ANIMAL CHARACTERISTICS CHARACTERISTICS OF ALL ANIMALS Multicellular eukaryotic

ANIMAL CHARACTERISTICS

CHARACTERISTICS OF ALL ANIMALS §Multicellular, eukaryotic organisms. §Reproduce sexually and asexually. §Must undergo cellular respiration in order to produce energy (uses O 2 in a chemical reaction to release energy). §Respond to environmental stimuli.

Animals are classified as vertebrates (having a backbone) invertebrates (not having a backbone).

VERTEBRATES INVERTEBRATE

VERTEBRATES CAN BE FURTHER CHARACTERIZED AS ENDOTHERMS (WARMBLOODED) OR ECTOTHERMS (COLD-BLOODED).

ENDOTHERMS: §“Warm-blooded” §Regulate their internal body temperature. §Body temp stays the same even when the outside temp changes.

ECTOTHERM §“Cold-Blooded” §Animal’s body temp is the same as the outside. §Cannot regulate body temp.

SYMMETRY Most animals have bilateral symmetry- which means they can be divided into right and left halves. These halves are nearly mirror images (i. e. humans).

ANIMALS THAT HAVE BODY PARTS THAT ARE ARRANGED IN A CIRCLE AROUND A CENTER POINT HAVE RADIAL SYMMETRY (I. E. STARFISH).

THE ANIMALS WITH NO DEFINITE SHAPE HAVE ASYMMETRY (I. E. SPONGES).

LOCOMOTION §Animals have different methods of locomotion. § Tube feet are used by starfish for movement. §Squid and octopi use tentacles as a means of movement.

RESPIRATION: EXCHANGING OXYGEN AND CARBON DIOXIDE. §Some vertebrates, such as fish, use gills for respiration §Other vertebrates use lungs. Internal gills External gills

REPRODUCTION Some animals reproduce asexually, by means of budding or fragmentation. Budding occurs when a small part of the parent’s body develops into an independent organism. Hydra Yeast

RED-KNOBBED STARFISH Fragmentation occurs when an organism breaks into two or more parts, each of which may grow into a separate individual.

MOST ANIMALS REPRODUCE SEXUALLY. Some animals that reproduce sexually rely on external fertilization which requires a wet/aqueous environment. (frogs and sponges)

Other animals use internal fertilization for the joining of egg and sperm cells.

DEVELOPMENTAL STAGES Animals may go through a variety of developmental stages. During complete metamorphosis, the fertilized egg becomes a larva, which then changes into a pupa. The adult emerges from the pupal form. A butterfly carries out complete metamorphosis

INCOMPLETE OR GRADUAL METAMORPHOSIS During incomplete or gradual metamorphosis, the fertilized egg becomes a nymph, which looks like a smaller form of the adult. The nymph, after a series of developmental changes becomes the adult. A grasshopper carries out incomplete metamorphosis.

ECOLOGY IS THE STUDY OF HOW LIVING THINGS INTERACT WITH LIVING THINGS IN THEIR ENVIRONMENT IN VARIOUS WAYS. In any environment, all members of a species form a population (ie. all the maple trees in a forest). Two or more populations form a community.

Biotic factors are all living organisms. Ex. of biotic factors are grass, trees, and animals. Abiotic factors are all nonliving things. Ex. of abiotic factors are water, oxygen, carbon dioxide, and rocks. All of the communities (biotic factors) and abiotic factors in an area form an ecosystem.

BIOTIC FACTORS:

An individual’s role in that ecosystem is its niche. A habitat is defined as where an organism lives.

All organisms in an ecosystem are in competition for resources such as food, space, water, light, and air.