Transcript Introduction to Animals

Introduction to Animals
Chapter 32 650-667 blue book
Unit 7 Chapter 25p. 729-744
http://www.animalearn.org/
Chapter 32 Kingdom
Animalia
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Key points
• Id four important characteristics of animals
• List two kinds of tissues found only in
animals
• Explain how the first animals may have
evolved from unicellular organisms
• Id two functions of the body cavity
• List the structural features that
taxonomists use to classify animals
Chapter 32 Kingdom
Animalia
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The Nature of Animals
If you are asked to name an animal, you
might respond with the name of a familiar
large-bodied animal, such as a horse, a
shark, or an eagle. But the kingdom
Animalia is much more diverse than many
people realize!!
Chapter 32 Kingdom
Animalia
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Characteristics
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Multicellular
Heterotrophic organisms
Lack cell walls
Some have a backbone- vertebrates
Some do not have a backboneinvertebrates (95% of all animal species
alive today) (33 phyla)
• Sexual reproduction
Chapter 32 Kingdom
Animalia
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Multicellular Organization
• Specialization- is the evolutionary
adaptation of a cell for a particular
function.
Specialized cells perform particular
functions (digestion, excretion)
Cells tissues organs systems
Allows for the ability to evolve and adapt
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Animalia
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What Animals Do to Survive
– What essential functions must animals perform
to survive?
– Like all organisms, animals must maintain
homeostasis by gathering and responding to
information, obtaining and distributing oxygen
and nutrients, and collecting and eliminating
carbon dioxide and other wastes. They also
reproduce.
Heterotrophy and Movement
• Must eat other organisms
• Ingestion- animal takes in organic
material or food (other living things)
• Digestion- occurs in the animals body
• elimination of wastes
• Most motile some attached
• Nervous tissue (stimuli)
• Muscle tissue- (response)
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Animalia
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Obtaining and Distributing
Oxygen and Nutrients
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After acquiring oxygen and nutrients, animals must transport
them to cells throughout their bodies by using some kind of
circulatory system.
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The structures and functions of respiratory and digestive
systems must work together with circulatory systems.
Gathering and Responding to
Information
– The nervous system gathers information
using cells called receptors that respond to
sound, light, chemicals, and other stimuli.
– Other nerve cells collect and process that
information and determine how to respond.
Sexual reproduction and
development
• Most sexual
• Some asexual (sponges, hydra)
• Zygote- diploid cell produced from 2
haploid cells (mitosis)
• Differentiation- cells become specialized
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Animalia
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Chapter 32 Kingdom
Animalia
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Chordates
– Fewer than 5 percent of animal species are
chordates, members of the clade commonly known
as Phylum Chordata.
– All chordates exhibit four characteristics during at
least one stage of life: a dorsal, hollow nerve cord; a
notochord; a tail that extends beyond the anus; and
pharyngeal pouches.
Invertebrates vs chordates
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Some no body symmetry
Some no true tissue
Some bilateral symmetry
Some specialized parts
NO Backbone!!
Make up most #
(spiders, sponges,
arthropods)
Chapter 32 Kingdom
Animalia
• Notochord- firm, flexible
rod of tissue located in
the dorsal part of the
body (most embryos)
• Dorsal nerve cordhollow tube above the
notochord, will develop
into brain and spinal cord,
• Pharyngeal pouchessmall out pockets of the
anterior digestive track
may develop into gills
used for gas exchange
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Body structure
3 major body plans- animals shape,
symmetry and internal organization
1. Asymmetrical- no symmetry, sponges
2. Radial- body parts organized in a circle
around an axis (sea anemone,
Cnidarians)
3. Bilateral symmetry- two similar halves
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Animalia
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Chapter 32 Kingdom
Animalia
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Body structure
Terms:
• Dorsal (back)
• Anterior (towards head)
• posterior (towards tail)
• ventral (abdomen
• HR clip sect1
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Animalia
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Key points
• Compare symmetry, segmentation, and
body support in invertebrates and
vertebrates
• Describe the differences in the respiratory
and circulatory systems of invertebrates
and vertebrates
• Contrast reproduction and development in
invertebrates and vertebrates
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Animalia
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Invertebrates and vertebrates
Comparative anatomy, the study of the
structure of animal bodies, is one of the
oldest disciplines in biology. Some modern
scientists work to establish the relationship
between different animals, while others try
to establish the relationship between the
form and function of morphological
features of animals and the role of these
features in animal ecology.
Chapter 32 Kingdom
Animalia
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Invertebrate characteristics
Symmetry
• Radial or bilateral
- Segmentation-series of repeating similar units
- cephalization-Animals with bilateral symmetry
typically exhibit, the concentration of sense
organs and nerve cells at their anterior end
(brain)
Support• Simple skeleton
• Fluid-filled body cavity
• Exoskeleton- rigid outer covering
Chapter 32 Kingdom
Animalia
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Invertebrate characteristics
Respiratory/ circulatory system• Gills- organs that consist of blood vessels
surrounded by a membrane specialized for gas
exchange in water, aquatic arthropods, mollusks
• Open circulatory system- fluid pumped by the
heart through vessels and into the body cavity
to vessels (arthropods and some mollusks)
• Closed- blood pumped by a heart and circulates
through the body in vessels that from a closed
loop (Annelids and humans)
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Animalia
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Chapter 32 Kingdom
Animalia
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Invertebrate characteristics
Digestive and excretory system
• Central chambers (one opening,
Cnidarians)
• Gut- digestive tract
• Some wastes excreted as dissolved gas
Nervous system
• Some no neurons (sponges)
• Most neurons
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Animalia
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Invertebrate characteristics
Reproduction and Development
• Sexual reproduction
• Hermaphrodite- organism that produces both
male and female gametes (earthworms)
• Larva- free-living, immature form (indirect
development- does not look like adult)
Zygoteyoung larva older larva  Pupa adult
• Direct development- looks like adult, no larval
stages occur
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Animalia
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Chapter 32 Kingdom
Animalia
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Vertebrate Characteristics
• Have a backbone- fishes, amphibians,
reptiles, birds, and mammals
• Most are terrestrial
• Two broad categories for survival
1. support of the body
2. conserve water
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Animalia
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Question?
• In many animals, the larva is
morphologically and ecologically distinct
from the adult. The larva may live in a
different habitat from the adult, feed on
different foods, or be active at different
times of the day or year. For example,
caterpillars feed on vegetation, while
butterflies feed on nectar. Explain the
possible adaptive advantages of such
ecological differences.
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Animalia
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Vertebrate Characteristics
Segmentation and body support
• vertebrae- repeating bony units of backbone
• endoskeleton- internal skeleton made of bone
and cartilage, backbone, grows as animal grows
Body coveringsintegument, composed of water-filled cells
(death), (for gas exchange moist skinned
animals, water tight birds and reptiles)
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Animalia
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Vertebrate Characteristics
Respiratory and Circulatory system
• Gills in aquatic vertebrates
• Lungs- organs for gas exchange
• Closed circulatory system with a multi chambered heart
Digestive and Excretory system
Mouth  gut  anus
Kidneys- filter wastes from blood, regulate h2o levels
Nervous System- highly organized
Fyi- human digestive track is about 7m or 23ft long
• HR clip sect2
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Animalia
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Key points
• List the steps of fertilization and development
through gastrulation
• List two body parts from each germ layer
• Id the three different body cavity structures of
animals
• Name the categories of animals that undergo
spiral cleavage and radial cleavage
• Contrast the two processes of coelom formation
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Animalia
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Fertilization and Development
development of a multicellular animal from
an egg cell is a truly remarkable process.
Each cell in an animal has the same set of
genes that are used to build the animal ,
yet animals have many different kinds of
cells. From the fertilized egg come large
numbers of cells- trillions in humans- that
consistently give rise to structural features
of the animal body
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Animalia
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Fertilization and early development
• Fertilization is the union of female and male gametes to
form a zygote
• Gametes- egg and sperm
• Cleavage- series of cell divisions
• Blastula- a hollow ball of cells
• Gastrulation – transforms the blastula into a
multilayered embryo call the gastrula
• Archenteron- primitive gut develops, deep cavity in the
embryo
• Blastopore- open end of the archenteron
• Ectoderm- outer germ layer
• Endoderm- inner germ layer
• Mesoderm- forms between the ecto and endo
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Animalia
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Patterns of Embryological
Development
– Every animal that
reproduces sexually
begins life as a
zygote, or fertilized
egg.
– As the zygote begins
to develop, it forms a
blastula, a hollow ball
of cells.
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Animalia
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Patterns of Embryological
Development
– As the blastula develops, it folds in on itself,
forming an elongated structure with a tube
that runs from one end to the other. This tube
becomes the digestive tract.
Patterns of Embryological
Development
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At first this digestive tract has only a single opening. However,
an efficient digestive tract needs two openings.
In phyla that are protostomes, the blastopore becomes the
mouth. In protostomes, including most invertebrates, the anus
forms from a second opening, which develops at the opposite
end of the tube.
Patterns of Embryological
Development
– In deuterostomes, the blastopore becomes
the anus, and the mouth is formed from a
second opening that develops. Chordates and
echinoderms are deuterostomes.
Cleavage and Blastopore Fate
• Some times the blastopore will develop
into a mouth and the second opening
forms the anus  protostomes (mouth
first)
Mollusks, arthropods, annelids
• Sometimes the blastopore will develop into
an anus and the second becomes the
mouth deuterostomes (mouth second)
Echinoderms and chordates
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Animalia
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Chapter 32 Kingdom
Animalia
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Differentiation of Germ Layers
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During embryological development, the cells of most animal
embryos differentiate into three layers called germ layers.
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Cells of the endoderm, or innermost germ layer, develop into
the linings of the digestive tract and much of the respiratory
system.
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Cells of the mesoderm, or middle layer, give rise to muscles
and much of the circulatory, reproductive, and excretory organ
systems.
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The ectoderm, or outermost layer, produces sense organs,
nerves, and the outer layer of the skin.
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Animalia
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Formation of a Body Cavity
– Most animals have some kind of body
cavity—a fluid-filled space between the
digestive tract and body wall.
– A body cavity provides a space in which
internal organs can be suspended and room
for those organs to grow.
Types of cavities
• Acoelomates- do not have a body cavity,
interior of the animal is solid (flatworms)
• Pseudocoleom- false body cavity, not
completely lined by mesoderm
(roundworms)
• Coelom- complete body cavity, mesoderm
lines the body cavity and surrounds and
supports the endodermic gut
Chapter 32 Kingdom
Animalia
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Formation of a Body Cavity
– Most complex animal
phyla have a true
coelom, a body cavity
that develops within
the mesoderm and is
completely lined with
tissue derived from
mesoderm.
Formation of a Body Cavity
– Some invertebrates
have only a primitive
jellylike layer between
the ectoderm and
endoderm.
– Other invertebrates
lack a body cavity
altogether, and are
called acoelomates.
Formation of a Body Cavity
– Still other invertebrate
groups have a
pseudocoelom, which
is only partially lined
with mesoderm.
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Animalia
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Chapter 32 Kingdom
Animalia
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The Cladogram of Animals
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This cladogram presents our current understanding of
relationships among animal phyla.
During the course of evolution, important traits evolved, as shown
by the red circles.
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Animalia
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Animalia
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Animalia
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