Mastering #4

The first animals evolved ________.

600 million years ago

The first animals evolved from ________.

Protists

Mollusks are more closely related to flatworms than to roundworms.

True

How do bony fish regulate buoyancy?

With an air-filled swim bladder

A population in ecology is defined as ________.

a group of organisms, all from the same species

Most of the prokaryotes known as ______ live in extreme environments, such as salty lakes.

archaea

Bacteria with rod-shaped cells connected end-to-end are called _________.

bacilli

Kingdom ______ consists of multicellular eukaryotes that produce their food by photosynthesis.

plantae

Genetically modified organisms that acquire genes from a different species are called ________ organisms.

transgenic

Binary fission produces __________.

two genetically identical bacterial cells Submit

For a species with a Type II curve, less than ____% of individuals survive for 50% of the maximum life span.

10

What is the difference between a community and an ecosystem?

A community includes interacting populations without their surrounding environment, while an ecosystem includes the surrounding environment. Submit

Why is it hard to classify protists? Because they differ in their complexity, some being unicellular, some being multicellular Because they come from such in such a wide variety of size and shape Because they differ in their nutrition and energy use All of the above are reasons why protists remain hard to classify

All of the above are reasons why protists remain hard to classify

Kingdom ________ consists of multicellular eukaryotes that obtain their food by ingesting (eating) other organisms.

Animalia

Serial repetition of segments is a defining characteristic of which worm phylum?

Annelids

What defines radial symmetry?

Any plane of symmetry passing through the center of the organism splits it into equal halves.

Which organisms are called extremophiles and flourish mostly in extreme conditions?

Archaea

Which worm phylum lacks body segmentation?

Both flatworms and roundworms

According to this graph, species that exhibit a Type III curve typically produce large numbers of offspring.

Cannot be determined from this graph

The echinoderms are most closely related to the ________.

Chordates

Which type of worm lacks a complete digestive tract?

Flatworms

Of those listed below, which category of classification is the most narrow?

Genus

What is represented on the x-axis of this graph?

Individuals' life spans as a percentage of the maximum life span for the species

What is the main difference between monotremes and eutherians?

Monotremes lay eggs, while eutherians give birth to live young.

What do sponges and cnidarians have in common? Mobility Symmetry Organization of cells into tissues None of the above are characteristics that sponges and cnidarians share

None of the above are characteristics that sponges and cnidarians share

For species with a Type III curve, most individuals reach the maximum life span.

Not supported

One of the features shared by all chordates is a(n)______, a flexible rod that runs along the top side of the back.

Notochord

Being a heterotroph means ________.

Obtaining your food by eating other organisms

What are the key characteristics of arthropods?

Segmented bodies, tough exoskeleton, and jointed appendages

Which specialized structures are unique to the cnidarians?

Stinging cells

In species that exhibit a Type II survivorship curve, individuals are no more likely to die at one stage of the life cycle than another.

Supported

At 50% of maximum life span, how does survivorship for a Type I curve compare to survivorship for a Type III curve?

Survivorship for a Type I curve is nearly 1,000 times as great as survivorship for a Type III curve.

According to this phylogenetic tree, which bear is most closely related to the American black bear?

The Asiatic black bear

Which of the following phyla is the most diverse and numerous of all animal phyla?

The arthropods

What do survivorship curves display?

The change that an individual will live to a particular age

Which of the following statement is correct regarding the phylogenetic tree above?

The polar bear and the brown bear are the most recently evolved species.

Which body form of the cnidarians is sessile?

The polyp

Three of the following statements are correct. Identify the statement that is not correct regarding genetically modified organisms. GM animals are not in our food supply. GM crops have been produced that are disease resistant. There are no risks associated with GM crops. GM crops have been produced with increased nutrition.

There are no risks associated with GM crops.

Which of the following best describes mollusks?

They are bilaterally symmetrical and have a soft body sometimes covered with a shell.

Why is a percentage scale used for the x-axis rather than actual ages?

This scale allows you to compare species with widely varying life spans on the same graph.

How did mitochondria and chloroplasts arise in eukaryotic cells?

Via endosymbiosis, where mitochondria and chloroplasts were independent prokaryotic organisms that were engulfed by a larger cell

_______ are the most diverse and widespread prokaryotes.

bacteria

Viruses that infect bacteria are called ________.

bacteriophages

The phylum _______ contains animals that share four specific anatomical features, including a hollow nerve cord and a tail.

chordate

Organisms with prokaryotic cells are separated into two _______, Bacteria and Archaea.

domains

All vertebrates have a(n) ________ , an internal system of bones (in your case, 206 bones).

endoskeleton

All organisms with eukaryotic cells are grouped in domain _______

eukarya

Kingdom ________ includes eukaryotic organisms that mostly decompose organic wastes and absorb nutrients into their cells.

fungi

A(n) ________ is an animal that lacks a backbone and may or may not have all of the chordate features.

invertebrate

A(n) _______ is an example of an animal that is a chordate but not a vertebrate.

lancelet

_______ are a diverse collection of mostly single-celled eukaryotes, which are sorted into several kingdoms to reflect their evolutionary relationships.

protists

A(n) ______ is an animal that has a backbone in addition to displaying the four features of all chordates.

vertebrate