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

Genetics Week Five

by: Jayda Abrams

Genetics Week Five BIO310

Jayda Abrams
Virginia Commonwealth University
GPA 3.52

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

These notes cover the last bit of information from chapter 4, that will appear on exam 1 on Wednesday (Sept 28th)!
Dr. Wu
Class Notes
genes, Genetics, Biology
25 ?




Popular in Genetics

Popular in BIO

This 6 page Class Notes was uploaded by Jayda Abrams on Monday September 26, 2016. The Class Notes belongs to BIO310 at Virginia Commonwealth University taught by Dr. Wu in Fall 2016. Since its upload, it has received 18 views. For similar materials see Genetics in BIO at Virginia Commonwealth University.

Similar to BIO310 at Virginia Commonwealth University


Reviews for Genetics Week Five


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: 09/26/16
Genetics Week Five Notes 9/26/2016 Information from the Power Point = Red Verbal information = Purple Chapter 4 Continued 4.9 Complementation Analysis Complementation analysis is used to see if things complement each other. Any trait may be controlled with two separate genes to give one look/phenotype. Complementation analysis  Screens number of individual mutations resulting in same phenotype  Can predict total number of genes determining a trait Complementation group- All mutations present in any single gene ***Figure 4-11*** 4.10 Expression of a Single Gene Gene- Pieces of DNA.  How long is it? – Length depends on the gene, different genes have different lengths The test/ analysis is to see if the phenotype is controlled by one gene or many. Pleiotropy- Expression of single gene has multiple phenotypic effects. (One gene has multiple effects. Example: A disease causing stomach pain and muscle pain do not have the same phenotype) Example: Porphyria variegata – Autosomal disorder – Toxic buildup of porphyrins in body – Numerous phenotypic effects  Abdominal pain  Muscular weakness  Vision issues Example: Marfan syndrome – Single autosomal dominant mutation in gene that encodes protein fibrillin results in multiple phenotypic effects 4.11 X Linkage Is a gene on an X chromosome or not? The sex of the male or the female does not matter! The sex of plants and animals are determined by X and Y chromosomes.  Example: Drosophila and humans – Males: XY – Females: XX The X chromosomes contains genes that effect phenotype. The Y chromosome only contains genetic information that determines if something is male or not. Non Reciprocal- Cannot switch the sex and get the same results. Males only need one recessive gene to have a mutation but females need two. This is called X- Linked genetics. Colorblindness- Colorblindness is due to the X-linked recessive allele b, while the X-linked dominant allele B leads to full color vision. Colorblindness in humans is on the X chromosomes. What happens when a female is colorblind?- The male offspring will be colorblind. Female offspring will not. Why? Males must carry one X chromosome to be colorblind and it is automatically passed down from mom because both of her X chromosomes have the colorblindness gene. X-linkage - Genes present on X chromosome exhibit patterns of inheritance however they are different from autosomal genes. Y chromosome- Relatively inert genetically, Male-specific genes found on human Y chromosomes, and lacks copies of genes found on X chromosomes. Some X linked traits include: Fabry’s Diseases, Hemophilia A, Hemophilia B, Ichthyosis and muscular dystrophy. Lethal X-linked recessive disorders – Observed only in males, not in females – Females can only be heterozygous carriers who do not develop the disorders Example: Duchenne muscular dystrophy – Onset prior to age 6 – Lethal around age 20 – Occurs only in males, not in females 4.12 Sex Limited and Sex Influenced Traits “Not everything is expressed. We do not see males with breast and females with mustaches even though we all have the same genes. The genes that are expressed are dependent on the sex. This occurs in other animals like chickens and changes how they look. A phenotype is limited to a sex.” Balding in men occurs more often than bolding than women. This is because balding is sex limited. Women will only show balding if they are homozygote dominant  Allele B behaves dominant in males and recessive in females. In BB genotype in females, phenotype is less pronounced. 4.13 Genetic Background and The Environment Phenotypic expression of trait – Influenced by environment and organisms exist in diverse environmental conditions – Influenced by genotype  Gene products function within cell in various ways Genetic background: Position effect – Physical location of gene influences expression – Translocation or inversion events modify expression – Gene relocated to condensed or genetically inert chromosome (heterochromatin) – Depends on the gene Temperatures can effect which genes are expressed. Temperature is useful when studying bacteria viruses. Dr. Wu’s research found that replication could occur at room temperature at (30˚C), however when it was raised to 40˚C, everything shut down. Nutrition can also affect how genes are expressed: Nutritional mutations – Prevent synthesis of nutrient molecules in microbes – Auxotrophs (microbe) – Phenotype expressed or not depending upon diet Example: People with obesity have the same genes, but they are impacted differently due to their nutrition. Henylketonuria – Loss of enzyme to metabolize amino acid phenylalanine – Severe problems unless low-Phe diet Galactosemia- Cannot metabolize galactose Lactose intolerance- Cannot metabolize lactose Onset of Genetic Expression Tay-Sachs disease Lesch-Nyhan syndrome  Inherited autosomal recessive  Inherited X-linked recessive  Lethal lipid-metabolism disease  Purine salvage enzyme defect (HPRTase) (hexosaminidase A)  Normal for about 6 months  Baby normal for a few months, dies by  X linked recessive disease characterized age 3 by abnormal nuc acid metabolism, leading to the accumulation of uric acid in blood and tissues, mr, palsy,self mutilation of the lips and fingers. Duchene muscular dystrophy (DMD) Huntington disease  X-linked recessive disorder  Variable age of onset in humans  Diagnosis at 3–5 years old, fatal by  Autosomal dominant disorder age 20  Affects frontal lobes of cerebral cortex  X linked disorder related to muscle  Progressive cell death – brain wasting deterioration  Age range 30–50 years old Genetic anticipation- Genetic disease has earlier onset and increased severity with each succeeding generation Example: Myotonic dystrophy (DM1) – Adult muscular dystrophy – Autosomal dominant – Increased severity and earlier onset with successive generations of inheritance Genomic (parental) imprinting Sometimes it matters if the same gene comes from mom or dad. – Selective gene silencing impacts phenotypic expression – Silencing depends on parental origin of genes – Silencing occurs in early development – Regions of chromosome imprinted on one homolog but not the other Imprint- genetic phenotype result of DNA modification and not a mutation. The CT from mom and the CT from dad are not the same. Imprints are modifications! What type of modification? The addition of a methyl. Imprint will then be inherited by the next generation. Epigenetic changes- Modifications that will change genetics because of imprints and not because of mutation. With an epigenetic change there is no change in the sequence and the only difference is the addition of the methyl. With a mutation there is a physical change in the base pairs. Silencing impacts phenotypic expression but it doesn’t change the gene. If you have cytosine you are subject to epigenetic changes. This change does not guarantee that the gene will be expressed. Genomic imprinting is an epigenetic process that involves methylation and histone modifications. Histones:  Histone binds DNA together and makes it look like a chromosome.  Histones bind DNA and make chromatin.  Histones are proteins and sugars are subject to modification (ex: glycoprotein) Histone modification- Adds different sugar groups. The binding of DNA will be tighter or looser. Which is better? Looser. If it is too tight expression can no occur and expression occurs best when everything is relaxed. This is a type of epigenetic change. DNA methylation – Involved in mechanism of imprinting and epigenetic effects – Methyl groups (CH )3added to 5 carbon – High levels of methylation inhibit gene activity – Active genes are undermethylated – Demethylation- if a gene is not methylated and doesn’t get expressed. Something is being blocked. DNA sequencing only gives information about DNA and does not give information about epigenetics.


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

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."

Amaris Trozzo George Washington University

"I made $350 in just two days after posting my first study guide."

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

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.