DNA

Claire 11/29/10

AZT- has a shape similar to T nucleotide in DNA and binds to the viral enzyme instead of T. Therefor, it blocks spread of HIV virus

Griffith- found "Transforming Factor"-killed harmful bacteria with heat, mixed with living cells of nonharmful bacteria, nonharmful bacteria became harmful. "Transforming Factor" was inherited by originally unharmful bacteria(which changed)

Hershey and Chase- DNA of a virus that is injected into host cells reproduces new viruses.

Franklin (& Wilkins)- Found helical shape (spins around itself) of DNA with x-ray crystallography

Watson and Crick- model of DNA, base pairing(what bonds with what), double helix structure

Earn Nobel Prize with Wilkins in 1962--Franklin died and was not included because they didn't want to give to this award to a female

Structure

Double Helix

nucleotide=1 sugar, 1 phosphate, 1 base

nucleotide=monomer

DNA=polymer

nucletides change to DNA through d

ehydration synthesis

Nucleic acid-"polynucleotide"

4 Nucleotides(bases): A=Adenine C=Cytosine T=Thymine G=Guanine

G bonds with C

A bonds with T

form hydrogen bonds with each other

DNA has three rings across, A and G have 2 rings and C and T have one. A and G can't bond because there would then be 4 rings across

T and C=pyrimidines(single ring)

A and G=purines(double ring)

N bases protrude from sugar

sugar-phosphate backbone

sugar=5 carbon ring=deoxyribose(missing oxygen atom)

1 nucleotide= nitrogen base, sugar, phosphate

nucleotides joined by covalent bonds between sugar and phosphate

Chargaff- in DNA, amount of A=amount of T, amount of G=amount of C (proves base pairing)

Sequence of bases in DNA determines kind of gene on chromosome

DNA Replication

occurs in nuclues

Parent DNA untwists, strands separate

N bases attach to complementary base (A to T, G to C)

2 Daughter DNA molecules-rewinds and formed

Polymerases- enzymes that make covalent bonds between nucleotides of new DNA strand

very unlikely to be paired incorrectly

DNA Polymerase and other protiens can repair damaged DNA

DNA harmed by: UV rays, X-rays, viruses

Replication begins at origins(beginning)

goes in both directions-forming a bubble

bubbles can merge

genetic instructions are copied for the next generation

Beadle and Tatum- one gene produces one speacific enzyme/protien/polypeptide

Sections on DNA code for certain amino acids

20 amino acids total

triplet codes-codons(necessary)

G,T,C,A(4) * G,T,C,A (4)= 16 (not enough

G,T,C,A(4) * G,T,C,A (4)*G,T,C,A(4)=64 different triplets(more than enough)

Next Scribe:Bridget

Scribe Post 11/19/10

In class on Friday, November 19th, we finished up the Genetics note packet, which is chapter 9 in our Biology textbooks.


pleiotrophy - occurs when ONE gene influences MANY physical traits




polygenic inheritance - when MANY genes effect ONE physical trait
-explains how parent can have offspring with different eye/skin color that they have


Genetics Disorder Crosses:

Dominant disorders include Achondroplasia (Dwarfism), Alzheimer's disease (mental disorder), Huntington's disease (mental disorder/uncontrollable movements), and Hypercholesterolemia (too much cholesterol in blood/heart disease). Requires at least one dominant allele to get these diseases. (Aa)

Recessive disorders include Albinism (white skin/hair/eyes), Cystic fibrosis (excessive mucus in lungs/liver, more vulnerable to infections), Sickle-cell disease (sickled red blood cells, damaged tissues), and Tay-Sachs disease (messed up brain cells). Requires 2 recessive alleles to get these diseases. (aa)

Types of Fetal Testing:
amniocentesis - extracting SAMPLE of baby's amniotic fluid, baby's cells, and karyotypes to check baby's status

chorionic villus sampling (CVS) - sample of fetal tissue cells from woman's placenta (fetus feeder/cleaner)

ultrasound imaging - uses sound waves to produce an image of the fetus (doesn't harm the baby)

fetoscopy - a tube with a scope is inserted into the uterus for a direct view

family history, blood tests, genetic counseling~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Potpourri (Pedigree Charts too) crosses

Chromosomal Theory of Inheritance - genes are located on chromosomes; inheritance patterns are explained by the behavior of chromosomes during meiosis

Gene Linkage - alleles that are on the same chromosome travel together during meiosis and fertilization which means they're inherited together. They DO NOT follow Mendel's principle of independent assortment.

Y Chromosome - MANLINESS, 1/3 size of X chromosome, has 1/100 as many genes as X chromosome, not much crossing over, passes intact from father to son, can trace ancestry of males based on Y chromosome


Next Scribe: Claire

Nov. 17, 2010

Scribe Post 11/17/10


Sally Y.



What did we do in class today?

• Went over UP pgs. 63~72

• Pedigree chart

• Homework: Lab #35, UP 92 A-F

• Possibility of a quiz tomorrow or Friday!

Pedigree Chart

What is a pedigree chart?

A pedigree chart is a chart that shows the phenotypes of an organism and its ancestors.



<---------- P1 Generation (Parents)

<---------- F1 Generation (Kids in birth order)

<---------- F2 Generation (Grandkids)

You can identify the phenotypes of each shape by looking at the key!

• every rectangle would be male and every circle would be female

• rectangle filled with only orange, we know that phenotype would be a colorblind male

• rectangle is filled entirely with yellow, it is a male with normal vision

• circle contains only yellow, it is a female with normal vision

• a circle with half orange and half yellow would have normal vision with a recessive gene

Note: If you are unsure of whether or not the gene is homozygous or recessive, leave the second allele blank. DO NOT ASSUME!

Next Scribe: James C

Scribe Post 11/16/10

Nov. 16, 2010.
CJ P.

Class contained:
Sex linked crosses
Blood type crosses
Incomplete dominance (blending phenotype ONLY)
Co-dominant (both traits show up)
Notes pages 8-9, and 12
Homework: Pages 63-72 and the extra credit and Lab 34

I. Sex linked Crosses
A. Genes are located only on sex chromosomes for sex-linked crosses
1. Mostly on the X chromosomes

This is how a sex-linked cross punnet square would look like:



There is no trait on the Y chromosome.










II. ABO Blood Groups
A. Types of blood
1. A= IAIA or IAi (DOMINANT)2. B=IBIB or IBi
3. AB= IAIB (CO-DOMINANT!)4. O= ii (RECESSIVE)

I-BLOOD CELL
Story time.

As Ms. Dillion says, If Sally had a baby, and she forgot who the father was, they could find the blood type of the baby, of Sally, and find the blood type of Sam, Joe, and Kevin.

Let's say Sally had 2 babies. One with blood type AB and one with O.
Sally's blood type is IBi
The father's blood type must be IAi. Congrats Kevin.
III. Incomplete Dominance
A. "Blends" together.
1. There is no dominant trait.
i. The "middle trait"

EX. If a red flower and a white flower cross, there will be pink flowers because there is no dominant color, they BLEND

IV. Co-Dominant
A. Both traits show up
1. They do not blend.
i. The traits are both dominant

If a black feathered chicken crosses with a white feathered chicken and both white and black are co-dominant, then their chickies will have black and white feathers, not gray because THEY DO NOT BLEND. THEY ARE BOTH DOMINANT COLORS.

SCRIBE: Sally.

Scribe Post 11/15/10

Notes:

Testcross:
used to determine true-breeding variety of plant (A_ x aa  cross an unknown dominant phenotype with a homozygous recessive to determine if second allele is A OR a.)

2-Factor Crosses:



















2 traits being passed on
- probabilities
2 coins flipped simultaneously.
Chance of tails/tails? 1/2 tails x 1/2 tails = 1/4.
- phenotypes
ratios, what you see
- genotypes
ratios, genes

*Within each trait, dominant allele before recessive.
*stay in the order of the traits that you are given
ex. SSyy
SsYY
SsYy
SSYy
ssYy
ssYY
Lab #34:
Probability
Mendel's Laws:  know these!!
-law of dominance
-law of segregation
-law of independent assortment

Read carefully!!

Homework:
Finish Lab #34, UP p.59-62

Make sure you understand Meiosis and Mitosis!!!

Next Scribe: CJ

Scribe Post: 11/12/10

****For this round you must COMMENT ON ALEAST TWO OTHER BLOG ENTRIES BESIDES YOUR OWN!!



Today was a busy day in Bio 173!!
We started off with a spot of notes; Set 2, Mendels's Laws, Pgs. 2-5



Basically....

-Parents pass on heritable factors to their offspring, which in turn, retain individuality generation after generation.
- Self vs. Cross Fertilization are different ways an organism may reproduce.

• Self fertilization, occuring in flowers, consists of two gametes being formed within one organism. This type of reproduction does not need another organism to reproduce.
• Cross fertilization, occuring in humans, consists of one gamete being formed in each individual and the other in another individual. This type of reproduction needs two individuals with diferent gametes.

- The first generation are call P for parent generation. The following generations that follow are F1, F2, F3 and so forth.

- Hybrids (Aa)- the offspring of two different true breeding varieties (AA+aa)

- Monohybrid Crosses- 1 trait being passed

- Allele- alternative forms of a gene

- Dominant vs. Recessive- AA (dominant) vs. aa (recessive)

- Genotype- Our genetic structure (non-visible); AA, Aa, aa

- Phenotype- What we can see; Physical traits (visible); tall, short, freckles..ect.

- Homozygous- same; AA or aa

- Heterozygous- Different; Aa














Mendel's 2 Principles



Mendel's principle of segregation:


- Pairs of alleles separate during gamete formation






















Mendel's principle of independant assortment:


- each pair of alleles segregates independantly of the other pairs during gamete formation (meiosis)




















HOMEWORK:
- 1 FACTOR CROSSES ON UP PGS. 55-57
- FACE LAB (COMPLETE THE ENTIRE THING), UP PGS. 45-50
- USE COLOR PENCILS!
- READ DIRECTIONS VERY CARFULLY!


NEXT SCRIBE: CHRISTINE K.

November 10

Kristen

Human Genetics

Today we reviewed meiosis for the quiz on Friday.

We did UP pg. 41 which measured the classes' different genetic traits such as tongue rolling, cleft chin, and Widow's peak.

We were also introduced to different terms on UP pg. 43-44.

Homozygous- two like genes for a given trait
ex. AA and aa

Heterozygous- has two different gene forms for a given trait.

ex. Aa

Phenotype- What a thing looks like
ex. What is the phenotype of a white cat? white.

Genotype- Genes that give the phenotype

ex. D (geno)= Dimples (pheno)

Complete Dominant Traits:

Dominant Gene- the gene that shows up in the heterozygous condition.

Recessive Gene- a gene that will give a phenotype only when in the homozygous condition.

Incomplete Dominant Traits- Neither gene is "hidden", both are expressed

ex. RR=red Rr=pink rr=white

Pure Breeding- organisms with genes only in the homozygous condition

ex. AA aa

Hybrids: (Aa, Gg)

Monohybrid- 1 trait

ex. Aa

Dihybrid- 2 traits

ex. AaBb

Trihybrid- 3 traits

ex. AaBbRR

This is where Punnet squares come in.

For Monohybrids, it is a 2 x 2 cross

For Dihybrids, it is a 4 x 4 cross

For Trihybrids, it is an 8 x 8 cross

Homework:
- QUIZ ON FRIDAY!!!!!
- EC UP pg. 39-40
- Read Ch. 9 pg 142-168

Next scribe: Aliza