Unit 9- Chapters 25 and 26 Flashcards
Vocabulary and Key Ideas
the phylum chordata contains…
…all vertebrates and some invertebrates
all vertebrates share…
…common features
fossil evidence sheds light…
…on the orgins of vertebrates
chordates
share 4 features at some stage of their development
1) notocord
2) hollow nerve cord
3) pharyngeal slits
4) tail
notocord
a flexible skeletal support rod embedded in the animal’s back
endoskeleton
an internal skeleton built of bone or cartilage
fiash are vertebrates with…
…gills and paired fins
jaws evolved from…
…gill supports
only ___ groups of jawed fish still exist
2
gill
large sheets of thin frilly tissue filled with capillaries that take in dissolved oxygen from the water and release carbon dioxide
countercurrent flow
the opposite movement of water against the flow of blood in the fish’s gills
lateral line
a series of shallow canals on the sides of the fish made up of cells that are sensitive to small changes in water movement
operculum
covers the gills of all bony fish in a chamber covered by a protective plate
ray-fined fish have…
…a fan of bones in their fins
lobe-finned fish have…
…paired rounded fins supported by a single bone
ray-fin
fins that are supported by a fan-shaped array of bones
swim bladder
modified lungs that act as a buoyancy organ
lobe-fin
paired pectoral and pelvic fins that are round in shape
amphibians were the first animals with…
…four limbs
amphibians retuen to the water to…
…reproduce
modern amphibians can be divided into…
…3 groups
tetrapod
a vertebrate that has four limbs
amphibians
animals that can live both on land and in water
tadpole
aquatic larvae of frogs
amniotes can…
…retain moisture
amniotes do not need to…
…return to water to reproduce
amniote
a vertebrate tha has a thin, tough, membranous sace that encloses the embryo of fetus
keratin
a protein that binds to lipids inside the cell, forming a hydrophobic-or water repellent- layer that keeps the water inside the animal from reaching the skin
amniotic egg
an almost completely waterproof container that keeps the embryo from drying out as it develops
placenta
a membranous organ that develops in female mammals during pregnancy
amniote embryos develop in a…
…fluid-filled sac
___ and ___ differ among amniotes
anatomy and circulation
amniotes can be…
…ectothermic or endothermic
pulmonary cicuit
moves oxygen-poor blood from the heart to the lungs, and oxygen-rich blood back to the heart
systemic circuit
moves oxygen-rich blood from the heart to the rest of the body
ectotherm
organisms whose body temperatures are determined by their surrounding environment
endotherms
organisms that use their own metabolic heat to keep their tissues warm
reptiles are a diverse group of…
…amniotes
reptiles have been evolving for…
…millions of years
there are four modern groups of…
…reptiles
reptile
ectotherms that are covered with dry scales or plates on reproduce by laying amniotic eggs covered with a tough outer shell
oviparous
reptiles deposit their eggs into an external nest, and the eggs develop completely independent of the adult reptile
viviparous
reptiles hold the eggs inside their body through the duration of development and give birth to live offspring
birds evolved from…
…theropod dinosaurs
a bird’s body is specialized for…
…flight
birds have spread to many…
…ecological niches
airfoil
a curved surface that is curved down on the top (convex) and curved up on the bottom (concave)
sternum
same as breastbone
where the chest muscles attach along with arms
air sacs
in a bird body
connect to lungs
all mammals share several…
…common characteristics
modern mammals are divided into…
…three main groups
mammal
active, large-brained, endothermic animals with complex social, feeding, and reproductive behaviors
mammary gland
specialized glands tha produce milk
monotremes
mammals that lay eggs
marsupials
mammals that give birth to immature, under-developed live young that grow to maturity inside a marsupium, or pouch
eutherian
give birth to live young that have completed fetal development
