Dr.Hayes SU Bio 104 First Test Study Guide

What is artificial selection?

A process initiated by humans to select individuals with certain phenotypical traits.

What is experimental selection?

A method of selecting traits in organisms, often used in agriculture, such as with corn.

What is domestication?

The process by which humans impose selection on species for specific purposes, such as breeding pigeons.

What evidence supports the theory of evolution?

Fossils, which are remnants of once-living organisms.

What conditions are necessary for fossil formation?

Rapid burial by sediment, hardening of minerals, and preservation of organic material.

What is the significance of islands in evolution?

Islands often have species that have never connected to the mainland, leading to unique evolutionary paths.

What are the characteristics of the kingdom Metazoa?

Multicellular, heterotrophic organisms with no cell walls and active movement.

What is the difference between subkingdoms Eumetazoa and Parazoa?

Eumetazoa includes animals with true tissues and symmetry, while Parazoa includes sponges with no true symmetry.

Who is Charles Darwin?

A naturalist who proposed the theory of natural selection and published 'On the Origin of Species' in 1859.

What is natural selection?

The process by which individuals with favorable traits are more likely to survive and reproduce.

What is divergent evolution?

The process where two or more related species become more dissimilar over time, often due to different environments.

What are vestigial structures?

Structures that have no apparent function in a current organism but were functional in ancestral species.

What is biogeography?

The study of the geographic distribution of species and ecosystems.

What is convergent evolution?

The process where unrelated species evolve similar traits due to similar environments or pressures.

What is bio-stratification?

The layering of rock strata that can indicate the relative age of fossils within them.

What is the significance of Archaeopteryx?

A transitional fossil that provides evidence for the evolution of birds from reptiles.

What is Tiktaalik?

A fossil species that represents a link between fish and land-dwelling vertebrates.

What is the half-life in radiometric dating?

The time required for half of a radioactive substance to decay, used to date fossils.

What is the role of homologous structures in evolution?

Structures that are similar in different species due to shared ancestry, indicating evolutionary relationships.

What does the term 'speciation' refer to?

The process by which new species arise from existing species, often through natural selection.

What is the importance of the HMS Beagle voyage?

It was during this voyage that Darwin collected data that led to his theory of evolution.

What is the initial cell formed after fertilization?

Zygote

What is the process called that leads to the formation of a multicellular embryo from a zygote?

Embryogenesis

What stage follows the zygote in embryonic development?

Two-cell stage

What is the solid ball of cells formed during early embryogenesis called?

Morula

What is the name of the stage characterized by the formation of a hollow ball of cells?

Blastula

What is the process called that transforms the blastula into a gastrula?

Gastrulation

What is the term for the opening that forms during gastrulation?

Blastopore

What are the three primary germ layers formed during gastrulation?

Ectoderm, Mesoderm, Endoderm

What is the term for animals that develop the mouth first during embryonic development?

Protostomes

What is the term for animals that develop the anus first during embryonic development?

Deuterostomes

What is the significance of segmentation in animal development?

It allows for redundant organ systems and more efficient movement.

What kingdom do sponges belong to?

Kingdom Animalia

What is the phylum that includes sponges?

Phylum Porifera

What are the two basic body forms of cnidarians?

Polyp and Medusa

What unique structure do cnidarians use to capture prey?

Cnidocytes with nematocysts

What is the term for the jelly-like substance found between the epidermis and the gastrodermis in cnidarians?

Mesoglea

What type of symmetry do eumetazoans exhibit?

Bilateral or radial symmetry

What is the term for animals with two germ layers?

Diploblastic

What is the term for animals with three germ layers?

Triploblastic

What is the larval stage of sponges called?

Parenchymula

What is the role of choanocytes in sponges?

They help in feeding and water circulation.

What is asexual reproduction?

A form of reproduction that does not involve the fusion of gametes.

What is the medusoid stage in cnidarians?

The free-swimming, jellyfish-like stage of the life cycle.

What is the significance of the zygote in reproduction?

The zygote is the fertilized egg that develops into a new organism.

What are the main classes of Cnidarians?

1. Anthozoa (sea anemones, corals) 2. Cubozoa (box jellies) 3. Hydrozoa (hydras, Portuguese Man o' war) 4. Scyphozoa (true jellyfish).

What is unique about the Cubozoa class?

They are strong swimmers and some species can be fatal to humans.

What is the primary characteristic of the Hydrozoa class?

They can exist in both polyp and medusa forms.

What distinguishes the Scyphozoa class?

Jellyfish in this class have a more conspicuous and complex medusa stage.

What are Acoelomates?

Animals that lack a coelom, characterized by bilateral symmetry and high levels of specialization.

What are Ecdysozoans?

Animals that molt their exoskeleton, including arthropods and nematodes.

What are the two large groups of Ecdysozoans?

Arthropods and Nematodes.

What is the significance of the Phylum Platyhelminthes?

It includes flatworms, many of which are parasitic.

What are the two groups of flatworms?

1. Free-living (Class Turbellaria) 2. Parasitic (Class Neodermata).

What is Schistosomiasis?

A disease caused by blood flukes that affects 5% of the world's population.

How do people get infected with Schistosomiasis?

By drinking contaminated water where the larvae penetrate the skin.

What are the characteristics of Phylum Rotifera?

They are bilaterally symmetrical, unsegmented pseudocoelomates with a complete digestive tract.

What is the economic significance of Phylum Mollusca?

Mollusks are an important source of human food and have significant economic value.

What are the main body parts of mollusks?

Mantle, foot, and visceral mass.

What is the role of the mantle in mollusks?

It secretes the shell and covers the body.

What is a tapeworm?

A parasitic flatworm that attaches to the intestinal wall of its host.

What is the life cycle of a tapeworm?

It often involves multiple hosts and can be acquired through ingestion of contaminated food.

What is the function of the suckers in parasitic flatworms?

They help the flatworm attach to the host's body.

What is the primary means of locomotion for many mollusks?

The muscular foot.

What is the primary waste removal organ in mollusks?

Nephridia

What type of circulatory system do mollusks have?

Open circulatory system

What is hemolymph?

The fluid that circulates in the open circulatory system of mollusks.

What is the function of the cilia in nephridia?

To help in the filtration and removal of nitrogenous waste.

What are trochophore larvae?

Free-swimming larval stage found in some mollusks.

What is the second free-swimming larval stage in mollusks called?

Veliger

What are the main classes of mollusks?

Gastropoda, Bivalvia, Cephalopoda, Polyplacophora.

What is unique about the class Cephalopoda?

They have a closed circulatory system and include species like squids and octopuses.

What is torsion in gastropods?

A developmental process that results in the twisting of the body and shell.

What do bivalves use to filter feed?

Siphons to draw water through their bodies.

What is the primary characteristic of class Polychaeta?

They have parapodia, which are paired, fleshy protrusions used for locomotion.

What is the defining feature of annelids?

They are segmented worms with a coelom.

What is the function of the ventral nerve cord in annelids?

It coordinates movement and sensory information.

What type of skeleton do annelids possess?

Hydrostatic skeleton.

What is the role of chaetae in annelids?

They are bristles made of chitin that aid in locomotion.

What are the two subclasses of Class Oligochaeta?

Oligochaeta (earthworms) and Hirudinea (leeches).

What is a common parasitic roundworm that causes trichinosis?

Trichinella spiralis.

What is sexual dimorphism in roundworms?

The physical differences between male and female roundworms.

What is the significance of indirect development in roundworms?

It involves a life cycle that includes larval stages before reaching maturity.

What is the primary habitat of ribbon worms?

Freshwater and terrestrial environments.