Scientists have warned doctors of the danger of their increasing use of antibiotics (for instance, penicillin) for treating minor illnesses. They are concerned because

Strains of microorganisms that are resistant to these drugs will increase.

Which one of the following was an assumption of Charles Darwin's theory of natural selection?

Populations produce more offspring than their environment can support.

A group of individuals of the same species occupying a given is called

Population.

In a population of bears, which is most likely to be considered to have the greatest Darwinian fitness?

The bear that leaves the most descendants.

The phrase Darwin used to describe his broad theory of evolution is "descent with __________."

Modification.

All of life is related through common ancestry, accounting for the __________ of life.

Unity.

The __________ of life arises from the adaption of species to different habitats over long spans of time.

Diversity.

Darwin proposed a mechanism for how evolution occurs, which he called

Natural selection.

Two key observations underlying natural selection are that members of a population vary in their __________ and that all species can produce more offspring than their environment can support.

Inherited traits.

Darwin inferred that most organisms with traits best suited to their environment tend to leave more __________ than other members of a population.

Offspring.

This unequal reproduction in a population leads to the gradual accumulation of __________ to the environment.

Adaptions.

The wing of a bat is homologous to the __________ of a whale.

Flipper.

Population's increase in the frequency of traits suited to the environment.

Evolutionary adaption.

Provide an alternative definition of evolution.

all of biological history; from the earliest microbes to the enormous diversity of organisms that live on Earth today.

Darwin's phrase for evolution, __________ with __________, captured the idea that an ancestral species could diversify into many descendant species by the accumulation of different __________ to various environments.

Descent; modification; adaptions.

Why are older fossils generally in deeper rock layers than younger fossils?

Sedimentation places younger rock layers on top of older ones.

Ordered sequence of fossils as they appear in the rock layers, marking the passage of geologic time.

Fossil record.

Geographic distribution of species, that first suggested to Darwin that today's organisms evolved from ancestral forms.

Bioeography.

Comparison of body structures in different species.

Comparative anatomy.

Similarity due to common ancestry.

Homology.

Remnants of features that served important functions in the organism's ancestors.

Vestigial structures.

Name the five lines of evidence for evolution presented in this section.

Fossil record; bioeography; comparative anatomy; comparative embryology; molecular biology.

How did Darwin hypothesize that adaption is related to the origin of new species?

Populations in different environments adapt to local conditions and, over time, may become dissimilar enough to be considered different species.

Explain why the following phrase is incorrect. "Pesticides cause pesticide-resistance in insects."

An environmental factor does not create new traits such as pesticide resistance, but favors traits that are already represented in the population.

The total collection of alleles in a population at any one time; total of all the alleles in all the individuals making up the population.

Gene pool.

Which process, mutation or sexual reproduction, results in most of the generation-to-generation variability in human populations? Why?

Sexual reproduction; humans have a relatively long generation span and mutations have relatively little effect in a single generation.

Evolution viewed on the smallest scale.

Microevolution.

A change in the gene pool or a population due to chance.

Genetic drift.

Genetic drift due to drastic reduction in population size.

Bottleneck effect.

Would you expect modern cheetahs to have more genetic variation or less genetic variation than cheetahs did 1,000 years ago?

Less, because the bottleneck effect reduces genetic variability.

Which mechanism of microevolution has been most affected by the increased ease of people traveling throughout the world?

Gene flow.

New population whose gene pool differs from that of the parent population.

Founder effect.

The contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals.

Relative fitness.

Shifts overall makeup of a population by selecting in favor of one extreme phenotype.

Directional selection.

Can lead to balance between two or more contrasting phenotypes in a population.

Disruptive selection.

Favors intermediate phenotypes; typically occurs in relatively stable environments where conditions tend to reduce physical variation.

Stabilizing selection.

What is the best measure of relative fitness?

The number of fertile offspring an individual leaves.

Form of natural selection in which individuals with certain traits are more likely than other individuals to obtain mates.

Sexual selection.

Distinction in appearance; often manifested in a size difference.

Sexual dimorphism.

What were the two proposals made by Darwin in his The Origin of Species?

1. Existing species descended from ancestral species.

2. Natural selection is the mechanism of evolution.

Represents a succession of related species, with the most recent at the tips of the branches; each branch represents a common ancestor of all species that radiate from it.

Evolutionary trees.

Define fitness from an evolutionary perspective.

Measured by the relative number of alleles that it contributes to the gene pool of the next generation compared with the contribution of others; thus the number of fertile offspring produces determines an individual's fitness.

The processes of __________ and __________ generate variation, and __________ produces adaptation to the environment.

Sexual reproduction; mutation; natural selection.

As a mechanism of evolution, natural selection can be most closely equated with

Unequal reproductive success.

The oldest fossils have been dated to be approximately how many years old?

3.5 billion.

The fauna and flora of Australia are very different from those of the rest of the world. Why might this be true?

Australia has been isolated for about 50 million years.

Which one of the following is the correct presentation of a species name?

Homo erectus.

Put the following in order, beginning with the most general: class, family, genus, kingdom, order, phylum, species.

Kingdom, phylum, class, order, family, genus, species.

What do phylogenetic trees represent?

The evolutionary relationships among organisms.

The naming and classifying of organisms is called

Taxonomy.

Biological species consist of groups of

Populations.

Cladistic analysis indicates that crocodiles are more closely related to __________ than __________.

Birds; lizards.

The wing of a bald eagle is __________ to the wing of a penguin.

Homologous.

The wing of a penguin is __________ to the flipper of a dolphin.

Analogous.

Molecular systematics might include all of the following EXCEPT

Anatomical similarities.

Cladistic analysis identifies clades on the basis of

Homologous structures unique to each group.

Two animals are considered members of different species if they

Cannot produce viable, fertile offspring.

Define Adaptive Radiation.

Rapid speciation under conditions in which there is little competition.

_______________ create conditions that promote adaptive radiation.

Mass extinctions.

The appearance of an evolutionary novelty promotes

Adaptive radiation.

In the late 1900s, molecular studies and cladistics led to the development of a __________ classification system.

Three-domain.

Animals that possess homologous structures probably

Shared a common ancestor.

The process in which one species splits into two or more species.

Speciation.

Defines species as a group of populations whose members have the potential to interbreed with one another in nature to produce fertile offspring.

Biological species concept.

Anything that prevents individuals of closely related species from interbreeding.

Reproductive barriers.

Things that prevent mating or fertilization between species.

Prezygotic barriers.

Operate if interspecies mating actually occurs and results in hybrid zygotes.

Postzygotic barriers.

Why is behavioral isolation considered a prezygotic barrier?

Because it prevents mating and therefore the formation of a zygote.

In _______________, the initial block to gene flow is a geographic barrier that physically isolates the splinter population.

Allopatric speciation.

The origin of a new species without geographic isolation.

Sympatric speciation.

What mechanism accounts for most observed instances of sympatric speciation?

Accidents of cell division that result in polyploidy; produces "instant" reproductive isolation.

Describes long periods of little apparent change (equilibria) interrupted (punctuated) by relatively brief periods of rapid change.

Punctuated equilibria.

A new species changes most as it first branches from a parent species; little change for the rest of the species' existence.

Punctuated pattern of speciation.

Species that are descended from a common ancestor diverge gradually in form as they acquire unique adaption.

Gradual pattern of speciation.

Evolutionary change above the species level, including the origin of evolutionary novelty and new groups of species, and the impact of mass extinctions on the diversity of life and its subsequent recovery.

Macroevolution.

Commonly referred to as Evo-devo.

Evolutionary developmental biology.

The retention into adulthood of features that were solely juvenile in ancestral species.

Paedomorphosis.

Divides Earth's history into sequence of geological periods.

Geologic time scale.

Method based on the decay of radioactive isotopes, including isotopes of carbon, potassium, and uranium; established the dates in the geologic time scale.

Radiometric dating.

Discipline of biology that focuses on classifying organisms and determining their evolutionary relationships.

Systematics.

The identification, naming, and classification of species.

Taxonomy.

Biologists use _______________ to depict hypotheses about the evolutionary history of species.

Phylogenetic trees.

Similarity due to convergence.

Analogy.

Consists of an ancestral species and all its evolutionary descendants-- a distinct branch in the tree of life.

Clade.

What are the three domains?

Bacteria, Archaea, and Eukarya.

What lines of evidence cause biologists to develop the three-domain system of classification?

Molecular studies and cladistics.

Why is a small, isolated population more likely to undergo speciation than a large one?

A small gene pool is more likely to be changed substantially by genetic drift and natural selection.

Structures that originally had one use but became adapted for different functions.

Exaptation.

Mass extinctions were followed by __________ of the survivors.

Diversification.

The animals and plants of India are almost completely different from the species in nearby Southeast Asia. Why might this be true?

India was a separate continent until relatively recently.

In the three-domain system, which two domains contain prokaryotic organisms?

Archaea; bacteria.

The early atmosphere on Earth is thought to have had very little, if any, __________.

O2.

The earliest cells were most likely __________.

Prokaryotic.

Methanogens, extreme halophiles, and extreme thermophiles are examples of __________.

Archaea.

A major difference between eukaryotes and prokaryotes is that ______________________________.

Eukaryotes' survival is limited to a few environments whereas prokaryotes have adapted to a variety of environments.

A major difference between eukaryotes and prokaryotes is that __________.

Algae.

Which group of algae is most closely related to higher plants?

Multicellular green algae.

The evolutionary link between unicellular and multicellular life was probably ____________________.

Development of colonial forms where unicellular protists stick together.

The most abundant group of organisms on Earth is the __________.

Prokaryotes.

The bacteria initially persist in the predatory cell because

The predatory cell is unable to digest the bacteria.

The abiotic synthesis of _______________, such as amino acids and nitrogenous bases, may have occurred near volcanoes or around deep-sea vents.

Small organic molecules.

The abiotic synthesis of __________ may have occurred as organic monomers splashed onto hot rocks and spontaneously joined into chains.

Polymers.

The first __________ may have formed when collections of organic molecules became isolated within membranes.

Protocells.

The first genetic material was probably self-replicating _____.

RNA.

Once some protocells contained self-replicating molecules, ___________ could have begun to shape their properties, as those that reproduced more efficiently would have increased in number.

Natural selection.

At some point, _____, a more stable molecule, became the genetic material.

DNA.

The earliest evidence of life on Earth is 3.5 billion-year-old fossils of __________, which were built up by ancient photosynthetic prokaryotes.

Stromatolite.

According to one of the main hypotheses for the origin of life, what must have come first?

Abiotic synthesis of organic molecules.

Early pre-cells developed an important prerequisite for life, which was self-replicating _____.

RNA.

E. coli bacteria, which live in human intestines, are shaped like tiny, straight sausages. They are _________.

Bacilli.

Which organism is characterized by having glassy cell walls that contain silica?

Diatom.

What is the correct sequence of the appearance of the four major groups of plants in the fossil record from most ancestral to most recent?

Byrophytes, seedless vascular plants, gymnosperms, angiosperms.

What adaptation contributed to the ability of bryophytes to colonize land?

Waxy cuticle.

What is the function of vascular tissue in plants?

To conduct water and nutrients throughout the plant.

The main evolutionary advantage of pollen is ____________________.

The ability to transport male gametes without water.

Give an example of an angiosperm?

Oak tree.

Describe one difference between plants and fungi.

Fungi are heterotrophic and plants are autotrophic.

Which characteristic is shared by algae and seed plants?

Chloroplasts.

The uptake of small nutrient molecules from the environment is known as __________.

Absorption.

One of many filaments making up the body of a fungus is called a __________.

Hypha.

The densely branched network of fungal filaments is a __________.

Mycelium.

A __________ is a close association of fungi and plant roots that is beneficial to both.

Mycorrhizae.

An organism that derives its nutrition from a living host is called a __________.

Parasite.

You are a plant physiologist specializing in how humidity affects water transport in white pines. What would you study?

Xylem.

The trees in a forest all have closed stomata. What would be the cause of this?

Drought.

What would happen to a tree in an environment devoid of carbon dioxide?

It would starve.

You open your refrigerator and grab some broccoli for a snack. It has a pungent, sharp smell. What causes this?

Sulfur compounds.

Your aunt lives in Iowa. What is likely the biggest problem she faces when she tries to grow broccoli?

The climate is too hot.

At the grocery store, you notice the broccoli is yellowish. What likely caused this?

The flowers opened.

Fresh broccoli should have what kind of taste?

Sweet.

Cabbage is a very close relative of broccoli. Thus cabbage is what?

Cruciferous.

List three common characteristics of all plants.

Multicellular, eukaryotic, and photoautotrophic.

Plants first colonized land at least __________ years ago.

475 million.

The earliest organisms were all __________, their cells lacking true __________.

Prokaryotes; nuclei.

__________ are composed of one or more cells that contain nuclei and many other organelles absent in __________ cells.

Eukaryotes; prokaryotic.

One reason why the spontaneous generation of life on Earth could not occur today is the abundance of __________ in our modern atmosphere.

Oxygen.

Abiotic synthesis of organic monomers occurs in which stage of the four-stage hypothesis for the origin of life?

Stage 1.

Abiotic synthesis of polymers occurs in which stage of the four-stage hypothesis for the origin of life?

Stage 2.

The packaging of molecules into pre-cells occurs in which stage of the four-stage hypothesis for the origin of life?

Stage 3.

The origin of self-replicating molecules occurs in which stage of the four-stage hypothesis for the origin of life?

Stage 4.

Droplets with membranes that maintained an internal chemistry different from the surroundings.

Pre-cells.

What is the name of the chemical reaction whereby monomers are linked together into polymers?

Dehydration reaction.

What are ribozymes? Why are they a logical step in the formation of life?

RNA molecules that function as an enzyme; can perform some of the functions of both DNA and protein.

Rod-shapred prokaryotes are called __________. Singular __________.

Bacilli; bacillus.

Spherical prokaryotic cells are called __________. Singular __________.

Cocci; coccus.

Mass of branching chains of rod-shaped cells.

Actinomycete.

Photosynthetic __________ exhibits division of labor.

Cyanobacteria.

The cells copy their DNA almost continuously and divide again and again by the process of __________.

Binary fission.

In many natural environments, prokaryotes attach to surfaces in a highly organized colon called a __________.

Biofirm.

A(n) __________ is a thick-coated, protective cell produced within the prokaryotic cell when the prokaryote is exposed to unfavorable conditions.

Endospore.

Using a microscope, how could you distinguish the cocci that cause staph infections from those that cause strep throat?

By the arrangement of the aggregates: grape-like clusters for staphylococcus and chains of cells for streptococcus.

Why do microbiologists autoclave their laboratory instruments and glassware rather than just washing them in very hot water?

To kill bacterial endospores, which can survive boiling water.

A bacterium requires only water and the amino acid methionine to grow and lives in very deep caves where no light penetrates. Based on its mode of nutrition, this species would be classified as __________.

Chemoheterotrophs.

These organisms are photosynthesizers that use light to drive the synthesis of organic compounds from CO2; includes plants and algae.

Photoautotrophs.

What is the carbon source of photoautotrophs? The energy source?

CO2; sunlight.

These organisms extract energy from inorganic substances such as ammonia, NH4; all are prokaryotes.

Chemoautotrophs.

What is the carbon source of chemoautotrophs? The energy source?

CO2; inorganic chemicals.

These organisms harness energy from light but must obtain carbon in organic form; all are prokaryotes.

Photoheterotrophs.

What is the carbon source of photoheterotrophs? The energy source?

Organic compounds; sunlight.

These organisms consume organic molecules for both energy and carbon; includes some prokaryotes and protists and all fungi and animals.

Chemoheterotrophs.

What is the carbon source of chemoheterotrophs? The energy source?

Organic compounds; organic compounds.

Bacteria and other organisms that cause disease are called

Pathogens.

__________ are proteins that bacterial cells secrete into their environment.

Exotoxins.

Chemical components of the outer membrane of certain bacteria.

Endotoxins.

How can an exotoxin be harmful even after bacteria are killed?

They are secreted poisons that can remain harmful even when the bacteria that secrete them are gone.

The use of organisms to remove pollutants from water, air, or soil.

Bioremediation.

How do bacteria help restore the atmospheric CO2 required by plants for photosynthesis?

By decomposing the organic molecules of dead organisms and organic refuse such as leaf litter, bacteria release carbon from the organic matter in the form of CO2.

Which organelles of eukaryotic cells probably descended from andosymbiotic bacteria?

Mitochondria and chloroplasts.

Catch-all category that includes all eukaryotes that are not fungi, animals, or plants.

Protist.

Close association between organisms of two or more species; "living together".

Symbiosis.

__________ refers to one species living inside another host species.

Endosymbiosis.

Protists that live primarily by ingesting food are called __________.

Protozoans.

Protozoans that move by means of one or more flagella.

Flagellates.

What three modes of locomotion occur among protozoans?

Movement using flagella, cilia, and pseudopodia.

_______________ are named for the feeding stage in their life cycle, an amoeboid mass called a plasmodium.

Plasmoidial slime molds.

The feeding stage of a _______________ consists of 1. Solitary amoeboid cells, or swarming together to form 2. Slug-like colony functioning as a single unit and 3. Extends a stalk and develops into a multicellular reproductive structure.

Cellular slime molds.

Which protozoans are most similar intheir movement to the unicellular stage of slime molds?

Amoebas.

What metabolic process mainly distinguishes algae from protozoans?

Photosynthesis.

Are seaweeds plants?

No, they are large, multicellular marine algae.

Communities of organisms, mostly microscopic, that drift or swim weakly near the surfaces of ponds, lakes, and oceans.

Plankton.

Each __________ species has a characteristic shape reinforced by external plates made of cellulose; abundant in the aquatic pastures of plankton.

Dinoflagellate.

Defined as large, multicellular marine algae, __________ grow on rocky shores and just offshore beyond the zone of the pounding surf.

Seaweeds.

Place the following events in the history of life on Earth in the order that they occurred.

-Colonization of land by animals- colonization of land by plants and fungi- diversification of animals (Cambrian explosion)- origin of eukaryotes- origin of humans- origin of multicellular organisms- origin of prokaryotes.

1. Origin of prokaryotes 2. Origin of eukaryotes 3. Origin of multicellular organisms 4. Diversification of animals 5. Colonization of land by plants and fungi 6. Colonization of land by animals 7. Origin of humans.

What is the difference between autotrophs and heterotrophs in terms of the source of their organic compounds?

Autotrophs make their own organic compound from CO2, while heterotrophs must obtain at least one type of organic compound from another organism.

__________ distinguishes plants from the animal and fungal kingdoms.

Photosynthesis.

Plants are specialized to take advantage of all resources necessary to photosynthetic organisms by having both aerial leaf-bearing organs called __________ and subterranean organs called __________.

Shoots; roots.

__________ are key adaptations that made it possible for plants to live on land.

Mycorrhizae.

An important terrestrial adaptation of plants is __________, a chemical that hardens cell walls.

Lignin.

The terrestrial equipment of most plants includes _______________, a system of tube-shaped cells that branch throughout the plant.

Vascular tissue.

The vascular tissue has these two types of tissues specialized for transport:

Xylem and phloem.

Consists of dead cells with tubular cavities for transporting water and minerals from roots to leaves.

Xylem.

Consists of living cells that distribute sugars from the leaves to the roots and other non-photosynthetic parts of the plant.

Phloem.

A __________ has a jacket of protective cells surrounding a moist chamber where gametes can develop without dehydrating.

Gametangia.

Plants and present-day __________ probably evolved from a common ancestor.

Charophytes.

Nonvascular plants lacking true roots and leaves, and also lignin, resulting in weal upright support, including mosses, liverworts, and hornworts.

Bryophytes.

A __________ consists of an embryo packaged along with a store of food within a protective covering.

Seed.

Today, the most widespread and diverse __________ are the __________, consisting mainly of cone-bearing trees, such as pines.

Gymnosperms; conifers.

Name the four major groups of plants.

Bryophytes; ferns; gymnosperms; angiosperms.

If you examine a mat of moss closely, you can see two distinct forms. The green, sponge-like plant called the __________ and the __________, growing out as a stalk with a capsule at its tip.

Gametophyte; sporophyte.

A __________ is a haploid cell that can develop into a new individual without fusing with another cell.

Spore.

Bryophytes, like all plants, have a life cycle that involves an alternation of generations. What are the two generations called? Which generation dominates?

Gametophyte and sporophyte; gametophyte.

Why are ferns able to grow taller than mosses?

Vascular tissue hardened with lignin allows ferns to stand taller and transport nutrients faster.

What are the three additional adaptations of gymnosperms that make survival in diverse terrestrial habits possible?

Further reduction of the gametophyte; pollen; seeds.

What are the four main parts of a flower?

Sepal; petal; stamen; carpel.

Name three ways that we benefit from fungi in our environment.

Help recycle nutrients by decomposing dead organisms; Mycorrhizae help plants absorb water and nutrients; some fungi serves as food.

Minute threads of cytoplasm surrounded by a plasma membrane and cell wall.

Hyphae.

Describe how the structure of a fungal mycelium reflects its function.

The extensive network of hyphae puts a large surface area in contact with a food source.

Symbiotic associations of unicellular algae or photosynthetic bacteria held in a mass of fungal hyphae.

Lichens.

Which of the following structures is common to all four major plant groups: vascular tissue, flowers, seeds, cuticle, or pollen?

Cuticle.

Angiosperms are distinguished from all other plants because only angiosperms have reproductive structures called

Flowers.

Gametophyte is to haploid as __________ is to diploid.

Sporophyte.

__________ are to conifers as flowers are to __________.

Cones; angiosperms.

Ovule is to seed as ovary is to __________.

Fruit.

Under a microscope, a piece of a mushroom would look most like

A tangle of string.

During the Carboniferous period, the dominant plants, which later formed the great coal beds, were mainly

Ferns and other seedless vascular plants.

You discover a new species of plant. Under the microscope, you find that it produces flagellated sperm. A genetic analysis shows that its dominant generation has diploid cells. What kind of plant do you have?

A fern.

Plant diversity is greatest where?

Tropical forests.

A ripened ovary of a flower that protects and aids in the dispersal of seeds.

Fruit.

Lichens are symbionts of photosynthetic __________ with __________.

Algae; fungi.

The major changes recorded in the history of life over vast tracts of time.

Macroevolution.

The earth formed about __________ years ago.

4.6 billion.

The earliest evidence of life on earth comes from fossils that are about _____ billion years old.

3.5

Scientific evidence indicates that earth and the other planets of our solar system formed about __________ years ago from a vast swirling cloud of dust.

4.6 billion.

Layered rocks that result from activities of prokaryotes that blind thin films of sediment together.

Stromatolite.

Because __________ is not a simple process, it suggests that life evolved earlier than the first prokaryotes, perhaps as much as 3.9 billion years ago.

Photosynthesis.

The formation of __________, __________, and __________ molecules represent stages in the origin of the first cells.

Polymers; membranes; self-replicating.

The origin of self-replicating molecules allows for __________.

Inheritance.

Some RNA molecules called __________, can carry out enzyme like functions.

Ribozymes.

The entire 4.6 billion years of Earth's history can be broken down into three sons of geologic time. The __________ and __________ eons lasted about 4 billion years. The __________ eon includes the last half billion years.

Archaean; proterozoic; phanerozoic.

Atmospheric oxygen began to appear 2.7 billion years ago as a result of __________.

Prokaryotic photosynthesis.

__________ and __________ cellular respiration allowed prokaryotes to flourish.

Anaerobic; aerobic.

The evolution of __________, which uses O3 in harvesting energy from organic molecules, allowed their prokaryotes to flourish.

Cellular respiration.

The oldest fossils of single celled __________ are about 2.1 billion years ago.

Eukaryotes.

The common ancestor of all multicellular eukaryotes lived about _____ billion years ago.

1.5.

The origins of __________ and __________ organisms and the colonization of land are key events in life's history.

Single-celled; Multi-celled.

__________ diverged from other primates about 6-7 million years ago

Humans.

Our species, __________ originated about 195,000 years ago.

Homo sapiens.

Atmospheric oxygen began to appear 2.7 billion years ago as a result of __________.

Prokaryotic photosynthesis.

__________ and __________ cellular respiration allowed prokaryotes to flouish.

Anaerobic; aerobic.

The evolution of __________, which uses O2 in harvesting energy from organic molecules allowed other prokaryotes to flourish.

Cellular respiration.

The oldest fossils of single-celled called _______________ are about 2.1 billion years.

Eukaryotes.

The common ancestor of all multicellular eukaryotes lived with out income.

1.5.

The origins of __________ and __________ organisms and the colonization of land are key events in life's history.

Single-celled; multi-celled.

The most widespread and diverse land land animals are __________ (particularly insects, and spiders, and __________..

Anthropods; tetrapods.Tet

__________ are inevitable in a changing world and the fossil record shows that the vast majority of species that has ever lived no longer exist.

Extinctions.

The Permian and Cretaceous mass extinctions mark the ends of the __________ and ___________ eras.

Paleozoic; Mesozoic.

Addresses the interface of evolutionary biology and developmental biology and examines how slight genetic changes can produce major morphological difference.

Evo-devo.

A salamander that illustrates a phenomenon called __________, the retention in the adult of features that were juvenile in an ancestral species.

Paedomorphosis.

Paedomorphosis occurs in the _______________, which sexually mature adults retain gills and other larval features.

Axolotx salamander.

In the evolution of any complex structure, behavior, or biochemical pathway, each step must bring a _______________ to the organism possessing it and __________ the organism's fitness.

Selective advantage; increase.

__________ is the evolutionary history of a species or group of species.

Phylogeny.

__________ are similarities due to a shared ancestry, evolving from the same structure in a common ancestor.

Homologies.

Some similarities are due to similar adaptations favored by a common environment, a process called _____________________.

Convergent evolution.

A similarity due to convergent evolution is called a(n) __________.

Analogy.

Which evolutionary advance gave the gymnosperms an adaptive advantage at the time they were evolving?

Seed.

Bryophytes are small because

They lack vascular tissue.

During the B=Carboniferous period, forests consisting mainly of __________ and __________ produced vast quantities of organic matter, which was buried and later became coal.

Fruit and seedless plants.

__________ are vascularized plants that produced seeds but do not bear flowers. They are basically trees.

Gymnosperms.

Human survival literally depends on the produce from __________.

Angiosperms.

Which of these early terrestrial organisms is believed to have evolved vascular tissue?

Ferns

Humans use fungi as __________.

Food.

The closest algal relatives of land plants are __________.

Charophyceans.

Angiosperms are different from all other plants because only they have what?

Flowers.

Fungi uses __________ to reproduce.

Spores.

What is a fungus infection commonly found on the feet of humans?

Ringworm.

A fruit is a ripened __________.

Ovary.

There is evidence that both fungi and animals evolved from __________.

Protists.

__________ are radially symmetrical carnivores that use tentacles armed with batteries of stinging cells to capture prey.

Cnidarians.

Both humans and sea stars share features of __________ development.

Embryological.

__________, though tied to water for __________, include species that are, otherwise entirely terrestrial.

Amphibians; reproduction.

The __________ allows for reproduction and development within a structure that provides moisture, food, waste storage, and gas exchange.

Amniotic egg.

__________, also known as segmented worms, have a closed circulatory system.

Annelids.

__________ have jointed appendages and an exoskeleton that must be shed to permit growth.

Arthropods.

__________ exhibit two radial body forms, the polyp and the medusa, and use stinging cells to capture prey.

Cnidarians.

__________ (meaning"spiny skin") have a water vascular system that functions in locomotion, feeding, and gas exchange.

Echinoderms.

__________ are the simplest bilaterian animals and lack a body cavity.

Flatworms.

__________ have a body plan with three main parts; a visceral mass, a mantle, and a foot.

Molluscs.

__________ have a pseudocoelom and are the simplest animals that have a complete digestive tract.

Nematodes.

__________ are sessile animals that have specialized cell called amoebocytes and choanocytes.

Sponges.

The phrase "Cambrian explosion" refers to _________________________.

The rapid adaptive radiation that gave rise to most extant animal phyla.

Which animal phylum is most closely related to the phylum Chordata?

Echinodermata.

One body plan, called bilateral symmetry, represents a major branch point in animal evolution and can be described as

A body plan with only one way to split it into two equal halves-- right down the midline.

Consider the following list of animals: giant squid, earthworm, largemouth bass, snail, tapeworm, coral, and sea star. The two that belong to the same phylum are the __________ and the __________, and their phylum is __________.

Giant squid; snail; Mollusca.

Biology deals with many kinds of worms. Which choice includes three different phyla of "worms"?

Platyhelminthes, Annelida, Nematoda.

The majority of animal species are __________.

Insects.

A characteristic of cnidarians is ____________________.

Tentacles with stinging cells.

While on a biological expedition, you discover a new species with the following characteristics: has an exoskeleton, exhibits bilateral symmetry, and has jointed appendages. What phylum does this newly discovered organism belong to?

Arthropoda.

There are three major groups of mammals, categorized on the basis of their _______________.

Method of reproduction.

Which phylum includes animals that have the following characteristics: a dorsal, hollow nerve cord; a notochord; pharyngeal gill slits; and a post-anal tail?

Chordata.

Imagine you are a paleontologist. In a recent dig, you unearthed the following bones: jaw bone, vertebral column, and femur. Which phylum does the organism you unearthed belong to?

Chordata.

Most members of which class of chordates exhibit a mixture of aquatic and terrestrial adaptations?

Amphibia.

What are the two key features of members of the class Mammalia?

Hair and mammary glands.

Primates are distinguished from other mammals by _________________________.

Dexterous hands, nails, and good depth perception.

The evolution of humans included which of the following?

Increased brain size.

An organism is multicellular, ingests food, and undergoes a metamorphosis stage during its lifetime. What type of organism is it?

Animal.

Animals probably evolved from colonial protists. How do animals differ from these protist ancestors?

Animals have cells that are more specialized.

How are animals different from fungi?

Animals obtain food by ingestion, and fungi obtain food by absorption.

What percentage of animals are invertebrates?

95.

Unlike other animals, sponges _______________.

Lack true tissues.

Sponges feed by ____________________.

Filtering small particles from water.

Flatworms are the simplest animals with _______________.

Bilateral symmetry.

The __________ include the largest number of species.

Arthropods.

Members of the phylum Mollusca _________________________.

Are soft-bodied and usually covered by a shell i.e. oysters; clams.

Sea stars and sand dollars belong to a group of spiny marine animals called __________.

Echinoderms.

An animal has segments, bilateral symmetry, pharyngeal slits, a post-anal tail, and a notochord. It must be a member of the phylum __________.

Chordata.

A __________ is a chordate but not a vertebrate.

Lancelet.

The first vertebrates to colonize land were __________.

Amphibians.

The development that freed vertebrates from water for reproduction and allowed them to radiate into diverse terrestrial environments was the __________.

Amniotic egg.

All mammals have __________.

Mammary glands.

The kangaroo is an example of a(n) __________ mammal.

Marsupial.

Humans, apes, and monkeys are classified together as __________.

Anthropoids.

Humans are most closely related to __________.

Chimpanzees.

__________ arose very early in hominid evolution; _________ evolved more recently.

Upright posture; large brains.

Which human feature evolved most recently?

Enlarged brain.

What mode of nutrition distinguishes animals from fungi, both of which are heterotrophs.

Ingestion.

Why is animal evolution during the early Cambrian referred to as an "explosion"?

A great diversity of animals evolved in a relatively short time span.

A round pizza displays __________ symmetry, whereas a slice of pizza displays __________ symmetry.

Radial; bilateral.

Fluid-filled space separating the digestive tract from the outer body wall.

Body cavity.

If the body cavity is not completely lined by tissue derived from mesoderm, it is called a __________.

Pseudocoelom.

The type of body cavity humans and many other animals have, is completely lined by tissue derived from mesoderm.

Coelom.

The body plan of an annelid displays __________, meaning that the body is divided into a series of repeated regions.

Segmentation.

Which phylum is most closely related to the roundworms?

Arthropods.

What is the primary difference between your skeleton and a crab's skeleton?

Your skeleton is interior, whereas a crab has an exterior skeleton, (exoskeleton).

What are the four major groups of arthropods?

-Arachnids. -Crustaceans. -Millipedes and Centipedes. -Insects.

Which major arthropod group is mainly aquatic? Which is the most numerous?

Crustaceans; insects.

Unique to echinoderms is the _______________, a network of water-filled canals that circulate water throughout the echinoderm's body, facilitating gas exchange and waste disposal.

Water vascular system.

During our early embryonic development, what four features do we share with invertebrate chordates such as lancelets?

1. Dorsal, hollow nerve cord. 2. Notochord. 3. Pharyngeal slits. 4. Post-anal tail.

A shark has a __________ skeleton, whereas a tuna has a __________ skeleton.

Cartilaginous; bony.

Flexible skeleton made of cartilage.

Cartilaginous.

__________ have a lateral line system, a row of sensory organs running along each side of the body.

Sharks.

Sensitive to changes in water pressure, the _______________ enables a shark to detect minor vibrations caused by animals swimming in its neighborhood.

Lateral line system.

The skeletons of __________ are reinforced by calcium, having a lateral line system, a keen sense of smell, and excellent eyesight.

Bony fishes.

Protective flap on each side of bony fishes' heads; covers a chamber housing the gills, feathery external organs that extract oxygen from water.

Operculum.

bony fishes have an organ that helps keep them buoyant-- the _______________, a gas-filled sac.

Swim bladder.

Amphibians were the first __________, four-footed terrestrial vertebrates.

Tetrapods.

What is an amniotic egg?

A fluid-filled egg with a waterproof shell that encloses the developing embryo.

The evolution of __________ from an amphibian ancestor included many adaptations for living on land.

Amniotes.

Birds differ from other reptiles in their main source of body heat, with birds being __________ and other reptiles being __________.

Endotherms; ectotherms.

The duck-billed platypus and the echidna, or spiny anteater are the only existing species of __________, egg-laying mammals.

Monotremes.

__________ are also called placental mammals because their placentas provide a more intimate and longer-lasting association between the mother and her developing young than do marsupial placentas.

Eutherians.

Which hominin species was the first to walk upright? Which was the first to spread beyond Africa?

Australopithecus afarensis; Homo erectus.

Humans first evolved on which continent?

Africa.

Bilateral symmetry in the animal kingdom is best correlated with

Mobility and active predation and escape.

Reptiles are much more extensively adapted to life on land than amphibians because reptiles

Lay eggs that are enclosed in shells.

Fossils suggest that the first major trait distinguishing human primates from other primates was __________.

Bipedalism.

Which of the following types of animals is not included in the human ancestry?:

-Bird; bony fish; amphibian; primate.

Bird.

Put the following list of species in order, from the oldest to the most recent: Homo erectus, Australopithecus species, Homo habilis, Homo sapiens.

Australopithecus species, Homo habilis, Homo erectus, Homo sapiens.

Match each of the following animals to its phylum:

a. Human. 1. Echinodermata.

b. Leech. 2. Arthropoda.

c. Sea star. 3. Cnidaria.

d. Lobster. 4. Chordata.

e. Sea anemone. 5. Annelida.

Human-- Chordata.

Sea Star-- Echinodermata.

Leech-- Annelida.

Lobster-- Arthropoda.

Sea Anemone-- Cnidaria.