Study Guides (238,161)
Canada (114,963)
Biology (1,227)
BIO3102 (98)
All (96)

silurian and denovian.docx

5 Pages
Unlock Document

University of Ottawa

Agnatha Jawless fishes Example Lamprey Mouth is constantly open and is an ectoparasite on bodies of larger fishteeth are used to attach fish and eat them alive can detach and attach at another location Lampreys will swim out of oceans into fresh water creeks to lay their eggs and once born the lamprey will return to the oceansbut salmon do this too The lampreys have destroyed the commercial fishing of salmon in the great lakesAlternation of generations Green algae life cycleThe algae do not spend a long lime as large vegetative statehaploid filaments are capable of differentiating and creating gametesandfilaments not male and female yet The two filaments can fuse to create a 2n zygote which undergoes meiosis to create spores which are haploid The plant can create gametes that are haploid or just regenerate asexually The diploid stage is shortlived Division of labour In first plants the gametophyte is very dominant but as you move further along the gametophyte stage becomes contained in sporophyte stageThe archegonia will be housed in sporophyte plant the sperm will be packaged in pollen There needs to be a mechanism to bring them together without swimming Antheridia SpermThe male sex organ of algae mosses ferns fungi and other nonflowering plants Archegonia EggThe female sex organ in mosses liverworts ferns and most conifers Arthropoda Bony fish At the end of the denovian the bony fish appear their bones are mineralizedmodifications of the body structure which makes the fish even more effective the fins are now anchored to the central body structure which allows fish to make very agile movementsThe bony fish can use their structure to hover and hide making them very effectivethey can also stop dead which required a new mechanism to aerate the gills Cartilagenous fish Skeletal structure is composed of cartilage example is the sharkthe jaw is present and there is an extension of the vertebral column as the tail which is used to move the shark There are fins on either side which are used to stabilize movementthis allows shark to feed as it movesThe skeleton of catilagenous fish is not mineralized and the appendages are not anchored to the skeleton mostly anchored by muscles of the body wall this means that the pectoral and pelvic fins are not very agileSharks have gills to carry out gas exchange but they must be in constant motion to force water over the finsAquatic animals are denser than water so they must always be expending energy on combating sinking In order to overcome this they secrete oils into their tissues to make them less dense
More Less

Related notes for BIO3102

Log In


Don't have an account?

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.