Chapter 27 Bio 192

amniote

Member of a clade of tetrapods named for a key derived character, the amniotic egg, which contains specialized membranes, including the fluid

amphibian

Member of the tetrapod class Amphibia, including salamanders, frogs, and caecilians.

arthropod

A segmented, molting bilaterian animal with a hard exoskeleton and jointed appendages. Familiar examples include insects, spiders, millipedes, and crabs.

bilaterian

Member of a clade of animals with bilateral symmetry and three germ layers.

body plan

In multicellular eukaryotes, a set of morphological and developmental traits that are integrated into a functional whole the living organism.

Cambrian explosion

A relatively brief time in geologic history when many present day phyla of animals first appeared in the fossil record. This burst of evolutionary change occurred about 535 525 million years ago and saw the emergence of the first large, hardbodied animals.

chordate

Member of the phylum Chordata, animals that at some point during their development have a notochord a dorsal, hollow nerve cord; pharyngeal slits or clefts; and a muscular, post-anal tail

a dorsal, hollow nerve cord

invertebrate

An animal without a backbone. Invertebrates make up 95% of animal Species.

mammal

Member of the class Mammalia, amniotes that have hair and mammary glands (glands that produce milk).

reptile

Member of the clade of amniotes that includes tuataras, lizards and snakes, turtles, crocodilians, and birds.

tetrapod

Member of a vertebrate clade characterized by lines with digits. Tetrapods include mammals, amphibians, and birds and other reptiles.

tissues

An integrated group of cells with a common structure, function, or both.

vertebrate

A chordate animal with a backbone. Vertebrates include sharks and rays, ray finned fishes, coelacanths, lungfishes, amphibians, reptiles, and mammals.

Summarize evidence about the origin of animals and characterize the traits of early- diverging animal lineages.

Choanoglagellate were evidence of ancestors, the ediacaran soft bodied animals showed up. Sponges and cnidarians are the two group that diverged from other animals. Cnidarians are the true animals are are motile.

Identify major milestones in animal evolution that occurred during the Cambrian explosion.

More animals started to come out, predator prey relationships formed.

• Hox genes affected genes that facilitated evolution of new body forms

• Daing the origin of Bilaterians that have a complete digestive tract- declined diversity of edicarans

Differentiate between different types of animal “body plans,” and characterize major traits of invertebrate animals and chordates

Radial symmetry: mainly sessial (stagnent)

Bilateral: likely to move around because of CNS, have 3 Germ layers, have body cavities

Discuss the colonization of land by arthropods and tetrapods.

Arthropods colonized land earlier, while tetrapods evolved from aquatic vertebrate ancestors. Both groups developed adaptations for terrestrial movement, respiration, and protection against dehydration.

Describe adaptations for life on land found in the amniotes and characterize traits in present-day members of this group.

The defining characteristic of amniotes is the amniotic egg and its associated membranes, which allowed vertebrates to reproduce on land rather than relying on aquatic environments.

Fill in

1. Tissues

2. Bilateral symmetry, 3 Tissue layers

3. Skull and backbone

4. Jaws and bony skeleton

5. Limbs with digits

6. AMniotic egg