Unit 5 - Zoology

What is classification in biology?

Putting organisms into groups to organize and study the diversity of life.

Why are common names unreliable?

Different people use different names for the same organism.

What is binomial nomenclature?

A two-name scientific naming system for species.

Who invented binomial nomenclature?

Linnaeus.

What are the two parts of a scientific name?

Genus and species.

How are genus and species written?

Genus capitalized, species lowercase, whole name italicized.

Why does each species have a unique binomial name?

To avoid confusion worldwide.

What rule gives naming priority?

The first validly published name is the official one.

Where must named specimens be stored?

In museums or recognized collections.

What is the biological species concept?

Species are groups that can reproduce with each other but not with others.

Why does this concept have limits?

It does not work well for fossils or asexual organisms.

What is systematics?

The science of classifying organisms.

What is a taxon?

Any named classification group.

List the main classification levels.

Kingdom, Phylum, Class, Order, Family, Genus, Species.

What term replaces “phylum” in plants?

Division.

What defines animals as heterotrophs?

They consume other organisms for energy.

Why do animal cells lack cell walls?

For flexibility and movement.

What is bilateral symmetry?

Right and left halves with head and tail.

What is radial symmetry?

Body parts arranged around a central axis.

What types of skeletal support do animals use?

Water, endoskeletons, or exoskeletons.

What is internal fertilization?

Fertilization inside the body.

What is external fertilization?

Gametes released into the environment.

What is the difference between vertebrates and invertebrates?

Vertebrates have backbones; invertebrates do not.

Core vertebrate traits?

Backbone, cranium, closed circulation, advanced senses.

What is a cloaca?

A shared opening for digestion, excretion, and reproduction.

Define oviparous, ovoviviparous, viviparous.

Egg-laying, eggs hatch inside mother, live birth.

Jawless fish examples and traits?

Lampreys, hagfish; sucker mouths, eel-like bodies

What defines cartilaginous fish?

Skeletons made of cartilage.

What special sense do sharks have?

Lateral line organ.

What makes bony fish successful?

Swim bladder and opercula.

Amphibian life cycle feature?

Metamorphosis between water and land stages

Reptile defining egg structure?

Amniotic egg with amnion.

What does poikilothermic mean?

Body temperature varies with environment.

Dinosaur classification controversy?

Often grouped with reptiles, but closely tied to birds.

Key bird adaptations?

Feathers, beaks, wings, homeothermy, gizzards.

Mammal defining traits?

Hair, mammary glands, differentiated teeth.

Three mammal groups?

Placental, marsupials, monotremes.

What defines arthropods?

Chitin exoskeleton, jointed appendages, segmentation.

Arthropod circulation type?

Open circulation with hemocoel.

Main arthropod body regions?

Head, thorax, abdomen.

Insect defining traits?

Six legs, tracheae, Malpighian tubules.

Holometabolous vs hemimetabolous?

Complete vs incomplete metamorphosis.

What is a coelom?

A body cavity.

Acoelomate vs coelomate?

No cavity vs true cavity.

What is a pseudocoelomate?

Body cavity not fully lined by mesoderm.

What does the blastopore become in protostomes?

Mouth.

What does it become in deuterostomes?

Anus.

Key sponge trait?

No true tissues or organs.

What do collar cells do?

Move water and capture food.

Cnidarian defining weapon?

Cnidocytes with nematocysts.

Roundworm body plan?

Bilateral, pseudocoelomate, no circulation.

Flatworm digestive trait?

One opening only.

Annelid defining feature?

Segmented body with septa.

Mollusk key structures?

Muscular foot, mantle, often a shell.

What is a radula?

Tongue-like feeding structure.

Echinoderm defining systems?

Calcium endoskeleton and water vascular system.

Which phylum includes vertebrates?

Chordata.

Vertebrates are classified as what taxonomic level?

A subphylum.

Why does classification change over time?

New evidence reshapes our understanding.

Why bother with classification at all?

To communicate clearly and understand evolutionary relationships.