Com 18-21

Chapter 18 Patterns of Chromosome in heritance

18.1 Chromosome and the cell cycle

Humans carry 46 chromosomes at all times these are in 23 pairs. 22 of these are autosomes and 1 pair of these is the sex chromosomes. Males have and X and Y. The females have two X chromosomes.

The Cell Cycle

The cell cycle is an orderly process that has two parts: interphase and cell division.
· The interphase is where the cell spends most its time.
o G1 stage: The cell doubles it organelles and it accumulates the materials need for DNA synthesis.
o S stage the DNA replication occurs.
o G2 stage the cell synthesizes the proteins need for cell division.

· Cell Division
o Mitotic stage distributes two sister chromosomes into the cell
o Cytokinesis is the division of the cytoplasm,

18.2 Mitosis
Prophase
Prophase

o The chromosomes condense and are visible.
o Nuclear envelope fragment
o The nucleus disappears.
o The centrosomes to opposite sides
o The spindle fibers appear

Metaphase

Metaphase

o The chromosomes then line up in the middle of the cell,
o The spindle is now fully formed.

Anaphase

o The sister chromatics separate at the middle and start to move towards the “poles”
This a picture showing the telophase

The telophase and Cytokinesis

o The chromosomes finally make it to there destination.
o The nuclei reappears
o The spindle disappears
o The nuclear envelope is put back together again
o This all works towards making two identical daughter cells.

18.3 Meiosis
Prophase 1

Prophase 1

o Meiosis is part of the sexual reproduction
o Synapsis occurs
o The spindle forms
o The nuclear envelope fragments
o During synapsis homologous chromosomes come together and line up side by side.
o An exchange of genetic material may occur now “Crossing Over”

Metaphase 1

o Homologous pairs align independently at the equator.

18.4 Comparison of Meiosis and Mitosis

o Homologous chromosomes pair and undergo crossing over during prophase 1 or meiosis but not during mitosis
o Paired homologous chromosomes align at the equator during metaphase 1 in meiosis. These paired chromosomes have 4 chromitids altogether individual chromosomes align at the equator during metaphase in mitosis. They each have two chromatids.
o Meiosis 2 and mitosis is the same except that the nuclei contain the haploid number of chromosomes.

Spermatogenesis and Oogenesis

The spermatogenesis is the production of sperm in males. After the sexual organs become mature the average male will produce 300,000 a minute, (400 mil a day) even though there are so many only a fractions will ever get the chance to fertilize an egg.
Oogenesis is the production of eggs in the female. A mature egg has 23 chromosomes.

18.5 Chromosome Inheritance

if an egg has 24 chromosomes rather then 23 then trisomy occurs. If the egg has 22 rather then 23 then monosomy occurs. These will both create a Barr Body. When an extra Y is present then Jacobs Syndrome occurs. Down syndrome other wise know as trisomy 21. Someone born with only one sex chromosome then its Turner syndrome. Klinefelter happens in about 1 in 650 males, they are born with two X chromosomes and a Y chromosome. Only about 25% of males that have it will ever be diagnosed.

Chapter 19 Cancer

19.1 Cancer Cells

Cancer cells lack differentiation
They have an abnormal nuclei (they are enlarged and have an abnormal of chromosomes)
They have unlimited replicate potential.
They form tumors
Cancer cells have no need for growth factors
Cancer cells gradually become abnormal
Through Carinogenesis
Initiation: a single cell undergoes a mutation that causes it to begin to divide repeatedly
Promotion: a tumor develops and the tumor cells continue to divide. As they divide they undergo mutation
Progression: one cell undergoes a mutation that gives it a selective advantage over the other cells. This process is repeated several times and eventually there is a cell that has the ability to invade surrounding tissues.
§ They undergo Angiogenesis and Metastasis

Cancer is a genetic Disease

1. Proto-oncogenes: is the code for proteins that promote the cell cycle and prevent apoptosis, they are often likened to the gas pedal of a car because they cause acceleration.
2. Tumor-suppressor genes: code for proteins that inhibit the cell cycle and promote apoptosis, they are often likened to the brakes of the car because they inhibit acceleration

Types of cancer

A patient’s prognosis is determined by two different stages:
1. whether the tumor has invaded the surrounding tissue
2. whether there are metastatic tumors in distant parts of the body

Prostate cancer

Classification of tumors:
1. Carcinomas: cancers of the epithelial tissues and Aden-carcinomas are tumors of the glandular cells. This includes:
a. Skin
b. Breast
c. Liver
d. Pancreas
e. Intestines
f. Lung
g. Prostate
h. Thyroid
2. Sarcomas are cancers that arise in the muscles and connective tissue. Such as bone and fibrous connective tissue.
3. Leukemia’s are cancers of the blood
4. Lymphomas are cancers of the lymphatic system

Breast cancer is the most common type of cancer that is found in the body. (Mainly in women) For males the most common type of cancer is prostate cancer.
Skin Cancer

19.2 Causes and Prevention of Cancer

The causes of cancer are genetics and environmental carcinogens
§ Radiation
o UV lights, radon gas, nuclear fuel, and X-ray.
§ These are responsible for:
· Skin Cancer
§ Organic Chemicals
o Such as tobacco smoke
§ These contain chemicals that can cause mutations:
· Larynx
· Esophagus
· Pancreas
· Bladder
· Kidney
· cervix
o Pollutants
§ Chemicals and pesticides
· Lung disease
· Lung cancer
o And Viruses
§ Hep B an C
Epstein-Barr

§ Epstein-Barr Virus
§ HPV
· Liver cancer
· Cervical Cancer
· Nasopharyngeal cancer

§ Dietary choices have also shown evidence that it can play a role in it.
o Such as high fat content:
§ Breast and prostate cancer

19.3 Diagnosis of Cancer

There are seven warning signs:
1. C- Change in bowel or bladder habits
2. A- a sore that does not heal
3. U- unusual bleeding or discharge
4. T- Thickening or lump in breast or elsewhere
5. I- indigestion or difficulty in swallowing
6. O- Obvious change in wart or mole
7. N- Nagging cough or hoarseness

Routine screening tests:
Self-Examination tests:
1. ABCD’s of melanoma
a. Asymmetry
b. Border, irregular scalloped or poorly circumscribed border.
c. Color, Varied from one area to another. Shades of tan, brown, black, red, white, and blue.
d. Diameter, larger then 6mm
2. Mammogram
3. Pap smear
4. Colonoscopy

Tumor marker tests are a blood test for tumor antigens and antibodies.
Genetic tests for mutations in proto-oncogenes and tumor suppressor. These are available for breast, colon, bladder, thyroid, and melanoma.

19.4 Treatment of Cancer

The standard therapies:
Surgery
Radiation
Chemo
Bone marrow transplants
Newer treatments:
Immunotherapy
Passive immunotherapy
P53 gene
Angiogenesis

Chapter 20 Patterns of Genetic Inheritance

20.1 Genotype and Phenotype
The genotype of a human refers to the genes of an individual,

20.2 One and Two trait Inheritance

One and two trait inheritance has to do with the recessive and dominate traits. Each trait has a link between being recessive which means that it will take two recessive genes of each parent to pass it on to there children, some others are dominate and need only one to pass it on to there children.

Different genetic disorders those are recessive:
a. Tay- sachs
b. Phenylketonuria
c. Sickle cell
Different genetic disorders that are dominate:
a. Marfan syndrome
b. Huntington disease

20.4 Sex-linked Inheritance

Autosomes are the 22 chromsomes out of the 23 chromosomes. The 1 chromosome that is left is the sex chromosomes these determine the sex of the human. The traits that are from the genes of the sex chromosomes are said to be sex linked. The allele of the x chromosome is X-linked. And the same for the Y.

Chapter 21 DNA Biology and Technology

21.1 DNA and RNA structure and Function

The structure of DNA is double helix.

Replication of DNA

When an exact copy is made of the DNA helix then it is considered to be DNA replication.
1. Before replication begins the two strands that make up the parental DNA are hydrogen bonded to each other.\
2. an enzyme unwinds and unzips double stranded DNA
3. New complementary DNA nucleotides, always present in the nucleus, fit into place by the process of complementary base pairing. These are positioned and joined by the enzyme DNA polymerase
4. To complete replication an enzyme seals any breaks in the sugar phosphate backbone.
5. The two double helix molecules are identical to each other and to the original DNA molecule.

The structure and replication of RNA

RNA is single stranded and is translated unlike DNA that is transcribed.

21.2 Gene Expression

Transcription
Happens in the Nucleus
DNA double helix opens up
mRNA transcript is made from the DNA template
Translation
Happens outside the nucleus
ribosome’s do the translation
they glom onto the mRNA and line up the acids according to he mRNA code
The regulation of gene expression

1. Transcriptional control
a. Chromatin density and transcription control
2. posttranscriptional control
a. mRNA processing
3. translational code
a. Differential ability of mRNA due to ribosome’s
4. post translation code
a. changes to the protein to make it functional
When the regulation of a gene is out of control then cancer takes its place.

21.3 Genomics

proteomics is the study of the structure, function, and interaction of cellular proteins.

Bioinformatics is the application of computer technologies to the study of the genome.

This can be modified through
1. ex vivo gene therapy
a. bone marrow stem cells are removed and infected with the RNA retrovirus
b. this carries the normal gene
c. Then returned to the patient.
2. in vivo gene therapy:
a. the gene needed to cure cystic fibrosis is sprayed up the nose
b. or delivered to the lower respiratory tract by adeno viruses

21.4 DNA technology

Recombinant DNA
DNA sequencing and human genome project
Genetic engineering

These are the websites that I was able to get some information off of:

http://virtual.yosemite.cc.ca.us/randerson/Lynn

library.thinkquest.org/.../mitosis.gif

http://micro.magnet.fsu.edu/cells/fluorescencemitosis/images/cytokinesissmall.jpg

www.lib.uiowa.edu/hardin/md/pictures22/dermne...

http://www.breasthealthfocus.com/articles/images/imgCancerSymptoms.gif

http://www.meb.uni-bonn.de/cancer.gov/Media/CDR0000442273.jpg

commons.wikimedia.org/wiki/Image:Epstein_Barr...

http://www.dartmouth.edu/~toxmetal/images/sicklecell.jpg

http://www.allaboutarthritis.com/image/stock_image/marfan_syndrome02.jpg

www.ch.cam.ac.uk/.../molecules/nucleic/dna1.jpg