animals - the hole in the wall -...
TRANSCRIPT
Animals
What is an animal?
Heterotrophs
Multicellular
Eukaryotic Cells
No Cell Walls
Bodies contain tissues :
Epithelial
Muscular
Connective
Nervous
Epithelial
Cover body surfaces: skin, lining of lungs etc.
Muscular
Allows cells to contract for movement
Connective
Supports the animal and connects Ex: bone and blood
Nervous
Nerve Cells that carry information
Ex: Brain, Spinal cord, nerve endings
95% of animals = Invertebrates
Dust
mites
Giant
Squid
Invertebrate
Animal that does not have a
vertebral column, or backbone.
Vertebrate
Animal that has a vertebral
column, or backbone. • Only 5% of animals
What do animals need to survive ?
All animals want to keep at a state of homeostasis.
All based on FEEDBACK
INHIBITION
Includes:
Feeding
Respiration
Circulation
Excretion
Response
Movement
Reproduction
Let’s Think Why does the metaphor of Goldilocks and the three bears
work when explaining homeostasis and what animals need to
survive?
Feeding
Herbivores-
Only eat plants
Ex: koalas, deer,
rabbits etc.
Carnivores-
Only eat meat.
Ex: Lions, tiger,
wolves
Omnivores-
Eat both meat and
plants.
Ex: Bears, humans
Detrivores-
Decaying or dead matter
Ex: worms, vultures
Filter Feeders-
Aquatic animals
that strain floating
organisms from water Ex: whale
shark, sponges
Respiration All animals take in oxygen and give
out carbon dioxide
Sometimes done through diffusion
How would homeostasis affect
respiration?
Circulation Small animals= Diffusion for
nutrients
Large animals have a specialized
systems
How would homeostasis affect
circulation ?
Excretion Ammonia= waste product of cells
Build up in your body would be
toxic
Ex: Kidney Failure
How would homeostasis affect
excretion ?
Response Responding to the environment
Information Nerve cells
Ex: light, sounds, external stimuli
How would homeostasis affect
response?
Movement All animals are mobile
How would homeostasis
affect movement?
Reproduction Most reproduce sexually through
haploid gametes
How would homeostasis
affect reproduction?
Why ?
Genetic Diversity
Better able to evolve and
adapt
Simple Animals
Trends in Animal Evolution All animals who reproduce sexually
The fertilized cell goes through divisions until it becomes a __________BLASTULA
Blastula= hollow ball of cells
Will eventually fold in on itself and
create a blastopore
Germ Layers
Ectoderm= forms the
outside of the body
Ex: Skin and nervous
system
Hair, feathers, scales, nails
Mesoderm= Forms the
circulatory, reproductive,
urinary, and muscular
systems
Endoderm= forms the lining
of the gut and the digestive
track
THINK- How many germ layers
would a cat have?
Zygote formation
Body Symmetry
Radial- simple animals like sea anemone Structures repeat around the center like a bicycle wheel
Bilateral- an imaginary line can divide the animal into two equal parts Anterior – front end
Posterior- back end
Dorsal – upper side
Ventral- lower side
Cephalization Head and brain
Respond better to their environment
Explorative Activity Based on what we know regarding the different animal
phylum, use your observation skills and the jarred specimens
to make inferences to fill in your foldable.
Use pencil
Sponges Phylum Porifera
Like Animals
Multicellular
Heterotrophic
No cell wall
Some specialized cells
Unlike Animals
No distinct mouth or gut
No tissues
No organ system
Asymmetrical
simplest and oldest animals
sessile throughout adult life
Quite different from other animals
Choanocyte= uses
flagella to move the
water
Osculum- large hole at the top
where the water exits
Spicules
make the
‘skeleton’
Either
calcium
carbonate
or silica
Feeding
• Filter feeders
• Food is trapped and engulfed by choanocytes
Respiration, Circulation and Excretion
• Dependent water current
• Oxygen diffuses in, wastes diffuse out and away
Response
• No nervous system/ loose neural network
• Protection through toxins
Reproduction
• Sexually or asexually
• Eggs are fertilized inside the sponges body.
• Sperm are released from one sponge/ carried to an egg through water
• OR Asexually through budding of gemmules
Cnidarians
What are Cnidarians ?
Soft-bodied
Carnivorous
Stinging tentacles
Includes
Cnidocytes
Stinger Cells
Run along
tentacles
Nematocyst- poisoned
filled stinging structure
Contains a coiled dart
_____________explode
at once
Can paralyze or kill prey
Thousands
Video
Used for:
Defense
Capture Prey
Body Plan Radially Symmetry
Life cycle = polyp and medusa stages
Mouth points upwards
Sessile
Cylinder body w/ tentacles
Mouth points downwards
Motile
Bell Shaped
Digestion
Feeding
• Carnivores
• Paralyzes prey, pulls it into their gastrovascular cavity
Respiration, Circulation and Excretion
• Nutrients diffused through the body after digestion
• Waste is also diffused through their body walls
Response
• Special sensory cells
• Nerve net- lose network of nerve cells
• Also can sense gravity (statocysts)
• Can detect light (ocelli)
Movement
• Hydrostatic skeleton- anemone’s (layer of circulatory muscles and longitudinal muscles)
• Jet Propulsions- medusa’s (opening and closing of an umbrella)
Reproduction
• Asexually through budding
• Sexually though external fertilization= takes place outside the body
• Eggs and sperm are released into the water
Jellyfish- Scyphozoa
‘Cup animals’
The polyp exists in larval stage
Largest Jellyfish was 4 meters long in diameter and tentacles over 30
meters long
Reproduces sexually
Hydras and their relatives
Exists in colonies
Polyps are specialized to perform functions
IE- Portuguese man of war
1 polyp is the balloon like float
Other polyps produce tentacles (165 feet),
digestion, reproduction
Can kill humans (usually due to reactions)
Sea anemones and Corals- Anthozoa
Only polyp stage
Colonial
Coral grow slowly through budding
Can exist for hundreds of years
Reproduce sexually
Video
Platyhelminthes
Planaria
Flukes
Tapeworms
There are over 18,000 species of flatworms.
They are divided into three classes:
Tissues- Yes Germ Layers- 3 Cephalization- Yes
Symmetry- Bilateral
Flatworms can be:
Free Living: They live on
their own and are not
parasites.
Carnivores or Herbivores
Endoparasites:
They live inside a host.
Ectoparasites:They live on the outside of their
host.
The digestive system has onlyone opening. Food entersand wastes leave through thesame opening.
1 = eyespot
2 = pharynx
A = Anterior
B = Dorsal
C = Posterior
D = Ventral
Excretion in Planaria
Planaria must constantly rid themselves of excess water.A series of excretory tubes runs the length of the body.Each tube is connected to several flame cells. The flame cell collects excess water and excretes it through pores in the body surface.
They will not have:
Respiratory system
Circulatory System
How can flatworms
survive without
these two very
important
systems?
All cells are in close proximity to the external environment. O2 and CO2 are exchanged directly with the environment by diffusion.
Nervous System of the Planaria
There are two ganglia at the anteriorend which serve as a primitive brain.
Eyespots are sensitive to light.
Can respond to simple stimuli such as: heat,
cold, touch, light, chemicals.
Has a ladder like arrangement of nerves from the
brain to the body.
1 = Brain or ganglia 2 = Eyespot3 = Pharynx 4 = Ventral Nerve5 = Intestine 6 = Mouth
Reproduction in Planaria
Asexual Reproduction
Binary Fission:
The organism splits in
two, then grows back the
missing parts to form two
complete planaria
Regeneration:
The ability to grow back
lost or missing body
parts.
Video
Reproduction in Planaria
Sexual Reproduction
Planaria are
hermaphroditic:
They have both male and
female reproductive
structures.
They simultaneously
fertilize each other
Eggs are laid
in protective
capsules that
stick to rocks.
They hatch in 2
to 3 weeks.
Flatworms are ACOELOMATES
The three germ layers are packed very closely together to form a solid body.
There is no coelom (hollow, body cavity) between the endoderm and mesoderm.
Special
Feature
Flatworm Diseases
All disease causing flatworms are called FLUKES or
Tapeworms
May be endoparasites
May be ectoparasites
Flukes have two hosts.The Primary host is a mammal such as a sheep or human. A primary host is an
animal from which an adult parasite derives
its nourishment.
An intermediate host is an animal from
which a larval parasite derives its
nourishment.
ex: snail
Tapeworms may live in the intestines of almost all
vertebrates.
Tapeworms may enter the host when the host eats raw or
undercooked meat containing the eggs or larva of the tapeworm.
Symptoms include:
Digestive problems, weight loss, lack of energy and anemia.
Tapeworms
Video
Part 2
The Phylum NematodaMembers of this phylum are referred to as roundworms.
They have long, thin bodies that are
tapered at both ends.
Tissues- Yes, Germ Layers- 3
Cephalized- Yes Symmetry- Bilateral
Examples of
Roundworms Include:
Ascaris Hookworms
Trichinella Pinworms
Roundworms have a “tube within a tube” digestive system:
The digestive system has two
openings: a mouth and an
anus.
Food enters the mouth and
wastes leave the body through
the anus.
Look! An
advancement !
Feeding
• Decomposers
• Parasites
• 2 opening digestive system
Respiration, Circulation and Excretion
Diffusion for Oxygen/ Carbon Dioxide
Specialized cells to secrete waste (varies depending on species
No Circulatory system
Response
Can respond to environment through ganglia
Movement
Tapered at both ends so it can burrow into the tissues of its host
Has thick cuticule which prevents it from getting digested by host
Reproduction
Sexually
Diseases: Ascaris
Where is this worm commonly
found?
Ascaris lives in the intestines of pigs,
horses, dogs, humans, etc.
What happens if Ascaris becomes too
numerous in the host?
They can
completely
block the
intestine of
the host.
A female can produce 200,000 eggs per day.
Hookworms
The hookworm’s mouth has cutting hooks that clamp to the intestinal wall of the host.
Hookworm’s feed on the blood of the host.
The larva live in the soil. They enter a host by boring through the bottom of the feet.
Ways to control parasitic worms:
Good meat inspection.
Cook all meats thoroughly.
Wear shoes in areas occupied by host animals, such as barns, pastures, etc.
Wear protective clothing when wading in waters that may be infested with parasites.
Evidence of Parasitic Worms in
Humans
Save the Guinea Worm!?
The guinea
worm gets
passed to
humans
through the
drinking of
contaminated
water.
Instead of
passing the
larvae
through
feces, it exits
the body
through the
extremities.
Removal
Guinea Worm =
Dracunuliasis
Burning sensation
when the worm wants
to come out
Infected
person will
put their foot
it water to
cool
If the worm is broken before extracted, the area becomes swollen and
infected. The patient is under extreme pain.
Result? Must remove slowly. It can take up to a week to fully remove a 1
meter long worm!
The extinction of the Guinea Worm
YAY
?
What can be the
possible cause? (FYI:
Cannot be killed
through medicine or
pesticides)
Should this be a
species we ‘save’?Video
The Phylum Annelida Body divided by septs= internal walls between segments
Each segment can be unique with multiple eyes, antennae and other sense organs.
Tissues- Yes Germ Layers- 3
Cephalization- Yes Symmetry- Bilateral
Oligochaets
Leeches
Polychaetes
Annelids get their name through their
visible segmented body.
Annelids have complex organ systems because of the segmented body.
Food enters pharynx, into
esophagus, moves through
crop and can be stored in the
intestine
Food enters the pharynx (two
sharp jaws)
Range from filter feeders to
predators.
Circulation
Closed Circulatory System
Earthworm= two major blood
vessels
Run head to tail
Supports internal organs
Respiration
Aquatic- breathe through gills
Land- breath oxygen and give
off carbon dioxide through skin
Excretion
Two kinds of waste
Digestive waste= through anus
Cellular waste containing
nitrogen= nephrida
Nervous System
Brain- Spinal Cord
Response
They have a true coelom.
Lined with tissue derived from the
mesoderm.
Annelids are “coelomates”.
Animals that are coelomates have a true
coelom.
A coelom is a hollow, fluid filled body cavity that is completely lined with mesoderm
tissue.
All organ systems are suspended within this coelom.
The advantages of having a true
coelom are:
The muscles of the body wall are separated
from those of the gut. The body wall muscles
can contract without hindering the movement of
food through the gut.
A coelom provides a space where the
circulatory system can transport blood without
interference from the internal organs.
The gut and other internal organs are
suspended from the body wall and are
cushioned by the fluid within the coelom.
The Phylum MolluscaTissues- Yes Germ Layers- 3 Cephalization- Some
Symmetry- Bilateral True Coelom
Clams
Oysters
Mussels
Scallops
Snails
Slugs
Nudibranchs
Octopus
Squid
Chambered nautilus
Members of this phylum include:
What are the major features that distinguish the
three classes of mollusks from one another?
Gastropods: Have a single shell and a single large foot. They
have eyes on the ends of stalks on their heads.
Bivalves: Have a two part, hinged shell. They lack a head
and radula. They possess siphons for filter feeding.
Cephalopods: The foot has been divided into
tentacles. There is a large head with well developed
sense organs. They are the most intelligent of all the
invertebrates.
Feeding
Some are filter feeders like
clams
Others are predators/
carnivores like squid and
Octopus
RadulaThe radula is the main
feeding adaptation in
many mollusks.
It is a flexible, tongue-
like structure with
abrasive teeth.
It is used to cut food or to scrape food from a surface.
Gills are specialized for the
exchange of gases.
Gills have a large surface area in contact with a rich supply of blood vessels. Oxygen from the water diffuses into the blood vessels of the gills. Carbon dioxide in the blood diffuses across the surface of the gills into the external environment.
Aquatic mollusks possess gills. Land dwelling mollusks do
not have gills or lungs.
In land dwelling mollusks, oxygen diffuses across thin,
moist membranes to enter the body.
Respiration
Th
e C
lass C
ep
halo
po
da
Members of this class include:
Octopus
Squid
CuttlefishChambered Nautilus
All of these are specialized for a free-
swimming, predatory lifestyle.
#1 A circle of tentacles extends from the head
region. The tentacles have powerful suction cups
to grasp objects and capture prey.
#2 Cephalopods kill and eat their prey
with the help of a pair of jaws that looks
like the beak of a parrot.
#3 Many
cephalopods can
release a cloud
of ink into the
water to distract
predators.
#4 Cephalopods contains chromatophores .
These are pigment cells in the skin that
change color, allowing the cephalopod to
blend in with the surroundings.
Video
The Cephalopod Circulatory SystemCephalopods have a closed circulatory system.
The circulation of blood is enclosed inside a
system of blood vessels.
What is the advantage of a closed circulatory system?
A closed circulatory system transports fluid more quickly than an open circulatory system. If all nutrients, oxygen and waste can circulate faster, than activity level of the organism will increase.
The Cephalopod Nervous System
The cephalopod brain is the largest and most advanced brain of any of the invertebrates.
The octopus can learn to solve simple problems, can perform simple tasks, and can learn to differentiate between objects.
Cephalopods have well developed eyes that are capable of forming images of objects. Video
Reproduction of Cephalopods
Octopus reproduce sexually
Mothers will guard their young, depriving herself of food, until
they are born.
Video
What is the advantage of a true
coelom over a pseudocoelom?
A true coelom separates the muscles of the body wall from those of the internal organs. It provides a space for the circulatory system to transport blood without interference.
A closed circulatory system is advantageous over
an open system. Explain why an open circulatory
system is adequate for the gastropods.
Since gastropods move so slowly, they
consume very little energy. This makes
their need for nutrients and gas
exchange low. An open circulatory
system can adequately transport the
amount of oxygen and nutrients
needed for such a low metabolism.
What are the potential dangers of using a filter feeding
organism such as a clam or oyster as a food source?
If there is a contaminant in the environment in
which the clam or oyster lives, that contaminant
will be filtered from the water by the bivalve.
These toxins can accumulate in the tissues of
the organism.
If the water is polluted by sewage, the
clam or oyster may harbor many bacteria
that thrive in the sewage filled waters.
Arthropods
Echinoderms
Chordates
Use Guided Notes from
Textbook