Friday, December 10, 2010


today we learned how restriction enzymes cut DNA into fragments. Gel electrophore sorts macromolecules by charge and length. DNA fragments have a negative charge and move toward the positive pole smaller fragments move faster than larger ones

Wednesday, December 8, 2010


Genetic Engineering Notes

Today in class we started our notes on Unit 5: "Designer Genes"

DNA Technology- methods to study and manipulate genetic material.
  • corn can produce its own insecticid
  • Bacteria can clean up pollution
  • DNA fingerprints- to solve crimes
  • Advances toward curing fatal genetic diseases
4 Ways DNA technology Can Be Used:
  • Use of recombinant (recombine) to produce useful products
  • Use of DNA fingerprinting in forensic science
  • Comparison of genomes
  • Use of human gene therapy for treatment of diseases
3 Ways to Transfer DNA

1. Transformation- the taking up of DNA from the fluid surrounding a cell.

2. Transduction- the transfer of bacterial genes by a phage. The phage has a fragment of
DNA from its previous host cell. Now it is injected into the new host.

3. Conjugation- a "male" bacterial cell attaches to a "female"v cell by sex pili, a bridge forms, and DNA passes from the male to the female.

Here are some terms we went over today:

Biotechnology- the use of organisms to perform practical tasks.

ex: use of bacteria to produce cancer drugs and pesticides

Genetically Modified organism- an organism that carries recombinant DNA

Transgenic organism- a host that carries DNA from a different species

Cutting and Pasting DNA:

  • Restriction Enzymes- the cutting tools. These enzymes recognize short nucleotide sequences in DNA and cut at specific points.
  • Restriction site- the place where DNA is cut
  • staggered cuts yield 2 double stranded DNA fragments with single stranded "sticky ends"
  • Sticky ends are key to joining with other DNA
  • Join another DNA with 1st DNA
  • DNA ligase connects the DNA pieces
  • Result: a DNA recombinant molecule from 2 different sources

Obtaining the gene of interest: 2 ways

1. Using a radioactive DNA probe
2. Use reverse transcription to make an artificial DNA gene from mRNA

DNA Fingerprinting- a procedure that analyzes a person's unique collection of DNA restriction fragments. Used in forensics- determines whether 2 samples of DNA are from the same individual. Samples come from blood, semen,hair, skin or other biological evidence.

Homework: UP pg. 13-15, 7-10, 5-6

Next scribe: Davin

Wednesday, December 1, 2010

December 1, 2010

Scribe: Katie

  • Notes
  • Lab 37 work
- Review:
  • DNA --> RNA -->Protein
  • Genes determine protein which makes up your appearance and cell capabilities
  • Change in nucleotide sequence of DNA:
a. Base substitutions -replacement of one base for another. Can result in no change, critical, bad or good.
b. Base insertions or deletions - adding or subtracting nucleotides. Often results in disaster- can disrupt entire sequence of triplet pairings.
  • Mutagens - physical and chemical agents, such as UV light, X Rays, chemicals, carcinogens. These CAN cause mutations. They can also lead to diversity. DNA errors can also be due to unknown causes.

Lab info.

  • DNA has two strands, one will have a base sequence.
  • In the process of transcription, a strand of messenger RNA is transcribed with a sequence complimentary to the base sequence of the DNA. (this happens in the nucleus, DNA does not leave the nucleus, RNA does) **Remember RNA has U instead of T-- Uracil instead of Thymine**
  • During translation, codons, or sequences of nucleotides, form a code that specifies the order that amino acids, the "building blocks of protein", should be linked in a protein. Transfer RNA bring amino acids into place to be linked together with the according codons. In this process. the code in the messenger RNA, is translated into a special sequence of amino acids.(This all takes place attached on a ribosome in the cytoplasm)
  • When the ribosome is attached to the messenger RNA, transfer RNA carrying it's specific amino acid molecule, temporarily attached to the messenger RNA at its codon. Then, a transfer RNA molecule complimentary to the adjacent messenger RNA temporarily attaches to it. The ribosome then moves to that point of attachment on the messenger RNA. During each of those attachments, peptide bonds formed between the amino acids. And the transfer RNA molecules become free from the amino acids and RNA, and they can attach to another molecule of it's specific amino acid and carry it to another point along the messenger RNA. This is a growing chain that continues as ribosomes move along messenger RNA, as amino acids are added.
  • This pattern does not end until a termination codon is encountored. This gives the code for the translation to stop.


  • Finish lab 37
  • Do UP pages 99-110
  • Work on Tribune project (Due: 12/7)


Tuesday, November 30, 2010

Transcription and Translation

Bridget 11/30/10

  • A chart for reading genetic codes.... know how to read this for the test
  • find first letter in center of circle
  • find second letter in the 2nd row
  • find third letter in 3rd row
  • 61 codes for amino acids- 3 of them, UAA, UAG, and UGA tell the ribosomes to stop making the polypeptide
  • AUG= Methionine but also provides signal to start a polypeptide chain
  • Most codes are shared by all organisms
DNA Replication
  • making exact copies of DNA in nucleus, occurs before cell division(mitosis/meiosis
    enzyme= DNA polymerase

  • molecule of DNA is copied into a complementary strand of mRNA
    enzyme=RNA polymerase

Steps of Transcription:

  1. Initiation- RNA polymerase attaches to the DNA promoter nucleotide sequence on DNA, RNA is made
  2. RNA elongation- RNA grows longer, peels away from DNA, DNA strands come back together
  3. Termination-RNA polymerase reaches the end of the gene (the terminator), polymerase molecule detaches from RNA molecule and the gene
Processing RNA:
  • Prokaryotes- the mRNA is already ready
  • Eukaryotes- need to proccess, add extra nucleotides
  • cap and tail-protect RNA from enzymes, help ribosomes recognize it as mRNA
  • introns- bad, noncoding regions
  • exons- good, cooding regions
  • RNA splicing- introns removed before RNA leaves nucleus
  • Now mRNA is ready!!!!
  • mRNA (Messenger RNA) translated into tRNA (Transfer RNA)
  • mRNA goes to ribosome
  • 2 subunits made of proteins and rRNA (ribosomal RNA)
  • small subunit- binding site for mRNA
  • large subunit- binding site for tRNA
  • tRNA-twists and folds, end of folded molecule=anticodon
  • anticodon recognizes codon on mRNA, then the other end of the tRNA is where an amino acid can attach
  • Bonds between (AA)s ((amino acids)) are peptide bonds
  • The polypeptide that is growing and forming is the protein!!

Steps of Translation:
  1. Initiation- mRNA binds to small ribosomal subunit, tRNA attached to amino acid binds to start codon, AUG on mRNA; large ribosomal subunit binds to small one, which creates a working ribosome
  2. Elongation- amino acids are added to the first amino acid, creating a polypeptide chain
  3. Termination- one of the stop codons tells the translation to stop. Polypeptide is freed ( many A.A), and ribosome splits into its subunits
RNA has:
  • Ribose sugar
  • 1 strand
  • U instead of T
  • smaller than DNA, can go inside/outside nucleus
  • 3 types: mRNA, tRNA, rRNA
Next scribe: Katie!! :)
  • UP 99-110 due 12/2
  • Pre-lab 37- cut out????
  • DNA/ Chicago Tribune Project Due next Tues.

Monday, November 29, 2010


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

Double Helix

nucleotide=1 sugar, 1 phosphate, 1 base

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

Sunday, November 21, 2010

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.

- 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:

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 ch
romosomes; 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

Thursday, November 18, 2010

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

Tuesday, November 16, 2010

Scribe Post 11/16/10

Nov. 16, 2010.

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

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.

Monday, November 15, 2010

Scribe Post 11/15/10


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
Lab #34:
Mendel's Lawsknow these!!
-law of dominance
-law of segregation
-law of independent assortment

Read carefully!!

Finish Lab #34, UP p.59-62

Make sure you understand Meiosis and Mitosis!!!

Next Scribe: CJ

Sunday, November 14, 2010

Scribe Post: 11/12/10


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


-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)



Thursday, November 11, 2010

November 10


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

- EC UP pg. 39-40
- Read Ch. 9 pg 142-168

Next scribe: Aliza

Tuesday, November 9, 2010

Nov. 9

Today we finished the notes packet of Meiosis, did a demo of meiosis using
beads and magnets, and started the lab on UP 19-37.


Nondisjunction: The chromosomes fail

to separate at Anaphase I or II. Occurs

with autosomes or sex chromosomes.

Nondisfunction causes some syndromes like
Klinefelter syndrome for males and Turner
syndrome for females.

Those syndromes cause almost like a steroid effect. For the people effected by these syndromes, they may become sterile.
Klinefelter syndrome: males, XXY: have 47 chromosomes instead of 46
Turner syndrome: females, XO: have 45 chromosomes and only one X chromosome.
Breakage of a Chromosome:
Deletion: part of chromosome is lost or removed
Duplication: a region of the chromosome is repeated
Inversion: a segment of the chromosome repositions and reverses the order of the genes

Translocation: one part of a chromosome goes on another chromosome and that piece cannot be found

next scribe: Kristin

Monday, November 8, 2010


Yunsu Y.
Today we took notes on MEIOSIS.

Meiosis goes through reduction division, 2 part division. Reduction=reduce , Division= Separate sister chromatids. Meiosis occurs in the ovaries or testes. It starts with a diploid parent cell then goes into prophase 1, metaphase I, anapahse I, telophase I, prophase II, metaphase II, anaphase II, then telophase II. The cell goes through each step twice but it does not really go through interphase II. It "goes" through interphase II, but it is just a resting period, it does not go through the same steps like in interphase I because it does not need to synthesize more chromosomes. (No G1, S, or G2 just stays the same.) These phases are very similar to mitosis, but are slightly different and have different end products.

1. Metaphase I: the homologous pairs of chromosomes called tetrads, line up in the middle.
2. Telophase II: instead of having 2 daughters cells, like in mitosis, you end up with 4. They also are not genetically identical.

Through meiosis, egg and sperm (gametes) cells are produced, not like mitosis where many different kinds of cells can be produced. Remember because this is sexual reproduction there are variations among offsprings. This variations amoung offspring occurs because of independent assortment and random fertilization.

1. Independent Assortment: when the chromosomes line up, there is no specific way it is all by chance.
2. Random Fertilization: a random pairing of 1 egg to 1 sperm, many different combinations.

Crossing over: where genetic material gets exchanged, segments of homologous chromatids.
-Crossing over happens because the genetic material gets tangled and they cross, so when they divide the daughter cells are not all the same. This would occur in prophase I.
There are somatic cells and sex cells---
1. Somatic cells: out body cells which are diploid -46 chromosomes for humans.
2. Sex cells: Sperm and egg which are haploid -23 chromosomes for humans.
-The end products of meiosis are sex cells that are haploid cells (n) and the parent cells in the beginning are diploid cells (2n). The diploid is the total number of chromosomes, 2 sets. Haploid is half the number of chromosomes.
★It is important to remember that end products of meiosis are haploid. They have to be haploid so that when an egg meets a sperm it can create a full human equaling 46 chromosomes. (23+23=46)
-Each human has sex chromosomes, usually 2. Females have XX and males have XY, so since 2 are sex chromosomes there are 44 leftover chromosomes. These are called autosomes. (not sex)

These are karyotypes of female and males humans.
-On the left is the female and on the bottom is the male. You can tell by the difference of the last 2 sex chromosomes.
-You can see that the first somatic chromosome is the largest and the last somatic chromosome is the smallest.

We also watched a video on meiosis:
1. There are 4 egg cells and 4 sperms cells produced. All 4 of the sperm cells are viable but only 1 of the 4 eggs will be used and mature, the other 3 eggs are useless.
2. Centrioles move before the second division, making a right angle to the first location of the centriole at the first division.

Homework: UP. pgs 15-16B, Study Meiosis, Read Up pgs 13-14, Cut out pg 21 for tomorrows lab

Next scribe: Carey E

Friday, October 29, 2010

Friday, Oct. 29th, 2010

How Allergies Develop

Develops in two stages:

1. The first exposure to the allergen causes sensitization (you get sensitive).

2. The following exposures of the same allergen cause allergy symptoms.

• Histamine – a chemical that reacts to an allergy

• We take anti-histamine when we get allergies to fight them off

The Details

1. Allergen enters the blood stream.

2. B cells make the antibodies

3. The antibodies attach themselves to the mast cell.

4. Allergen binds onto the antibodies on the mast cell.

5. Histamine is released and starts causing allergy symptoms.

Allergens usually tend to enter through the nose and the throat so symptoms are most abundant in these areas.

Anaphylactic shock – sudden releases of inflammatory chemicals into the body of people with extreme sensitivity to certain allergens such as:

• Bee stings

• Peanuts

• Shellfish

So what happens?

Blood vessels expand greatly causing a great drop in blood pressure, a condition also known as shock.

Anaphylactic shock can be fought off with injections of epinephrine (adrenaline).

Common Autoimmune Diseases

Rheumatoid Arthritis – causing damage and inflammation of bone joints due to T-cell attack

Juvenile Diabetes – a cell-mediated attack of insulin that produces cells in the pancreas

Multiple Sclerosis – T-cells attack the myelin sheath (fatty tissue) of neurons

Lupus – immune attack on skin and vital organs

Every disease or infection has a different reaction depending on how weak or strong your immune system is.

Immunological basis for organ/skin graft rejection?

Transplant Rejection – an immune system recognizes the donor’s cells or organs as foreign and starts attacking

Donors with self proteins that match the recipient’s as closely as possible are used in order to minimize rejection.

Drugs are used to hold back to suppress the immune system. The donors and recipients may not be related.

Immunodeficiency Diseases


1. SCID (Severe Combined Immunodeficiency) – a case where someone does not have functional T and B cells; as a result, they do not have specific responses.

2. Hodgkin Disease – a type of cancer that affects the number of lymphocytes, affecting the T and B cells.


AIDS (Acquired Immune Deficiency Syndrome)

HIV attacks the helper T cells that activate T bells and B cells.

Since 1981, AIDS has killed more than 20 million people, and 40 million people are living with the virus. Over 1/3 of the adult population in Africa has been infected as well.

Death is usually not a result of HIV, but because of other life threatening infections.

Next Scribe: Yunsu Yu

Thursday, October 28, 2010

Immune System: T Cells, Allergies, Cancer, Immunity, Immune Response

Disease and the Immune System

After taking a quiz and finish the spice lab we went over these notes:

Supresser T Cells: get concentrations back to normal after the infection goes away

Cytotoxic T Cells: help protect body fro own cells if they become cancerous
-sometimes cancer is hard to fight because our bodies don't reconize our own cells as cancerous

Immune system has a "memory"
-our bodies remember the antigens we have encountered
-if we encounter the same antigen again, our immune system destroys them before symptoms occur

Immunity: resistance to specific invader
-can be done actively or passively

Active Immunity: body produces antibodies in its own defense
-if antibodies are produced, so are memory cells
2 ways:
-having disease
-vaccination: injection of weakened variant of disease-carrying microbe or one of it's components

Passive Immunity: receiving pre-made antibodies
-through mother's blood stream (baby's can't produce antibodies)
-through shot containing antibodies produced by another organism
Ex: Tetnus shot- gives you antibodies, not the pathogen because the pathogen is too dangerous and harmful, can get sick from it.
-have to get these shots more than once, no memory cells are produced

Primary Immune Response:
- first exposure of lymphocytes to an antigen
-takes days to produce antibodies-through colonal selection
-memory cells produced to remember antigen
-these are located in lymph nodes and live for decades

Secondary Immune Response:
-occurs when the same antigen is encountered again
-memory cells multiply leading to production of antibodies
-more effective than primary immune response
-person is symptom free
-could offer lifelong immunity

You can get infected by the same pathogen twice, but only get sick from it the first time because memory cells are produced

Immune Disorders: consequence of malfunctioning immune system
-allergies: sensitivity to antigens in environment
-how they are developed: 1st exposure to allergen cause sensitization, following exposures to same allergen produce symptoms
-Autoimmune Disorder: immune system fights its own molecules-vey bad
-Immunodeficiency Disease: body lacks part(s) of immune system

Next Scribe: Sally Y

Scribe Post: 10/26/10

Today was a big day in Biology!

We started to plan out our independant spice labs. Accompanied with that was the assignment to get your experiment approved by Mrs. Andrews. When approved, we were to turn in a lab report up until the procedure part.

Spice Lab:
An independant lab that we invent and carry out by oursleves. We are to measure the zone of inhibition in the bacteria, Bacilis subtilis. We are to perform the lab and to write a lab report.
The finished lab report is due on 11/8/10. Guidelines are:
-Materials have to be LIQUID
-Must have TESTABLE AND MEASURABLE hypothesis
-Have multiple trials
-Can only use 4-5 Petri dishes
-Can vary in concentration, product brand..ect
-Compare and contrast products.

In your lab report, remember to:
- Include background on ALL of your materials (should vary with group members)
- Match your procedure with your group's
- Use roman numerals, letters, and numbers for every section of your report
- Have an ORIGINAL title
- Must incude how/when to gather data (give times; 24 hours, 2 days..ect.)
- Include charts and graphs
- Lab report guidlines on UP pg. 43 and in Survival pk. pg. 13

- Read UP pgs 37-38
- Re-read chp 24
- Review notes

next scribe: Bridget S.

Wednesday, October 27, 2010

October 27, 2010, B-Cells and T-Cells

Today, we watched two short movie clips.

One was about the role of an antibody.

  • neutralization
  • aggulination
  • precipitation
  • complement proteins
The other was about:
  • humoral immunity- provided by B-cells, defends primarily vs. bacteria and viruses present in body fluids
  • clonal selection
Notes: Page 21, 23, 24
Clonal Selection
  • When an antigen enters the body fluids, it binds with B-Cells that have complementary receptors
  • The B-cells are then activated; they grow and divide, creating effector cells
  • These cells then secrete antibodies specific to that antigen
  • plasma cells- make the antibodies
  • memory cells- "remember," this is why you don't get the same exact infection again because your body produced the antibodies needed to fight that infection
  • Cell-mediated immunity
  • Respond to antigens that have already entered the body
  • More "hands on" than B-Cells
  • 3 kinds- Helper T-Cells, Cytotoxic T-Cells, and Supressor T-Cells
Helper T-Cells
  • Macrophages engulf a microbe, produce antigens, and displays the foreign antigens on the cell membrane
  • it is essentially saying "I found something and I don't think it's good!"
  • The Helper T-Cell binds to the macrophage at the site and determines if it is good or bad
  • If bad, the Helper T-Cell divides, produces memory cells, and stimulates activity of cytotoxic T-Cells
Cytotoxic T-Cells (Killer T-Cells)
  • Identifies infected body cells and binds to them
  • Discharges perforin which is a protein that creates a hole in the infected cell's membrane, causing it to die.
  • This needs to happen because the infected cell has become a factory of pathogens and the body needs to have it shut down.
  • UP pgs. 47 and 57
  • UP pg. 5 What is Ecology Good For (E.C.)
  • Work on Lab Report, Due: 11/8
  • The Test may be on Tuesday, but please still plan on Friday!!!
Next Scribe:
  • Claire T

Monday, October 25, 2010

October 25, Immune System

Using cell signaling, a healthy cell makes proteins which inhibit viral replication, meaning it kills off the exported viruses that the bad cell releases.

2. Prostaglandins. Inscreases blood flow to the wound area = RED and WARM.
i. Also sends pain signals to brain. AH! Brain, help me!3. Pyrons. travel to the hypothalamus (it's in the brain and it analyzes your blood.) They cause a low fever which is GOOD because the heat makes the enzymes work faster.

III. Lymphatic System
A. Two main functions
1. To return tissue fluid to circulatory syste
2. To fight infection.
It's a highway of vessels that touches upon every part of your body so they can react fast when tissue is damaged.

Scribe: Aliza R.

Thursday, October 21, 2010

October 21

Today, we viewed our dishes with agar in them that we worked on yesterday, and we put our results in our packets. Also, UP pg. 33 was completed, and it wasn't too hard, so there isn't much time needed to complete this task. We went over UP pgs. 31-32, these pages give you a better idea of how certain diseases differentiate between each other. Finally, we also completed the notes on bacteria that we left off from yesterday, and we took notes until the page entitled:
"Nonspecific diseases". So, if you wish to look at the notes, go into moodle under Mrs. Andrews' name, and the notes should show up.

This hereby concludes today's blog

next scribe - CJ

October 20th

o Set up Bacteria lab (UP pg. 19-25)
o Chapter notes- (pg. 10-top 13)

We looked at some important notes
Bacteria Cell:o They have no nucleus
o Most have cell wall exterior to plasma membraneo 50% are Motile (can move)
o Sessile- stationary

3 types of bacteria:o Cocci: spheres
o Bacilli: rod-shaped
o Spirochete: spiral-shaped

Bacteria Reproduction:o Can reproduce if conditions are favorable
o Their cells divide through binary fission
conjugation - sexual reproduction with 2 different bacteria cells

Endospore:o Can survive extended periods in harsh conditions
o Lack of water/ nutrients
o Extreme temperatures
o Most are poisons
o Found in some prokaryotes
o Outer cell produces the Endospore
o Outer cell may disappear, but Endospore survives
o Some can remain like this for centuries

Impact of Prokaryotes on Humans:o Disease- causing Bacteria
o Exotoxins: poisonous proteins secreted by the bacteria cells
o Often causes vomiting and diarrhea
o Endotoxins: chemical components of the cell wall on the cell
o Often causes fever, aches, drop in BP

Power of Antibiotics:o Zone of Inhibition: the areas where the growth of bacteria is prevented (inhibited) by an antibiotic or other substance

next scribe - Skyler

Wednesday, October 20, 2010

October 18th

Today we learned how we get sick. Pathogens are one way to get sick.
Viruses are considered both life and non life, since they ahve characteristics of both.
Life: Highly organized with genes
Non-Life: not cellular, cannot reproduce on own

Viruses infect a living cell. one way they do this is the lyctic cycle, where DNA is injected by virus into host cell to produce copies of virus.
DNA viruses usually reproduce in host cell's cytoplasm, sometimes in nucleus.
Prokaryotes have been around for 2 billion years.

Next Scribe - Nick

Sunday, October 10, 2010

MITOSIS 10/8/10

Unit 2 - CELLS
MITOSIS = cell division

Scribe Post for Friday, 10/8/10

Cells divide to replace damaged cells, reproduce organisms, to grow, to transfer genes from cell to cell, and for a unicellular organism to become multicellular

Sexual (MEIOSIS)- fertilization of an egg by sperm (each contain half of the parent cell's chromosomes), occurs in reproductive organs (ovaries/testes)

(MITOSIS)- no fertilization at all, parent and offspring have the same genes, binary fission (organism splits into 2, found in single celled organisms)


-Contain almost all genes of a eukaryotic cell
-Visible with light microscope during cell division
-Chromatin (invisible) are masses of long thin fibers, contain DNA/protein
-Before cell division, chromatin coils up to form chromosomes
-Humans have 46 chromosomes (varies by species)
-Each chromosome can have over 1,000 genes

Chromosome Replication

-Genetic material must be doubled before cell division to make sure that the daughter cells match the parent cell
--Sister chromatids are identical copies of each other connected at the centromere
--Daughter cells are the result of cell division, DOES NOT IMPLY GENDER

The Cell Cycle

Interphase (Pre-Mitosis) - 90% of cell cycle
-GI (Gap 1) - cell grows 2x bigger, protein synthesis, more organelles, 2x cytoplasm
-S (Synthesis) - chromosome replication (in nucleus)
-G2 (Gap 2) - Final preparation before division
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-Chromosomes coil/condense to become visible
-Nucleoli disappears
-Sister chromatids connected at centromere
-Spindle forms

-Nuclear envelope breaks down
-Spindle attaches to centromeres and move chromosomes to center of cell

-Spindle completely formed
-Centromeres on chromosomes are lined up on equator between the poles
-Spindle is attached to each sister chromatid, pushes chromosomes to center


-Sister chromatids are separated and each are now known as daughter chromosomes
-Motor proteins on centromeres move chromosomes toward opposite pole of cell
-Spindle attached to chromosomes shorten
-Spindle not attached to chromosomes lengthen to extend cell and force poles further apart to prepare for daughter cells


-Begins once chromosomes reach poles
-Opposite of Prophase
--Nuclear envelope REAPPEARS
--Nucleoli REAPPEAR
--Chromosomes UNCOIL


-Begins during telophase
-'CLEAVAGE' in animal cells
-cleavage = indent at equator of cell that pinches cell in 2
-Formed by ring of microfilaments inside cell membrane
-In plant cells, cell plate forms by starting in center of cell and moving outward to bisect cell

Cell Cycle Control

-Cells that are not directed by the cell cycle divide out of control
-Result is a benign tumor (abnormal mass of normal cells)
--can cause problems depending on location
--as it grows, displaces normal tissue


-Cancer cells have faulty cell cycle, divide out of control
-Malignant tumor = lump that results from division of cancer cell
-Metastasis = spreading of cancer cells to other organs
-Cancer is named for where they begin
--Carcinomas - originate in external/internal coverings of body
--Sarcomas - originate in tissues that support body
--Leukemia - cancer of blood forming tissue (bone marrow)
--Lymphomas - cancer of blood forming tissue (lymph nodes)

Cancer Treatments

Radiation Therapy

-Cancer cells exposed to high-energy radiation disrupt cell division
-Radiation destroys cancer cells without harming normal cells
-Bad side effects (sterility)


-Drugs that disrupt cell division
-Antimitotic drugs - prevent cell division by interfering with spindle formation