These notes are a 3-page summary of GTS161 study unit 3. They provide a detailed but concise overview of the lecture notes with colour images to aid understanding. They were written by a student who obtained a distinction in the module.
Theme 3
Sex
•
Hermaphrodi.sm - both sexes in 2. XX-XO determina.on:
same organism § Females (XX) - soma.c cells
• Monoecious - both male and have 2x autosome sets and
female reproduc.ve structures in 2X / haploid cells have one
same organism autosome set and 1X
• Diecious - either male or female chromosome
reproduc.ve structures in one § Males (XO) - soma.c cells
organism have two sets autosomes and
§ Chromosomal, 1X chromosome / sperm
environmental or genic sex have one set autosomes and
determina.on either 1X or no sex
Chromosomal sex determina.on chromosome
• Determined by genes on 3. ZZ - ZW sex determina.on
chromosomes § Females (ZW) - soma.c cells
• sex chromosomes - chromosomes have two sets of autosomes
which differ in number and/or and 1Z or 1W / eggs have one
morphology between males and set of autosomes and 1Z or
females 1W
• Autosomes - the same in males § Males (ZZ) - soma.c cells
and females have two sets of autosomes
• Homogame.c sex - sex that and 2Z / sperm have one set
produces gametes that are all the of autosomes and 1Z
same with respect to the sex Genic sex determina.on
chromosomes • NO sex chromosomes
• Heterogame.c sex - sex that • Genes on autosomes determine
produces two different types of sex
gametes with respect to the sex Environmental sex determina.on
chromosomes • Environmental factors determine
• SRY gene on Y = maleness sex
1. XX-XY determina.on: Drosophila melanogaster
§ Female (XX) - soma.c cells • Sex predicted by X:A ra.o (A -
have two sets of autosomes haploid sets of autosomes)
+ 2X chromosomes / • Y does not determine sex but plays
Haploid eggs - one set if a role in male fer.lity
autosomes and 1X
§ Males (XY) - soma.c cells
have two autosomes sets
and 1X / sperm have one
autosome set and 1X or 1Y
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller jessicagarnettinc. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
