New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Bio 3063, Week 3 tuesday

by: Joanne Saldanha

Bio 3063, Week 3 tuesday PCB 3063

Marketplace > University of Central Florida > Biology > PCB 3063 > Bio 3063 Week 3 tuesday
Joanne Saldanha
University of Central Florida

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Sex and Extension of Mendelian Genetics
Walter Sotero
Class Notes
25 ?




Popular in Genetics

Popular in Biology

This 8 page Class Notes was uploaded by Joanne Saldanha on Monday September 5, 2016. The Class Notes belongs to PCB 3063 at University of Central Florida taught by Walter Sotero in Fall 2016. Since its upload, it has received 3 views. For similar materials see Genetics in Biology at University of Central Florida.

Similar to PCB 3063 at University of Central Florida


Reviews for Bio 3063, Week 3 tuesday


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 09/05/16
Turner Syndrome: Turner syndrome: 45, X Sexual phenotype depends on the presence of sex chromosomes. In drosophila, the number of X  chromosomes matter. Thus, a XXY would be a female. But in humans, it would be a male.  XYY condition: Non­ disjunction of Y chromosome in Anaphase II. These individuals are  usually very tall and exhibit antisocial behavior. Maleness is the presence of a Y chromosome; femaleness is due to the presence of X  chromosome.  On the X chromosome, there are only a small amount of genes that express the female genotype.  Most of the genes code for similar functions.  The X chromosome is a bright spot in the nucleus. This is the barr body that has all the inactive  genes. This is called barr bodies. Result is dosage composition.  In general, only one X chromosome is active. The number of barr bodies is total X chromosomes minus 1.  So why klinefelter or turner? i) Inactivation of X chromosome and formation of barr body doesn’t happen right away during embryonic development. This affects the initial phenotype of the child. All the descendants of the cell in stage 2 will inactivate the same X chromosome.  ii) X chromosome inactivation is not 100%. This explains phenotypic expression of sex related disorders.  This means females are mosaics for all X linked genes for which they are heterozygous.  Males cannot be homozygous. Males are hemizygous for X linked genes.  Tortoise shell cat: There is a locus in cats that controls color. In the patches of skin where the orange allele has been inactivated ,that patch of skin is black and vice versa. This is a mosaic. •Tortoiseshell: patches of orange and black (X­linked)  •Calico: tortoiseshell cats with white spots (due to the expression of a separate spotting gene) in addition to the o Patches of orange and black. o Normal males do not exhibit these patterns because they are hemizygous: XOY (orange) or XBY (black). •normal XY males always have either a single solid color or patches of one color plus white spots •male tortoiseshell cats can happen when they are XXY (klinefelter in humans)  Tortoise shell and calico cats with two colors are generally females. Anhidrotic ectodermal dysplasia  X-linked disorder •males lack sweat glands  •the skins of heterozygous females are mosaics (in patches) The human Y chromosome Regions:   pseudo-autosomal regions (PAR, ~5% of the chromosome): share DNA sequence homology with regions of the X chromosome (the pairing of X and Y during meiosis is necessary for X-Y segregation)  male-specific region of Y (MSY): the remaining 95% . Any locus or gene in this region will be passed from father to son.  sex-determining region of Y (SRY): the gene that controls male sexual development-  testis-determining factor (TDF, the product of the SRY gene): a transcription factor (DNA-binding protein) that initiates male sexual development. X­linked inheritance •normal females have two X chromosomes, so they may be either homozygous or heterozygous  for any X locus •normal males have only one X chromosome, so they are hemizygous for all X­linked loci •normal males always express the phenotypes associated with X­linked alleles Thomas H. Morgan analysis of the white locus (1910).  Very easy to grow, large sample size, easily detectable mutation and short life span.  Alleles: +: red eye or brick red (wild­type)  w: white eye (null recessive mutant)­ [no pigmentation is recessive] null allele­ recessive allele or allele that doesn’t code for a functional product. Case A: All white eyed flies are males. For red eyed individuals, females outnumber males, 2:1. This is  not Mendelian genetics.  Case B: Here again the same results were obtained. Thus Morgan concluded that the gene for eye color is on the X chromosomes. Case A: In the P1 generation, x chromosome is I. + + w P1: I I x I ( red eyed­ female) (white eyed male) P1 gametes:     I w I and  + w + F1:  I I I Red eyed female Red eyed male + w + F1 gametes:  I and  I I and  F2 :  + I  +I +I I +I red,  female male  w + w I I I I  red,  White,  female male Case B: Reciprocal cross P1: I Iw x +I ( white eyed­ female) (red eyed male) w + P1 gametes:     I         I and  + w w F1:  I I I Red eyed female White eyed male F1 gametes:  I and  Iw wI and  F2 :  wI  +I +I I +I red,  red,  female male w w w w I I I I  white,  White,  female male Ability of chromatic vision is the responsibilities of 3 pigments in the retina­ blue, green and  yellow­orange The X chromosomes code for these. Normal chromatic vision would be able to see the number 8  on a green background.  X linked color blindness see a 3 on a green background. X linked recessive traits are commonly  expressed in guys because they only have one X chromosome.  How do barr bodies factor in? It would depend. If the retina cells have inactivated the color  blindness allele and only the color allele remains, all colors will be visible and vice versa. A  mosaic effect can also occur here.  More on notations: For a female with normal color vision could be CC  or Cc while colorblind can be cc. Males can  be C or c or ever CY or cY.  C is for normal color vision.  c is for color blindness allele. Is it possible for two individuals with dominant traits to have children with recessive traits?  Yes. Both parents have to be heterozygous. 25% would have recessive traits.  Extensions of Mendelian Genetics Alleles are different forms of a gene (e.g. G and g). •if an individual has two variations of a gene, the two genes are said to be allelic (Gg) •if an individual has two copies of the same form of a gene, these two genes are non­allelic  (because they are identical genes) (GG or gg) •for two genes to be considered alleles they must map to the same locus (same position) on  homologous chromosomes Wild type refers to the phenotype of the most common form of a species as it occurs in nature. Null allele: a mutant allele with the effect of either the absence of gene product or the absence of  gene product function. Most null alleles behave as recessive.


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Kyle Maynard Purdue

"When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the I made $280 on my first study guide!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.