zoology midterm

What does the cell theory state?

All living things are made of cells; cells are the basic unit of life; all cells come from pre-existing cells.

Who disproved spontaneous generation?

Redi and Pasteur disproved spontaneous generation.

What type of cells lack a nucleus?

Prokaryotic cells lack a nucleus.

What structures do both prokaryotes and eukaryotes have?

Both contain DNA and ribosomes.

What type of cells contain membrane-bound organelles?

Eukaryotic cells contain membrane-bound organelles.

Where did mitochondria and chloroplasts originate?

They originated from engulfed bacteria (endosymbiotic theory).

How old is the Earth?

The Earth is approximately 4.5 billion years old.

When did life begin on Earth?

Life began approximately 3.5 billion years ago.

What was missing from Earth's early atmosphere?

Oxygen was absent.

What did the Miller-Urey experiment produce?

It produced amino acids.

What were the first life forms like?

They were prokaryotic and anaerobic.

What are homologous structures?

Structures with the same ancestor but different functions.

What are analogous structures?

Structures with the same function but different ancestry.

What are vestigial structures?

Reduced structures with little or no function.

What evidence supports evolution?

Molecular and fossil evidence support evolution.

What is fitness in evolution?

Traits that increase survival and reproduction.

At what level does evolution occur?

Evolution occurs in populations.

What is the bottleneck effect?

A sharp reduction in population size.

What is gene flow?

Movement of alleles between populations.

What is the correct taxonomic order?

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

What is a scientific name?

A two-part name consisting of genus and species.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

Which domain includes protists, fungi, plants, and animals?

Eukarya.

Which organisms were the first eukaryotes?

Protists.

Are most protists unicellular or multicellular?

Most protists are unicellular.

What do plant-like protists do?

They perform photosynthesis.

What are animal-like protists called?

Protozoa.

What does Porifera mean?

Bearer of holes.

What are sponges evolutionarily similar to?

Choanoflagellates.

What type of symmetry do sponges have?

Sponges are asymmetrical.

What is the water flow through a sponge?

Ostia to spongocoel to osculum.

What do sponges eat?

Bacteria, plankton, and particles.

What are the sponge canal types in order?

Asconoid, syconoid, leuconoid.

What are pinacocytes?

Flat outer cells of sponges.

What are porocytes?

Pore cells that allow water entry.

What are choanocytes?

Collar cells that move water and capture food.

What are archaeocytes?

Amoeboid cells in the mesohyl used for digestion and transport.

What cells make spicules?

Sclerocytes.

What cells make collagen?

Collenocytes.

What cells make spongin?

Spongocytes.

How do sponges reproduce asexually?

Budding, fragmentation, and gemmules.

What are gemmules?

Survival structures in freshwater sponges.

Are sponges monoecious or dioecious?

Sponges are monoecious.

Where does sponge fertilization occur?

Internally.

What are Calcarea spicules made of?

Calcium carbonate.

What are Hexactinellida spicules made of?

Silica.

Which sponge class includes most species?

Demospongiae.

What type of symmetry do cnidarians have?

Radial symmetry.

Are cnidarians diploblastic or triploblastic?

Diploblastic.

What does the ectoderm form?

The epidermis.

What does the endoderm form?

The gastrodermis.

What is the mesoglea?

A jelly-like middle layer.

What is a polyp?

A sessile, attached body form.

What is a medusa?

A free-swimming body form.

What is the digestive cavity of cnidarians called?

The gastrovascular cavity.

Is the cnidarian digestive system complete or incomplete?

Incomplete.

What are cnidocytes?

Stinging cells.

What are nematocysts?

Stinging organelles inside cnidocytes.

What type of nervous system do cnidarians have?

A decentralized nerve net.

How do cnidarians exchange gases?

By diffusion.

What role does mesoglea play?

Acts as a hydrostatic skeleton.

How do cnidarians reproduce asexually?

By budding.

How do cnidarians reproduce sexually?

Through external fertilization.

What is the cnidarian larval stage?

Planula.

Which stage is sexual and which is asexual in cnidarians?

Sexual stage is medusa; asexual stage is polyp.

What organisms are in Anthozoa?

Corals and sea anemones.

What is coral bleaching?

The expulsion of zooxanthellae.

What organisms are in Scyphozoa?

Jellyfish.

What organisms are in Cubozoa?

Box jellyfish.

What organisms are in Hydrozoa?

Hydra and Portuguese man-of-war.

Why are coral reefs biodiverse?

They provide habitat, food, and shelter.

How does climate change harm coral reefs?

By causing bleaching.

Are flatworms acoelomate, pseudocoelomate, or coelomate?

Acoelomate.

How do flatworms exchange gases?

By diffusion.

What cells regulate water balance in flatworms?

Flame cells.

What type of digestive system do flatworms have?

Incomplete.

What is the head of a tapeworm called?

Scolex.

Are roundworms pseudocoelomate or coelomate?

Pseudocoelomate.

What type of muscles do roundworms have?

Only longitudinal muscles.

Are most roundworms monoecious or dioecious?

Dioecious.

What disease comes from undercooked pork?

Trichinosis.

What organism causes elephantiasis?

Wuchereria bancrofti.

Do annelids show segmentation?

Yes, true segmentation.

What type of circulatory system do annelids have?

Closed circulatory system.

What class are earthworms in?

Oligochaeta.

What is the function of the gizzard?

Grinding food.

What is the function of the clitellum?

Reproduction.

What are the three main mollusk body parts?

Foot, mantle, and visceral mass.

What is a mollusk shell made of?

Calcium carbonate.

What structure is used for feeding in mollusks?

Radula.

What class do snails belong to?

Gastropoda.

What class do clams belong to?

Bivalvia.

What class do squid belong to?

Cephalopoda.

What larval stage do mollusks and annelids share?

Trochophore larva.