Animal Classification 3 (mylab and mastering)

Which of the following statements best describes the overall process of descent with modification?

A trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor.

Drag the labels to the table to indicate which characteristics each phylum has. Labels may be used more than once.

Arthropods a. yes b. yes no c. no Echinoderms yes d. yes e. yes no Chordates f. yes yes g. yes h. yes

Which two main clades branch from the most recent common ancestor of the eumetazoans?

Cnidaria and Bilateria

Can you identify the groups to which the examples or characteristics belong? Drag the example or characteristic to the appropriate bin.

Invertebrate Chordates: - lancelet Cartilaginous fishes: - stingray Bony fishes - external gills for extracting oxygen with a flap that covers and sweeps waster over them - trout Amphibians - a mix of terrestrial and aquatic adaptations - poison cane toad Reptiles - parakeet - boa constrictor - a hard-shelled egg and waterproof scales/feathers Mammals - kangaroo - hair and mammory glands

Drag the labels to the table to indicate which chordates (listed down the side) belong to each clade (listed across the top). Remember that a chordate may belong to more than one clade.

Lampreys a. yes no b. no no Ray-finned fishes yes c. yes no d. no Amphibians yes yes e. yes f. no Reptiles yes yes g. yes h. yes Mammals yes yes yes i. yes

Lancelets and tunicates are two groups of chordates. Classify each statement as applying to lancelets, tunicates, both lancelets and tunicates, or neither.

Lancelets: - all chordate characters present in adults - adults swim by the contraction of a series of muscles along the notochord - adults bury themselves into the sediment of the sea floor Tunicates: - in adults, water enters through one siphon and leaves through another - most chordate characters not present in adults - larvae swim using the notochord, but adults may be sessile Both: - adults feed with the aid of pharyngeal slits Neither: - adults swim using the vertebral column

Drag the labels onto this table about the skeletal features of tetrapod fossils. Use white labels for white targets, pink labels for pink targets, and blue labels for blue targets. Labels can be used once, more than once, or not at all.

Lungfish a. absent b. rays no limbs Panderichthys c. absent d. rays no limbs Tiktaalik e. present f. rays g. prop up in water Acanthostega present h. toes i. prop up in water Tetrapod j. present toes k. walk on land

Which of the following combinations of phylum and description is correct?

Platyhelminthes−−flatworms, gastrovascular cavity, no body cavity

Can you identify the animal phylum to which each example or characteristic belongs? Drag the example or characteristic to the appropriate bin.

Sponges - no body symmetry, central cavity Cnidarians - radial symmetry, gastrovascular cavity - jelly (jellyfish) Mollusks - giant clam Echinoderms - water vascular system, internal skeleton, and spiny body surface - sea star (starfish Flatworms - tapeworms Arthropods - body segments and har exoskeleton - fruit fly Chordates - contain tail, nerve cord, notochord, and pharyngeal slits - Homo sapiens

How did the great transition from fish to tetrapod occur?

The transition occurred gradually over time, so there are many intermediate forms

Why did Shubin and Daeschler search in the Canadian arctic for fossil evidence of the transition from fish to tetrapods?

They hypothesized that the transitional fossils were in sedimentary rocks older than 365 million years ago, when the first tetrapods appear in the fossil record. Shubin and Daeschler searched the Canadian arctic because it has rocks of the right age and type to hold transitional fossils.

What kind of habitat did tiktaalik live in?

Tiktaalik lived in a warm, freshwater swamp. When tiktaalik lived and became fossilized, its location was closer to Earth's equator, where warm, freshwater habitats were abundant. Over time, continental drift moved the pieces of Earth's crust (and all the fossils in the rocks above them) to different locations.

What is a transitional fossil?

Transitional fossils have features that are intermediate between ancestors and descendants. Species descend from other species. The fossil record includes fossils of animals with features that are intermediate, or transitional, between those of earlier and later species.

There are 7,000 species of echinoderms, all of which are marine, move slowly, and have a bumpy or spiky surface.

Water vascular system - A network of water-filled canals that allows the animal to exchange gases (O2 and CO2) with the environment. Endoskeleton - a calcium-hardened internal skeleton that provides structure. Mouth - Used for capturing and eating prey. Tube feet - extensions of the water-filled canals that allow for movement and capturing of prey.

Vertebrates and tunicates share

a notochord and a dorsal, hollow nerve cord.

Which of the following could be considered the most recent common ancestor of living tetrapods?

a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

Which of the following chordates is most likely to look the least like other chordates?

adult tunicate An adult tunicate does not have a notochord (or vertebrae), a nerve cord, or a post-anal tail. The only chordate feature it retains is pharyngeal slits.

The ___________________, a key adaptation for reptiles, has a waterproof shell that encloses the embryo and its life-support system

amniotic egg

Listed below are four adaptations of terrestrial vertebrates. Which choice is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle?

amniotic egg In contrast to the shell-less eggs of amphibians, amniotic eggs (of most reptiles and a few mammals) have shells that retain water and can be laid in a dry place.

A group of animals called ____________________ have several adaptations for living on land but must return to the water to breed.

amphibians

Most members of which of the following groups are most closely associated with a wet (or moist) environment?

amphibians Amphibians typically have water-permeable skin that does not easily-resist drying. Thus, amphibians tend to be found in moist environments.

The diagnostic feature of Chondrichthyes is __________.

an endoskeleton of cartilage The cartilaginous skeleton of sharks and their relatives are often impregnated with calcium.

A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Based on this description, it may be determined that the animal must be a(n) __________.

annelid The description matches the characteristics of annelids.

Jaws evolved __________.

by modification of the skeletal rods that previously supported the anterior pharyngeal slits According to a leading hypothesis, this marked a reduction in the number of pharyngeal slits and a change in the function of gills from feeding to respiration.

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

chordate

In contrast, _________________ push captured prey into their central cavity, where the prey are digested into components that can be absorbed by cells lining the cavity. This allows eating relatively _______________ organisms.

cnidarians; large

What is the evolutionary cause of such changes?

descent with modification

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

endoskeleton

A(n) _______________ is an organism that generates heat within its body; a(n) __________________ is an organism that must obtain heat from the environment.

endotherm; ectotherm

The water vascular system of echinoderms

functions in locomotion and feeding.

What are the two defining features of the class Mammalia?

hair and mammary glands These are the two characteristics unique to mammals.

Unlike eutherians, both monotremes and marsupials

have some embryonic development outside the uterus

What can you infer about its phylogeny? Place its class on the correct branch of the phylogenetic tree. Identify the key derived characters that distinguish this animal from invertebrate chordates.

https://slidetodoc.com/presentation_image/3167253a5718adf185d9a08a2ec17a06/image-22.jpg

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

A row of organs that are sensitive to changes in water pressure is called a _______________.

lateral line system

A fish that has muscular pectoral and pelvic fins supported by rod-shaped bones is known as a ________________.

lobe-fin

Choose the class to which this animal belongs. This animal is a vertebrate with hair.

mammalia

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

method of reproduction Monotremes are egg-laying mammals, marsupials are pouched mammals, and eutherians are placental mammals.

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

notochord

Movement of the ________________ allows some fish to breathe without swimming.

operculum

A fish that has a bony skeleton and thin, flexible supports in its fins is known as a _______________.

ray-finned fish

Adaptations that evolved in the group of animals called the _____________________ have allowed them to complete their life cycles entirely on land.

reptiles

Which of the following are thought to be most closely related to humans?

sea stars Humans and sea stars are deuterostomes.

Animals such as __________________ have a central body cavity, not a digestive tract.

sponges and cnidarians

In __________________, this central cavity is lined by cells that use phagocytosis to remove food particles from water drawn into the cavity. This allows eating relatively _________________ organisms.

sponges; small

The gas-filled sac found in many fishes is called a ________________.

swim bladder

A four-limbed, land-dwelling vertebrate is generally known as a(n) __________________.

tetrapod

Living vertebrates can be divided into two major clades. Select the appropriate pair.

the cyclostomes and the gnathostomes

In the phylogenetic tree shown, which of the following are shared ancestral characters for members of the turtle-leopard group?

vertebral column; four limbs

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

vertebrates

All of the following represent diagnostic features of chordates except for which one?

veterebrae Lancelets and tunicates are two subgroups of chordates that lack vertebrae.

Which evidence supports the hypothesis that four-limbed animals came from fish?

- DNA analysis shows that fish are tetrapods' closest relatives. - The fossil record shows more and more tetrapod-like fish before the appearance of tetrapods about 365 million years ago. - Both fish and four-limbed animals are vertebrates. - Fish and four-limbed animals have very similar embryos. Evidence from genetics, embryology, physiology, and the fossil record all support the hypothesis that tetrapods evolved from fish.

The phylogenetic tree shown here displays the major clades of chordates. Which statements about the phylogenetic tree are true?

- Organism (a) is a common ancestor of all chordates - Descendants of organism (d) have limbs with digits - Mammals and turtles are more closely related than are lungfishes and sharks - Birds and ray-finned fishes have a notocord and jaws - Rays and frogs have vertebrae

Why have we NOT found examples in the fossil record of every animal that ever lived on Earth?

- To become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock. - Many fossils remain buried. We can only find them when they are exposed by erosion or excavation. - To become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose. Incredibly few of the organisms that live in any particular time become fossils. Though the fossil record shows a remarkable diversity of organisms, they are likely only a fraction of those that lived in past environments.

Evolutionary reversals (character losses) are also common among living members of a vertebrate lineage and early members of the lineage. Choose examples that illustrate this observation.

- Whales and snakes lack legs. - Living birds lack teeth. - Most mammals lack shelled eggs.

Which of the following is a tetrapod?

- an amphibian - a bird - a mammal - a reptile Mammals, amphibians, reptiles and birds are all tetrapods. Their limbs are built with the "one bone, two bones, many bones, digits" arrangement Dr. Shubin describes in the film.

Living members of a vertebrate lineage can be very different from early members of the lineage. Choose examples that illustrate this observation.

- early reptiles with four legs and living birds with two legs - early reptiles with four legs and living snakes that lack legs

Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?

- interlocking ribs - flat head with eyes on top - a neck Tiktaalik had characteristics of both fish (scales, fins, and fin rays) and tetrapods (flat head, eyes on top, strong interlocking ribs, and a neck). These characteristics would have enabled it to survive both in and out of water, like amphibians and reptiles today.