Zoology: The Study of Animals

Animal: a multi-cellular, heterotrophic organism, with cells protected by cell membranes, utilize aerobic respiration, and have some form of movement

Animal Characteristics

1. Multi-cellular: cell specialization – the adaptation of cells for a specific function Ex. Neuron, muscles, bone, etc.

2. Heterotrophic: do not make their own food – consume other animals or plants

3. Sexual Reproduction: exchange of genetic information in which two haploid cells unite to form a diploid cell

4. Aerobic Respiration: breaking down carbohydrates into usable energy -Performed by the mitochondria -Turns glucose and oxygen into ATP -By product Carbon Dioxide – we breath this out

5. Movement: specialized cells form neural tissue that sends electrical responses to muscle tissue

Two Groups of Animals:

1. Invertebrates: animals without a central nervous cord and back bone

2. Vertebrates: animals that have a central nervous cord and a backbone

Animal Bodies – terms and concepts

1. Morphology: study of internal/external structures and form and function

2. Body Reference Terms: dorsal and ventral; anterior and posterior

3. Symmetry: pattern or structure in reference to balance (3 types) Asymmetry: no balance of body parts or shapes Ex. Sponges

3. Symmetry: pattern or structure in reference to balance (3 types) Radial Symmetry: similar parts branch out in all directions Ex. Jellyfish, starfish

3. Symmetry: pattern or structure in reference to balance (3 types) Bilateral Symmetry: animals with two similar halves on either side of a plane Ex. Mammals, birds, reptiles, etc.

4. Cephalization: animals with a head area with sensory organs and a brain

Invertebrate Characteristics:

1. Display all forms of symmetry

2. Segmentation: repetition of similar units

3. Exoskeleton: rigid outer covering of the soft tissue -must molt (shed) their exoskeleton -legs out the side, not underneath

4. Respiration and circulatory system Respiration: gills or lungs used for gas exchange Circulation: open circulatory system – no blood vessels

5. Digestive and Nervous system

6. Reproduction: sexual and asexual-Hermaphroditic: produces male and female gametes

7. Indirect Development: animals that have intermediate larval stage Ex. Egg  Larva pupa  adult

Vertebrate Characteristics

1. Endoskeleton: legs under the body

2. Integument: outer body covering of the animal (skin, scales, fur, etc.)

3. Respiration - lungs

4. Kidneys: excretory system

5. Sexual Reproduction (eggs and sperm)

6. Closed circulatory system (blood vessels)

Adaptations to Reproduction 2 Basic Process For Survival Metabolism: insures the survival of the individual Reproduction: insures survival of the species

2 Modes of Reproduction

1. Asexual: creation of a new individual whose genes come from one parent Fission: separation of parent organisms

2. Sexual: exchange of haploid gamets

Unusual Reproductive Processes

1. Same Sex Species: species that reproduce with only one sex Parthenogenesis: eggs that develop without being fertilized

2. Sex Reversal: species that start life as one sex and end as another Ex. Wrasses Fish

3. Male Parasitism: males attach themselves to females as a parasite for life

4. Gastric Brooding: eggs are carried in the stomach of the mother

5. Hermaphrodites: organism has both male and female sex organs

Mechanisms of Reproduction Fertilization: the fusion of two haploid gametes to form a diploid zygote 2 Types: External Fertilization: fertilization that takes place outside of the body (aquatic organism) Internal Fertilization: male deposits sperm directly inside the female’s body (terrestrial organism)

Amniote Egg: developing embryo surrounded by a liquid sac called an amnion -1st appeared with the evolution of reptiles -allowed for the colonization of land by animals

Courtship: animal behavior that attracts a mate

-vocalizations

-dancing

-coloration

-biting

-Pheremones: chemical signal released by one organism that influences another’s behavior

Sexual Reproductive Types

1. Viviparous: fertilized eggs develop in the uterus; nourished by placenta

2. Oviparous: internal fertilization but eggs are laid outside the body

3. Ovoviviparous: eggs retained in the oviduct– young nourished by a yolk sac

Embryology:

Blastula: a hollow ball of cells in rapid mitosis

Gastrulation: the process in which blastula transforms into a multi-layered embryo

Creates 3 germ layers Ectoderm: outer most cell layer – becomes the skin Endoderm: inner most cell layer –becomes the internal organs Mesoderm: middle cell layer – becomes the limbs

Animal Body Types

1. Acoelomate: lacking a body cavity

2. Pseudocoelomate: intestinal tract is suspended in a fluid coelom

3. Coelomate: animals with true body cavities – mesoderm lines the cavity