Transcript What is an Animal?

Compare and Contrast the Frog and
Perch
What is an Animal?
Chapter 25.1
Characteristics of Animals
• All animals share six characteristics…
– All animals are members of the kingdom Animalia
– All animals are heterotrophic
– All animals are multicellular
– All animals are eukaryotic organisms
– All animal cells lack a cell wall
– All animals have the ability to move
• Animals ability to move from place to place helps
them find food, move to favorable environments, and
avoid predators
• There are many different forms of movement (swim
walk, fly, and running)
• Some animals move by attaching themselves to the
ocean floor or submerged surfaces
Invertebrates vs. Chordates
Invertebrates
• Includes 95% of all animal
species
• Includes all animals that
lack a backbones, or
vertebral column
• Does not form a clade or
any other true category in
the classification system.
(because it talks about
characteristics animals lack)
• Examples: sea stars,
jellyfish, worms, insects
Chordates
• Includes fewer than 5% of
all animal species
• All chordates share four
common characteristics
during at least one stage of
their lives
– 1. ) have a dorsal, hollow
nerve cord
– 2.) have a notochord
– 3.) have a tail that extends
beyond the anus
– 4.) have pharyngeal pouches
Notochord- is a long supporting rod that runs through
the body just below the nerve cord
Pharyngeal Pouches- are paired structures in the throat
region, also called the pharynx.
In fish pharyngeal pouches may turn into gills.
Invertebrates vs. Chordates
Invertebrates
Chordates
• Non-vertebrate chordates
are chordates that lack
vertebrae
• Chordates with backbones
are called Vertebrates
– All Vertebrates have a
cranium and internal
skeleton
– Examples: fishes,
amphibians, reptiles,
birds, and mammals
What Animals Do to Survive
• All animals must perform similar functions to
stay alive.
– 1.) Maintain homeostasis by gathering and
responding to information
– 2.) Obtain and distribute oxygen and
nutrients
– 3.) Collect and eliminate carbon dioxide and
other wastes
– 4.) Reproduce
Maintaining Homeostasis
• Homeostasis is maintained by feedback
inhibition.
• Feedback inhibition (negative feedback)- is a
system in which the product or result of the
process limits the process itself.
• Ex. If your house gets to cold, then your
thermostat turns on the heat. As heat warms the
house the thermostat turns the heater off
Gathering and Responding to
Information
• Complex animals use several linked body systems
to respond to an event
• The nervous system helps respond to events by
using cells called receptors
– Receptors respond to light, chemicals, sound and other
stimuli
– Other nerve cells process the information and
determine how to respond
– Animals often respond by moving around
– Muscle tissues generate force by becoming shorter
when stimulated by the nervous system
– Muscles work together with the skeleton to make up
the musculoskeletal system
Gathering and Responding to
Information
• Skeletons vary widely from phylum to phylum
– Invertebrates have skeletons that are flexible and
function through the use of fluid pressure
– Can have either Internal or external skeletons
• Internal skeletons are made from the bones of the
vertebrae (found inside the body)
• External skeletons are found outside the body
•
•
External Skeleton
Internal Skeleton
Obtaining and Distributing Oxygen and
Nutrients
• All animals must breathe to obtain oxygen
– Small animals obtain oxygen by allowing it to diffuse
across their skin
– Larger animals use gills, lungs, or air passages
• All animals must eat to obtain nutrients
• Nutrients and oxygen are distributed to cells
throughout the body using a circulatory system
• The structures of the respiratory and digestive
system work together with the circulatory system
Collecting and Eliminating CO2 and
Other Wastes
• Animals’ metabolic processes create carbon
dioxide and other waste products that contain
nitrogen often in the form of ammonia
• Carbon dioxide and ammonia are toxic and must
be excreted and eliminated from the body
• Many animals remove CO2 with their respiratory
system. More complex animals have a specialized
organs system for eliminating waste called the
excretory system
• Before wastes can be eliminated they need to be
collected from cells throughout body tissues and
then delivered to the excretory or respiratory
system
Reproducing
• Most animals reproduce sexually by producing
haploid gametes.
• Sexual reproduction creates and maintains genetic
diversity.
– Genetic diversity increases a species’ ability to evolve
and adapt as the environment changes
• Invertebrates and a few vertebrates reproduce
asexually
– Asexual reproduction produces offspring that are
identical to the parent
– Asexual reproduction allows animals to increase their
numbers rapidly , but does not generate genetic
diversity
25.1 Vocabulary
• Invertebrates- includes all animals that lack a back
bone or vertebral column
• Chordates- animals that have had a dorsal, hollow
nerve cord, a notochord, a tail that extends beyond the
anus, and pharyngeal pouches during at least one stage
of their life
• Notochord- is a long supporting rod that runs through
the body just below the nerve cord
• Pharyngeal Pouches- are paired structures in the
throat region, also called the pharynx.
• Vertebrates- chordates with backbones
• Feedback Inhibition- also known as negative feedback,
is a system in which the product or result of the
process limits the process itself
• Using a new Venn Diagram
compare and contrast
Chordates and Invertebrates…