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 Only eat plants Ex: koalas, deer, rabbits etc. Only eat meat. Ex: Lions, tiger, wolves Eat both meat and plants. Ex: Bears, humans Herbivores- Carnivores- Omnivores- 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 Why? Genetic Diversity Better able to evolve and adapt How would homeostasis affect reproduction?
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 simplest and oldest animals sessile throughout adult life Quite different from other animals Like Animals Unlike Animals Multicellular No distinct mouth or gut Heterotrophic No tissues No cell wall Some specialized cells No organ system Asymmetrical
Osculum- large hole at the top where the water exits Choanocyte= uses flagella to move the water 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 Used for: Defense Capture Prey Video Nematocyst- poisoned filled stinging structure Contains a coiled dart explode Thousands at once Can paralyze or kill 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 Video 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
Platyhelminthes
There are over 18,000 species of flatworms. They are divided into three classes: Flukes Planaria Tapeworms 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 only one opening. Food enters and wastes leave through the same 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 anterior end which serve as a primitive brain. Eyespots are sensitive to light. Has a ladder like arrangement of nerves from the brain to the body. Can respond to simple stimuli such as: heat, cold, touch, light, chemicals.
1 = Brain or ganglia 2 = Eyespot 3 = Pharynx 4 = Ventral Nerve 5 = 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.
Special Feature 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.
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
Video
Tapeworms 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.
Video Part 2
The Phylum Nematoda Members 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
Look! An advancement! 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.
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? A female can produce 200,000 eggs per day. They can completely block the intestine of the host.
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
Annelids get their name through their visible segmented body. Oligochaets Leeche s Polychaete s
Annelids have complex organ systems because of the segmented body. Food enters the pharynx (two sharp jaws) Food enters pharynx, into esophagus, moves through crop and can be stored in the intestine 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 Response Two kinds of waste Digestive waste= through anus Cellular waste containing nitrogen= nephrida Nervous System Brain- Spinal Cord
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 muscles of the body wall are separated The advantages of having a true from those of the gut. The body wall muscles can coelom contract are: 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 Mollusca Tissues- Yes Germ Layers- 3 Cephalization- Some Symmetry- Bilateral True Coelom
Members of this phylum include: Clams Oysters Mussels Scallops Snails Slugs Nudibranchs Octopus Squid Chambered nautilus
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
Radula The radula is the main feeding adaptation in many mollusks. It is a flexible, tonguelike structure with abrasive teeth. It is used to cut food or to scrape food from a surface.
Respiration 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.
Members of this class include: Cuttlefish Octopus Squid Chambered Nautilus All of these are specialized for a freeswimming, predatory lifestyle. The Class Cephalopoda
#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 System Cephalopods 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