Transcript Chapter 9 - cloudfront.net

Chapter 11 and 12
Structure and Function
of Invertebrates
and
Structure and Function
of Vertebrates

The cells of most animals are organized into higher levels of structure, including
tissues, organs, and organ systems. (Page 411) Tissues combine to form an organ.

Some major functions of animals are obtaining food and oxygen, keeping internal
conditions stable, moving, and reproducing. Page 412

Keeping Conditions Stable – All animals must maintain a stable environment within
their bodies to survive.

Animals are classified according to how they are related to other animals. These
relationships are determined by an animal’s body structure, the way the animals
develops, and its DNA. (Page 416)

Invertebrates – An animal that does not have a backbone. (page 416) Most animals
are invertebrates.

Vertebrate – An animal that has a backbone. (page 416)

Asexual reproduction: A reproductive process that involves only one parent and
produces offspring that are identical to the parent.

Sexual reproduction: A reproductive process that involves two parents that combine
their genetic material to produce a new organism, which differs from both parents.
What is an Animal?

Sponges are invertebrates that usually have no body symmetry and never
have tissue or organs. (Page 418) Sponges reproduce sexually and form a
larva, which is an immature form of an animal that looks very different from an
adult.

Sponges obtain food by straining food particles from the water that enters their
central cavity through pores. The water carries tiny organisms that are food for
the sponge. Collar cells on the inside of the central cavity trap the organisms.
Jelly-like cells farther inside the sponge digest the food particles. Water current
also takes away the sponge’s waste product.

Cnidarians use stinging cells to capture food and defend themselves.
Cnidarians have two different body plans. One form looks like a vase (polyp)
and the other form looks like an upside down bowl (medusa). Both body plans
have a radial symmetry, a central hollow cavity, and tentacles with stinging
cells. The vase-shaped body plan is called a polyp. The bowl-shaped body plan
is called a medusa. (Page 419)
Sponges and Cnidarians - Invertebrates

All worms are invertebrates that have long, narrow bodies
without legs. Page 424

Three Phyla of Worms: Flatworm, Roundworm, Segmented Worm.
Page 424

Worms have bilateral symmetry. They have head and tail ends.
They have tissues, organs, and body systems. Page 425

Flat worms are flat and as soft as jelly. Page 426

Many flat worms are parasites. Parasites are organisms that live
inside or on another organism. Parasite takes its food from its
host, the organism in or on which it lives. Page 426

Round worms have a digestive system like a tube, open at both
ends. Page 428
Worms and Mollusks - Invertebrates
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Earth worms and other segmented worms have bodies made up
of many linked sections called segments. Page 429

Segmented worms have a closed circulatory system. In a closed
circulatory system blood moves only within a connected network
of tubes called blood vessels. Page 429

Mollusks are invertebrates with soft, unsegmented bodies that are
often protected by a hard outer shell. All mollusks have the same
basic structure. A soft body often covered by a shell. A mollusk
has a thin layer of tissue called a mantle that covers its internal
organs, and an organ called a foot. In many mollusks, the mantle
produces the hard shell. Depending on the type of mollusk, the
foot has different functions – crawling, digging, or catching prey.
Page 430

The three major groups of mollusks are gastropods, bivalves, and
cephalopods. Page 431-432
Worms and Mollusks - Invertebrates

Arthropods are invertebrates that have an external skeleton, a segmented
body, and jointed attachments called appendages. The major groups of a
arthropods include crustaceans, arachnids, centipedes, and millipedes, and
insects. Arthropods have a waxy, waterproof covering called an exoskeleton.
Page 435

Insects are arthropods with three body sections, six legs, one pair of antennae,
and usually one or two pairs of wings. The three body sections are the head,
thorax and abdomen. Page 439

Head: An insect’s brain and most of its sense organs, such as the eyes and
antennae are in its head.

Thorax: An insect’s midsection, or thorax, is the section to which wings and
legs are attached.
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Abdomen: Inside the abdomen are the many of the insect’s internal organs.
Arthropods - Invertebrates

During complete metamorphosis, an insect goes
through four distinct stages: egg, nymph, the
pupa stage, major changes occur in the body
structure. The stages of gradual metamorphasis
are egg, nymph, larger nymph, and adult.
Nymphs do not change their body structure
significantly, but they do grow larger, and may
molt several times as they become adults.
Beetles, butterflies, flies, and ants undergo
complete metamorphosis. Grasshoppers,
termites, cockroaches, and dragonflies undergo
gradual metamorphosis.
Metamorphosis

Echinoderms are invertebrates with an internal
skeleton and a system of fluid-filled tubes called
a water vascular system. The skin of most
echinoderms is stretched over an internal
skeleton, or endoskeleton, made of hardened
plates. The internal organ system of fluid-filled
tubes in echinoderms is called the water vascular
system. Portions of the tubes in this system can
contract, or squeeze together, forcing water into
structures called tube feet. There are four major
groups of echinoderms: sea stars, brittle stars,
sea urchins, and sea cucumbers. Page 443-445
Echinoderms - Invertebrate

Vertebrates belong to the phylum Chordata.
At some point in their lives, all chordates
have three characteristics: a notochord, a
nerve cord that runs down their back, and
slits in their throat area. Notochord, a flexible
rod that supports a chordate’s back. A
vertebrate has a backbone that is part of an
internal skeleton. This internal skeleton, or
endoskeleton, supports the body and allows
it to move. Page 456-457
What is a Vertebrate?

Fishes, amphibians, and reptiles are ectotherms. An
ectotherm is an animal whose body does not produce
much internal heat. Ectotherms are sometimes called
“coldblooded.” Page 459

A beaver (plus birds, and mammal) would have the
same body temperature whether it is in cool water or
on warm land. The beaver is an example of an
endotherm, an animals whose body regulates its own
temperature by controlling the internal heat it
produces. Page 460
Ectotherms and Endotherms

A fish is a vertebrate that lives in water and uses fins to move.
Most fish are ectotherms and obtain oxygen through gills, which
are on the side of their head, and have scales. Fishes reproduce
sexually. Most fish have external fertilization. In external
fertilization the eggs are fertilized outside the females body.
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Cartilaginous fishes have jaws and scales, and skeletons made of
cartilage.

A bony fish has jaws, scales, a pocket on each side of its head
that holds the gills, and a skeleton made of hard bone.
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Bony fish have an organ called a swim bladder which is an
internal, gas-filled sac that helps the fish stay stable at different
depths in the water.
FISHES (page 462-463)
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Amphibians – after beginning their lives in water,
most amphibians spend their adulthood on land,
returning to water to reproduce. Amphibian means
“double life.” Amphibian is a vertebrate that is
ectothermic.
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The respiratory and circulatory systems of adult
amphibians are adapted for life on land.
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In addition, adult amphibians have adaptations for
moving. Amphibians and other vertebrates that live
on land need a strong skeleton to supports its body.
Most adult amphibians have strong skeletons and
muscular limbs adapted for moving on land.
Amphibians (page 468-471)
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A reptile is an ectothermic vertebrate that has lungs and a scaly skin. Reptiles
have dry, tough skin covered in scales. This scaly skin protects the reptile and
helps keep water in their bodies. Adaptation of the kidneys are; they are an
organ that filters waste from the blood. The wastes are then excretes in a
watery fluid called urine. The kidneys of reptiles concentrate the urine so that
the reptiles lose very little water.
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Both lizards and snakes are reptiles that have skin covered with overlapping
scales.
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Both alligators and crocodiles are large, carnivorous reptiles that care for their
young.
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A turtle is a reptile whose body is covered by a protective shell that includes
the ribs and the backbone.

Extinct reptiles, Dinosaurs, became extinct , or disappeared from Earth about
65 million years ago. Climate change may have caused the extinction of
dinosaurs and other organisms.
Reptiles (page 472-479)
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Paleontologists think that Archaeopteryx and modern birds descended from
some kind of reptile. Scientific name Archaeopteryx meaning, “ancient winged
thing.”
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A bird is an endothermic vertebrate that has feathers and a four chambered
heart.

Bird’s bones are nearly hollow, making the bird lightweight so it can fly in the
air.
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Feathers help birds fly. Birds are the only animal that have feathers. Birds have
a contour feather which is one of the large feathers that give shape to a bird’s
body. Birds have down feathers that are specialized to trap heat and keep the
bird warm.
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Many birds have a storage tank, or crop, for storing food inside the body after
swallowing it. A bird also has a gizzard that squeezes and grinds food because
birds do not have teeth.
Birds (page 480-485)
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All mammals are endothermic vertebrates that have a fourchambered heart and skin covered with fur or hair. Most
mammals are born alive, and every young mammal is fed
with milk produced by organs in its mother’s body.
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Mammals breathe in and out because of the combined
action of rib muscles and a large muscle called the
diaphragm. The diaphragm is located at the bottom of the
ribs.
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Mammals are a very diverse group. The three main groups
of mammals are monotremes, marsupials, and placental
mammals. The groups differ in how they reproduce and
how their young develop.
Mammals (page 486-494)