12.1 Notes: What is a Vertebrate?

Characteristics of Chordates

  • At some point in their lives, all ______ have 3 characteristics:
  • ______
  • A flexible rod that supports a chordates back
  • Some have for whole life, others develop a true backbone
  • Nerve cord in Back
  • Nerve cord runs down length of back
  • i.e. ______
  • note: worms have a nerve cord, but it does NOT run down their back
  • Slits in throat area
  • Pharyngeal slits (gill slits)- ______
  • ______keep them their entire life
  • Many other vertebrates have them in utero, but they’re gone by birth

Characteristics of Vertebrates

  • A vertebrate has a ______that is part of an ______skeleton
  • The internal (______) skeleton supports the body and allows for movement
  • Backbone (spine)
  • Formed by many similar bones called ______, which are lines up in a row with the spinal cord running through it.
  • Protects spinal cord
  • Allows for flexibility
  • Internal Skeleton (______)
  • Entire internal skeleton (______)
  • Gives body ______, and allows for flexibility
  • Protects internal ______
  • Grows as an animal grows (no molting)

Evolution of Vertebrates

  • First chordates were tiny and marine based (lived in water)
  • By studying fossils and other evidence, such as DNA, scientists have been able to infer the relationships of the major groups of vertebrates- fish, amphibians, reptiles, birds and mammals.
  • The first to appear on earth were probably fish.
  • ______=> ______=> ______=>______=> ______

Keeping Conditions Stable

  • The body temperature of most fish, amphibians and reptiles is close to the temperature of their environment.
  • In contrast, birds and mammals have a stable body temperature that is often warmer than their environment.
  • ______
  • “coldblooded” (only their blood is not actually cold)
  • Fish, amphibians, reptiles
  • Body does NOT produce much internal heat
  • Temperature changes with ______
  • ______
  • “warmblooded”
  • birds and mammals
  • animals whose body regulates its own temperature by ______it produces
  • body temperature is generally ______(doesn’t change much)
  • Have ______glands to help regulate temperature (sweat)
  • Can live in a greater variety of environments

12.1 Notes: What is a Vertebrate?

Characteristics of Chordates

  • At some point in their lives, all chordates have 3 characteristics:
  • Notochord
  • A flexible rod that supports a chordates back
  • Some have for whole life, others develop a true backbone
  • Nerve cord in Back
  • Nerve cord runs down length of back
  • i.e. spinal cord
  • note: worms have a nerve cord, but it does NOT run down their back
  • Slits in throat area
  • Pharyngeal slits (gill slits)- slits on throat area
  • Fish keep them their entire life
  • Many other vertebrates have them in utero, but they’re gone by birth

Characteristics of Vertebrates

  • A vertebrate has a backbone that is part of an internal skeleton
  • The internal (endo) skeleton supports the body and allows for movement
  • Backbone (spine)
  • Formed by many similar bones called vertebrae, which are lines up in a row with the spinal cord running through it.
  • Protects spinal cord
  • Allows for flexibility
  • Internal Skeleton (Endoskeleton)
  • Entire internal skeleton (bones)
  • Gives body shape, support, and allows for flexibility
  • Protects internal organs
  • Grows as an animal grows (no molting)

Evolution of Vertebrates

  • First chordates were tiny and marine based (lived in water)
  • By studying fossils and other evidence, such as DNA, scientists have been able to infer the relationships of the major groups of vertebrates- fish, amphibians, reptiles, birds and mammals.
  • The first to appear on earth were probably fish
  • Fish => amphibians => reptiles =>

birds => mammals

Keeping Conditions Stable

  • The body temperature of most fish, amphibians and reptiles is close to the temperature of their environment.
  • In contrast, birds and mammals have a stable body temperature that is often warmer than their environment.
  • Ectotherms
  • “coldblooded” (only their blood is not actually cold)
  • Fish, amphibians, reptiles
  • Body does NOT produce much internal heat
  • Temperature changes with environmental conditions
  • Endotherms
  • “warmblooded”
  • birds and mammals
  • animals whose body regulates its own temperature by controlling the amount of internal heat it produces
  • body temperature is generally constant (doesn’t change much)
  • Have sweat glands to help regulate temperature (sweat)
  • Can live in a greater variety of environments