AP Bio Ch 34
Monotremes reproduction
egg-laying
Amnion
the amnion protects the embryo in a fluid filled cavity that cushions against mechanical shock
How do adult frogs breathe? (two ways)
-Gas exchange over skin -Bring in air through nostrils
Make a list of at least five traits of mammals, including the two in the concept heading. Put an asterisk (*) next to the traits unique to mammals
-hair -produce milk -subcutaneous fat -kidney -endothermic
Read the second paragraph about reptiles carefully, and then make a list of five characteristics of reptiles.
1) scales that contain the protein keratin 2) lay shelled eggs on land 3) internal fertilization 4) ectothermic 5) leathery skin
What are four avian adaptations for flight?
1) wings and feathers 2) lack urinary bladder 3) porous bones 4) gonads shrink during non-mating season
One of the important characteristics is a notochord. What is a notochord?
a longitudinal, flexible rod located between the digestive tube and the nerve cord. provides skeletal support to chordates
What is an amniotic egg? How has it enabled animals to occupy a wider range of terrestrial habitats than amphibians can?
an egg that has specialized membranes that function in protection, nourishment, and gas exchange. it allowed the embryos to occupy land in a fluid filled sac which eliminated the need for water
Important features of alligators and crocodiles
aquatic habitats, upturned nostrils
Vertebrates are not the only chordates. The lancet displays a number of chordate characteristics, and the ancestral chordate may have resembled a lancet. Describe a lancet.
blade-like shpae; larvae have notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. adults can reach 6 cm and retain many key chordate features
What does the class name Amphibia mean?
both ways of life
The "fishes" with a bone skeleton are aquatic Osteichthyes. How do they breathe?
by drawing water over their gills
What does the name Chondrichthyes mean? What material makes up their skeleton?
cartilage fish; cartilage
We are vertebrates. What phylum do we belong to?
chordata
Yolk sac
contains yolk and stockpile of nutrition
Dorsal hollow nerve cord
develops from ectoderm and develops into spinal cord and brain
Marsupials reproduction
develops in marsupium
Eutherians reproduction
develops in uterus
Allantois
disposal sac for certain metabolic wastes produced by the embryo
What other phylum might be considered our close relatives? Why?
echinodermata; both are deuterostome development
Chordates are the first group to show a dorsal nerve cord. Which embryonic layer forms the nerve cord?
ectoderm
Fertilization in amphibians is ______________________. The eggs lack a shell, and mortality is very high.
external
As a human, you are in the class Mammalia and the order Primates. What features are unique to primates only?
flat nails, large brain, flat face, opposable thumbs
Important features of birds
flight, feathers
What does tetrapod mean?
four feet
Important features of lizards
four limbs, external ears, moveable eyelids
For us, as vertebrates, what remains of the notochord?
gelatinous disks sandwiched between vertebrae
Pharyngeal gill slits develop into what structures in the fishes? What is their function
gills; gas exchange
Eutherians example
humans
What is the oldest lineage of vertebrates? ___________________ They are jawless parasitic fish with a skeleton made of ___________________________. Look at the mouth! Lampreys have invaded the Great Lakes and damaged the fishing industry there.
lampreys; cartilage
Notochord
longitudinal, flexible rod between the digestive tube and nerve cord
Fishes, amphibians, and reptiles are ectothermic. What does this mean?
means they use external sources such as the sun to regulate body temperature
What factors tie amphibians to a life near water?
need to keep skin moist and lay eggs in water
Important features of turtles
no holes in skull behind eye socket, box-like shell, terrestrial and marine habitats
Important features of snakes
no legs or arms, loosely articulated jaws and chemical sensors. lack eardrums
Pharyngeal slits
one of the slits that form from pharyngeal clefts and open into the pharynx, later developing into gill slits in many vertebrates
Marsupials example
opossum, kangaroo, koala
In tetrapods, what do the gill slits become?
parts of ear and other structures in head and neck
Monotremes example
platypus and echidna
What groups have an amniote egg?
reptiles and mammals
What animals are in the class Amphibia?
salamanders, frogs, caecilians
What is the body covering of a reptile? How does this enable it to live a more terrestrial life?
scales; scales prevent animals skin from dessication and abrasion
What animals are in the clade Chondrichthyes?
sharks, rays, and their relatives
Gnatho- means "jaw," and -stome means "mouth." This group includes the sharks, fishes, amphibians, and reptiles. From what structure is it believed that jaws evolved?
skeletal rods that supported anterior pharyngeal gill slits
Why do sharks have to swim continuously?
so they don't sink, and ensuring that water flows in through the mouth and out through gills ensuring gas exchange
Post anal tail
tail that extends posterior to the anus
Chorion
the chorion and the membrane of the allantois exchange gases between the embryo and the air
What is internal fertilization? How does this enable reptiles to reproduce on land?
the unions of sperm and egg inside the female body. enables reptiles to reproduce on land because typically species who have external fertilization need to release their sperm into water in order to reach the female
Birds are in the reptile clade. Which extinct group included their closest relatives?
theropods
What is the function of a swim bladder?
to maintain buoyancy equal to the surrounding water
What animals are in the reptile clade?
tuataras, lizards, snakes, turtles, crocodilians, and birds
Frogs have a life cycle with an aquatic larval stage, the tadpole. How do tadpoles breathe?
using gills