Class Notes (837,548)
Canada (510,312)
Biology (Sci) (2,472)
BIOL 111 (283)

Reptiles and Excretory System

3 Pages
Unlock Document

Biology (Sci)
BIOL 111
Irene Gregory- Eaves

08/11/11 Reptiles: Many reptiles are endangered due to human activities: - over harvesting - habitat manipulation Birds and mammals have two separate circuits: Reptiles (not including birds): - Intermediary with ventricle that’s somewhat separated and 2 atria - Some reptiles can shunt blood directly to aorta underwater Reptiles: - Terrestrial - More efficient heart, breathe only through lungs - Most conserve water w/ water proof skin and scales made of keratin - Shedding of skin happens in some reptile controlled by hormones - Produce nitrogenous waste to conserve water - Reproduce on land = internal fertilization and amniotic egg Non-avian reptiles: - 6000 species - Most terrestrial - Carnivorous, omnivorous, herbivorous - Dry skin, scales - First amniotes: arose in carboniferous Amniotic egg = egg surrounded by extra embryonic membranes: perhaps with external shall - Shell: leathery/brittle (CaCO3) - Impermeable to water - Permeable to gases - Not present in therian mammals - Embryo surrounded amnion for protection - Yolk sac produced by embryo - Allanntois: place for storage of waste and gas exchange - Chorion for gas exchange and water conservation - All surrounded by albumen Consequences of terrestrial egg: - internal fertilization must occur: - sperm cannot penetrate egg shell, shell and albumen are added to the fertilized egg after fertilization - must have non toxic nitrogenous wastes = uric acid Excretory system: 08/11/11 - control volume concentration and composition of extra-cellular fluids and excrete wastes Osmoconformers = organisms whose extracellular fluid is equilibrated with the environment - Limits to the ability of the organism to osmoconform: too salty denatures proteins - Too dilute can’t retain min amount of nutrients and salts Osmoregulators = organisms whose extracellular fluid is held at a concentration different from the envionment: - In tadpole: hypertonic - In marine fish: hypotonic Nitrogenous wastes: ammonia, urea-polar, uric acid-non polar 1. Ammonia: water soluble, but toxic Converted into urea/uric acid Produced by ray finned fish, invertebrate and larval
More Less

Related notes for BIOL 111

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.