Class Notes (809,569)
Canada (493,754)
Biology (6,677)
Biology 1001A (1,723)
Dr.Mike (47)
Lecture 16

Lecture 16.docx

4 Pages
Unlock Document

Western University
Biology 1001A

Lecture 16  Cnemidophorus uniparens: born female, stay female their whole lives, they reproduce asexually  Sex as recombination  o recombination -> genetic diversity o  generate new combination, main genetic diversity  crossing over, independent assortment  offspring distinct from either parent and (usually) each other  Sex is recombination  Sex =/= reproduction  o reproduction can happen without sex o binary fission: no recombination, asexually reproduction, give rise to two identical offspring o "Sex" without reproduction, exchange genetic material, but do not produce offspring o Quaking aspen colony: facultatively sexualf o  trees can reproduce sexually or asexually, (sexual -> flowers) o Amazon molly: obligately asexual o  cannot reproduce sexually, only asexual  Sexually reproducing organisms may be dioecious or monoecious  o Dioecious: two house holds, a male and a female (either male or female, can't be both) o Monoecious: hermaphrodite, individual has both male and female reproductive parts  Sequential monoecy (sex change)  o change sex some point in their life o common in coral reef fishes o Bluestreak wrasse: female to male o Clownfish: male to female  Size-advantage model of sex change  o males can be small size o female needs to be bigger in size because they need to lay eggs o Protandry: some species they start off as males, as they grow up, they become bigger, they becomes female so that they can lay more eggs  Distribution of sex  o First life forms almost certainly reproduced asexually o  most things, except plants and animals, reproduce mostly asexually  But among animals...  o marked in green is asexual, all the red tips are the organism reproduce sexually o most animals reproduce sexually  Why reproduce sexually?  o good reasons "not" to... o  cost of mating   need to look for a mate  compete for a mate
More Less

Related notes for Biology 1001A

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.