Biology Notes for Unit #6: Kingdom Animalia

I. Phylum Chordata Characteristics – 52,600+ species (Fishes, Amphibians, Reptiles, Aves & Mammals)

  • The chordate name is derived from the Notochord, a firm, flexible rod of specialized cells located in the dorsal region of a chordate body. A few chordates keep the notochord all their lives. In vertebrates, the notochord appears only in the embryonic stage. The notochord is later replaced with a ______(backbone).
  • Chordates are eucoelomate, deuterostomes, with bilateral symmetry.
  • Chordates evolved in the water and possess a tail that extends beyond the anus during their development or life.
  • Chordates possess a Dorsal Nerve Cord, in vertebrates this develops into the ______&______.
  • Chordates possess pharyngeal pouches. Pharyngeal Pouches are small pouches in the anterior part of the stomach. Pharyngeal pouches evolved into filter-feeding parts, which then evolved into gill slits, which later evolved into gills. In land vertebrates, pharyngeal pouches evolved into the ______.

Chordate Subphyla (3)

  1. Urochordata (tunicates or sea squirts) – 2,000+ species
  • Possess a notochord and dorsal nerve cord as a larvae, and gill slits both as a larva and as adults.
  • Most adults are sessile and filter feed.
  1. Cephalochordata (Lancelets) – 30+ species
  • Possess a notochord, dorsal nerve cord, & gill slits as a larvae and adult.
  • Possess poorly developed fins making them poor swimmers. They sit on the bottom filter feed.
  1. Vertebrata (vertebrates) – 42,000+ species
  • The vertebrae (backbone) are the most fundamental difference between vertebrates and invertebrates.
  • The brain and spinal cord (central nervous system)are derived from the embryonic dorsal nerve cord,andis protectedby the skull vertebrae. The cranium vertebrae are derived from the embryonic notochord.
  • Vertebrates possess a closed circulatory system and most often exhibit separate sexes.

7 Classes of Living Vertebrates (with examples listed in order of body complexity)

  1. Agnatha – Jawless fish with a cartilage skeleton (lampreys & hagfish).
  1. Chondrichthyes – Jawed fish with a cartilage skeleton (sharks, rays, mantas).
  1. Osteichthyes – Jawed fish with a bony skeleton (perch, bass, bluegill, etc.), makes up 95% of all fish species.
  1. Amphibians – Bony skeleton animals that live on land and return to the water to lay eggs (frogs, newts, & salamanders).
  1. Reptiles – Bony skeleton animals that live predominately on land where they lay eggs (alligators, lizards, turtles, &

snakes).

  1. Aves – Bony skeleton animals that lay eggs,most have the ability to fly (birds).
  1. Mammals – Bony skeleton animals possessing hair/fur mammary glands to feed young (humans, elephants, whales,

etc.)

Reproductive Strategies

Oviparous – Young are hatched from eggs ______the body.

Ovoviviparous – Young are born alive from eggs ______the body.

Viviparous – Young are born alive attached to a placenta.

A. Fish Characteristics and Classification – 24,000+ species

  • The first known vertebrate (a fish) is the ostracoderm (now extinct). They were made up of bony plates (like shingles) andare first seen in the fossil record about 540 MYA. The bony plates are thought to have evolved into today’s gills. Ostracoderms did not have jaws and most likely poor swimmers. Fish possess 2-chambered hearts.

3 Classes of Fish:

1. Agnatha (also called cyclostomes or round mouths).

  • Examples include hagfish (marine) and lampreys (freshwater).
  • Skeleton is made up of cartilage, ______, possess skin not scales, and most are parasites or scavengers.
  1. Chondrichthyes
  • Examples include sharks, rays, mantas, and skates.
  • Skeleton is ______, they have jaws, most are marine, and most are carnivores.

3. Osteichthyes(95% of all fish)

  • Examples include perch, bass, catfish, bluegill.
  • ______, they have jaws, and live both in marine & freshwater.

Subdivisions of the Bony Fish (osteichthyes):

a) Lobe-Finned – Paddle-like fins w/fleshy bases (coelacanths).

b) Lungfishes – Have lungs as well as gills.

c) Ray-Finned(most common) – Fins supported by long bones

Structure and Functions of a typical Ray-Finned Bony Fish:

Operculum – Protects the gills.

Caudal Fin – Tail, functions to ______.

Dorsal Fin – Top, functions in keeping the fish upright.

Anal Fin – Near anus, functions in keeping the fish upright.

Pelvic Fin – Ventral and Anterior, functions to ______.

Pectoral Fin – Ventral Anterior near operculum, functions to steer, brake, swim backward slowly.

Swim/Air Bladder – A pouch where gases from blood concentrate to give the fish ______.

Integument (skin w/scales) – Protection.

Chromatophores – Pigmented cells used for camouflage (blending in) and mating.

Lateral Line – Cells that sense vibrations and chemicals.

B. Amphibian Characteristics and Terms – 4,600+ species

  • Fish were the only vertebrates for about 150 million years. As competition for food and space increased, natural selectionfavored animals that could spend at least part of their life on land, these animals were the amphibians.

Short-Comings to Evolving Onto Land

  1. Gills stick together and dry out in the air.
  1. Gravity pulls more strongly on skeletal systems because air is less dense than water.
  1. ______
  1. ______
  1. Need for structures to survive in a new environment. Examples ______

Characteristics:

  1. Amphibians are ectotherms (outside heat) or cold-blooded – ______

Because of temperature extremes on land, certain protective behaviors arose in amphibians through natural selection. Manyamphibians enter a state of dormancy/torpor, which is a state of reduced metabolism (body functions slow down).

a)Hibernation – ______

b)Estivation – ______

  1. Amphibians can undergo a metamorphosis in which an aquaticlarval stage matures into a terrestrial adult form.
  1. Amphibians have a mucous secreting skin with no scales.
  1. If an amphibian has feet, they are webbed with the toes lacking claws.
  1. Amphibians use gills, lungs, skin, and mouth in respiration.
  1. Amphibian larvae have ______hearts, adults have ______hearts and well-developed circulation.
  1. Amphibian eggs lack a shell; they are usually laid in water or in a moist environment and fertilized externally.

Anuran/Frog anatomy and adaptations for land and water

  1. Possess 3 eyelids. One eyelid is transparent and keeps the eyeball ______.
  1. The eyes nostrils are located on top of the head allowing a frog to see and breathe above and below the water.
  1. Tympanic membranes (eardrums) are located behind the eyes and function well both in water and in air.
  1. Eustachian tubes are located between the mouth and ears. Eustachian tubes function to equalize air pressure

on both sides of the eardrums, and it also aides in ______.

  1. Mucous membranes keep the skin moist for respiration.
  • How is a frog’s color pattern a positive adaptation? ______

C. Reptiles – 7,100+ species

  • The primary advantages for vertebrates (reptiles)

to make the complete transition to life on land:

______

  • Reproduction on land was now possible due

to the development of the amniotic egg (egg

with a protective membrane and porous

shell enclosing the developing embryo).

Parts of the Amniotic Egg 

Reptile adaptations to terrestrial life

  1. ______

2. ______

3. ______

4. Respiration is performed by internal lungs to stay moist and protected.

5. External structural adaptations such as toes with claws for climbing, running, and other movements on land

  1. Reptilian circulation is more complex than that of amphibians. _____ & _____chambered hearts are used.
  1. Land-dwelling reptiles conserve water by secreting waste in a dry, pasty form as crystals of uric acid.
  • Lizards rely on speed, agility, and camouflage to catch prey and elude predators. Another way lizards elude predators isby being able to release their tails when caught by a predator, this is called autotomy.
  • Snakes locate prey by flicking their tongues and having the chemicals they detect sent to the Jacobson’s organon the roof oftheir mouth. Snakes kill their prey by either:

a)Constriction

b)Swallowing their prey whole

c)Venom

Hemotoxins – ______

Neurotoxins – ______

  • Snakes defend themselves by signals (rattlesnake, viper), camouflage, and coloration (poison warning).
  • Fertilization is internal in snakes and eggs are laid in two ways - Oviparous & Ovoviviparous.

D. Aves (birds) - Birds evolved from reptiles (archaeopteryx fossils and biochemical comparison between birds & dinosaurs)

How Birds are classified – 9,600 + species

* ______

* ______

* ______

Bird Characteristics

  • Possess feathers and thin, hollow bones for flight.
  • Most species forelimbs function as wings used for flight instead of grasping.
  • Two hind limbs with clawed toes are used to support the body.
  • Birds are endotherms (______) and possess a ______heart.
  • Their amniotic eggs are encased in a shell and usually incubated in a nest.

Feathers are modified scales that function in flight and

insulation. Their structure combines maximum

strength with minimum weight.

Preening – Process of a bird cleaning its feathers with an oil secreted by the preen gland found at the base of the

tail.

  • Like reptiles, birds molt. Feathers of flight are replaced in late summer between breeding and migration seasons. Somebirds also undergo a spring molt prior to courtship.
  • Although both birds and reptiles lay yolky eggs, birds generally take better care of their young than reptiles & amphibians do.

Two Methods of Rearing/Raising Young Birds

  1. Precocial – Bird lays many eggs and incubates for a long time. Baby birds are active and fairly independent

shortly after hatching. Chickens, ducks, and quail are examples.

  1. Altricial – Bird lays only a few eggs that hatch quickly. Baby birds are hatched blind and helpless.

Examples includewoodpeckers, hawks, pigeons, owls, robins, cardinals, and blue jays.

Territoriality – ______

Courtship – ______

Ornithologist – ______

  • Birds navigate using stars or the sun and differences in air pressure. Others rely on topographical landmarks like mountains and magnetic cues.

E. Mammals – 4,500+ species

  • Fossil and comparative anatomy evidence points to reptiles being the precursors to mammals. The evolution of mammals from reptiles occurred at least 300 million years ago. About 65 MYA the dinosaurs became extinct. Dinosaur extinction opened new habitats and new food sources, thus reducing the number of competitors to and predators of the mammals.

Mammalian Characteristics:

  1. ______
  1. Possess hair at some time of their lives.
  1. ______
  1. Possess a four chambered heart for efficient distribution of oxygenated blood.
  1. Possess a diaphragm (separates the abdominal and thoracic cavities) for respiration.
  1. ______
  1. Possess a single lower jawbone with specialized teeth (incisors, canines, premolars, & molars – front to back).
  1. ______
  1. Most have keratinized body parts (skin, horns, claws) for protection.

Mammal Classification:

  1. Monotremes – Oviparous animals

Examples - ______

  1. Marsupials – Give birth to tiny immature young that crawl to their mother’s nipple inside her pouch.

Examples - ______

  1. Placentals – Young are carried inside the mother until they can survive in the outside world. The placenta is an

organ formed during pregnancy to supply oxygen and nutrients for the fetus. The placenta also

removes waste from the fetus.

Examples – ______

. Vertebrate II. Systems and Associated Organs: 11 in all

  1. Skeletal – bones, ligaments (connects bone to bone), cartilage (cushions bones)

Functions – Supports and protects organs, gives shape to body, produces blood cells.

  • Ossification – Process of changing a cartilage skeleton to a bony skeleton.
  • Articulation/Joint – ______
  1. Muscular – Muscles, including biceps, triceps, quads, hamstrings, intestines, heart, and blood vessels.

Functions – ______

* Tendon – ______

Muscle Types (3):

a)Cardiac – Involuntary (heart)

b)Smooth – Involuntary (intestines, uterus, blood vessels)

c)Skeletal – Voluntary (all muscles connected to bones)

  1. Integumentary – Skin, hair, fur, scales, nails, claws, feathers, etc.

Functions – Keeps microorganisms out of the body and regulates body temperature.

  1. Circulatory – blood, blood vessels, heart

Functions –Transport nutrients, wastes, hormones

  • Arteries/Arterioles – Carry blood away from the heart
  • Veins/Venules – Carry blood toward the heart
  • Capillaries – Thin vessels where exchange between
  • blood and cells occur. Theyconnect arterioles to venules.

What is Blood?

Plasma – Mostly water, carries the minerals,

vitamins, hormones, wastes, etc.

Erythrocytes (Red Blood Cells) – ______

Leukocytes – (White Blood Cells) – ______

Platelets – ______

  1. Respiratory(airway)Nose/Mouth  Pharynx(throat) Larynx(voice box)

Trachea(windpipe) Lungs(gas exchange)

Functions – Bring oxygen into the body and release carbon dioxide

out of the body, voice.

  1. Lymphatic/Immune – Lymph nodes, tonsils, spleen, and thymus gland

Functions – Defends the body from microorganisms.

  1. Digestive – Mouth  Pharynx  Esophagus  Stomach  Small Intestine  Large Intestine (colon)

Functions – Chemically and physically breakdown food into usable molecules, release solid waste (feces).

  • Liver – Produces bile that breaks down fat.
  • Gallbladder – Stores and concentrates bile.
  • Pancreas – Secretes digestive juices into the small intestine.
  1. Urinary – Kidneys (2)  Ureters (2)  Urinary Bladder  Urethra

Functions – Produces, stores, and releases liquid waste (urine) from the body.

  1. Nervous – Sensory Neurons (detects stimuli) 

Interneurons (interprets stimuli) 

Motor (react tostimuli)

Functions – Communication (receives and sends

messages between the body and the brain)

Main Brain Divisions (parts):

a)Cerebrum – Controls thinking, memory, motor skills, and emotions.

b)Cerebellum – ______

c)Brain Stem – Controls heart rate and respiration

(involuntary functions).

  1. Endocrine – Glands: thymus, testes, ovaries, pituitary, adrenal, etc.

Functions – Communication between body parts using hormones.

  1. Reproductive – Reproductive organs and gametes (eggs & sperm)

Functions – Produce gametes for species survival and hormones for everyday life functions.

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