7ch11 - bement.k12.il.us
Transcript of 7ch11 - bement.k12.il.us
7ch11
Animal DiversityKingdom Animalia
Animal Characteristics
1. animals are eukaryotes and are multicellular2. cells are specialized for different functions
(vision,digestion,reproduction)3. protein, collagen surrounds the cells and keeps their
shape4. obtain energy for life processes by eating other organisms5. animals digest their food6. most animals reproduce sexually7. capable of movement at some point in their lives
Animal Classification
1.5 million species of animals with more added every year
How are animals grouped and classified?
Vertebrates - an animal with a backbone
Examples: fish, humans, birds, snake
Invertebrate - an animal that does not have a backbone
Examples: worms, spiders, insects, snails
Symmetry
Another way to classify animals -
Symmetry - an organism’s body plan
Radial symmetry - can be divided into two parts that are nearly
mirror images of each other anywhere
through its central axis.
Radial symmetry
A radial animal has a top and a bottom but no head or tail
It can be divided along more than one plane and still have identical halves
Examples: jellyfish, sea stars, sea anemones
Bilateral Symmetry
Bilateral symmetry - can be divided into two parts that are
nearly mirror images of each other.
Examples: birds, mammals, reptiles, worms, insects
Asymmetry
Asymmetry - cannot be divided into any two parts that are
nearly mirror images of each other
Examples: sponge
Molecular Classification
DNA, RNA and proteins in the cells can be used for classification
The more similar the DNA, the more closely related.
Phyla
Animals are classified into 35 phyla, 9 phyla contain 95%
Animals in the same phylum have similar body structures and characteristics
Figure 5 page 379
Lesson 2 Invertebrate Phyla
no backbone
no internal support
smaller than vertebrates
often move slower than vertebrates
95% of all animal species discovered are invertebrates
Sponges - Phylum Porifera
simplest of the invertebrates
● all sponges are asymmetrical● have no tissues, organs, or organ systems● cells are specialized for capturing food, digestion,
reproduction, and providing support● all sponges live in water, most in ocean environments● larval stage swims
Cnidarians - jellyfish, sea anemones, hydras, corals
● no organs or organ systems● radial symmetry● single body opening, surrounded by tentacles● simple tissues- muscles, nerves, digestive tissues● specialized cells, nematocysts (stinging cells) for defense
and capturing food● all live in water, most in ocean environments
Flatworms - phylum Platyhelminthes
● Bilateral symmetry● Nerve, muscle, and digestive tissues, simple brain● Soft, flat bodies a few cells thick● Digestive system has one opening● Live in moist environments● Parasites or free-living
Roundworms - phylum Nematoda
● Called nematodes● Bilateral symmetry● Nerve, muscle, and digestive tissues and simple brain● Bodies round, with stiff outer covering called a cuticle● Digestive system has 2 openings● Live in moist environments● Parasites or free - living
Phylum Mollusca
Snails, slugs, clams, mussels, octopi, and squid
● Bilateral symmetry● Soft bodies, some with hard shells● Digestive system with 2 openings● Body cavity contains heart, stomach, other organs● Blood but no blood vessels● Nervous system includes eyes, simple brains● Must live in wet environments
Phylum Mollusca
3 Groups
Snails and slugs
Clams and mussels
Octopi and squid
https://www.youtube.com/watch?v=SesRrocIFtc
Phylum Annelida earthworms, leeches, marine worms● Bilateral symmetry● Soft bodies● Body segments covered with a thin cuticle● Digestive system has 2 openings● Blood and blood vessels● Simple brain● Live in water or moist environments
Phylum Arthropoda
Insects, spiders, shrimp, crabs, lobsters
More species belong to this phylum than all other animal phyla
More than 1 million identified species
Phylum Arthropoda - Arthropods
● bilateral symmetry● exoskeleton● jointed appendages● body parts are segmented and specialized for different
functions● live in almost every environment on Earth
Appendage is a structure, such as a leg, that extends from the central part of the body
Largest Order of Arthropods -- Insects
Insects: Three pairs of jointed legs
Three body segments
A pair of antennae
16 major groups of insects, most belong to one of five groups
Beetles form the largest group - 40% of all known insect species
Phylum Arthropoda -- Order Arachnids
Spiders, ticks, and scorpions
All arachnids have: four pairs of jointed legs
two body segments
no antennae or wings
Phylum Arthropoda - Crustaceans
Crabs, shrimp, lobsters
All crustaceans have : one or two pairs of antennae
jointed appendages that are specialized
for biting and crushing food
Phylum Echinodermata
Echinoderms - “spiny skin”
Sea stars, sea cucumbers, sea urchins, sand dollars
Echinoderms have some unique features that are not in
any of the other invertebrate phyla.
Echinoderms
Radial symmetry
Hard plates inside skin support the body
Small, muscular tubes enable them to move (tube feet)
Complete digestive system
Live only in oceans
Lesson 3 Phylum Chordata
A chordate is an animal that has
● a notochord, ● a nerve cord, ● a tail, ● And pharyngeal pouches at some point in its life.
A notochord is a flexible, rod-shaped structure that supports the body of a developing chordate.
The nerve cord develops into the central nervous system.
The pharyngeal pouches are between the mouth and the digestive system.
Most chordates are vertebrates, but the chordates also include two groups of invertebrates: tunicates and lancelets
Tunicates and lancelets are only a few centimeters long and live in salt water - figure 16 p. 393
In vertebrate chordates, the notochord develops into a backbone during the growth of an embryo
Phylum Chordata
Lancelets
Tunicates
Vertebrates
A chordate is an animal that has
● a notochord, ● a nerve cord, ● a tail, ● And pharyngeal pouches at some point in its life.
Characteristics of Vertebrates
Backbone - series of structures that surround and protect the nerve cord (spinal cord)
Bones that form a backbone are called vertebrae
The nerve cord connects all the nerves in the body to the brain
Characteristics of Vertebrates
Backbone
Organ systems - digestive system with 2 openings
circulatory system - moves blood
nervous system - includes brain
5 Major Groups of Vertebrates
Fish
Amphibians
Reptiles
Birds
Mammals
Fish
● Spend entire life in water● Gills for absorbing oxygen gas from water● Paired fins for swimming
Grouped into 3 classes
Jawless fish
Cartilaginous fish
Bony fish
Jawless Fish
Most of this early group are now extinct, but a few remain:
Lampreys and hagfish
No jaws
Some are parasites on other fish
Lampreys
Jawless Fish
Hagfish
Secrete slime when threatened
Look like eels but belong to their own
ancient family
Cartilaginous Fish
Skeletons are made of a tough fibrous tissue called cartilage
Sharks
Skates
Rays
Bony Fish
Largest class of vertebrates - 28,000 species
Examples:
Bony Fish
Skeleton of bone
Scales
Paired fins
One pair of gills
Jaws
Reptiles
Waterproof skin
Scales
3 chambered heart
Lungs
Fluid filled eggs with leathery shells
BirdsClass Aves
● Lightweight bones - mostly hollow inside to reduce weight● Skin covered with feathers and scales● Beaks - do not chew food but their digestive systems
include gizzards, organs for grinding food● Four chambered heart● Respiratory system has extra air sacs which allow more
oxygen to move through the lungs
● Most birds make nests for eggs - hard shells● Most have stiff outer feathers for flying● They feed and care for their young● Most have unique calls or songs
Mammals
All mammals have fur or hair
Chew food using teeth
Complex digestive and nervous system
Mammary glands that produce milk for young