Compendium Review Part II

Chapter 18
Chromosomes and The Cell Cycle
Chromosomes occur in 23 pairs in body cells.
• A Karyotype- is a visual display of a person’s chromosomes.
• The Cell Cycle- the cell cycle has two parts: Interphase & cell division.
-Interphase- Most of the cell cycle spends it’s time during interphase. It has three phases. The G (one) stage which double its organelles and occurs before DNA synthesis; S stage is when DNA replication and is during DNA synthesis; then the G (two) stage is the cell synthesizes the proteins needed for cell division and it occurs after DNA synthesis.

Cell division-After the cell enters interphase it then goes to cell division. The cell division has two stages. First of all the cell enters mitosis. Mitosis is a type of nuclear division. The second stage is cytokinesis is a division of the cytoplasm.






Comparison of Meiosis and Mitosis
• Meiosis and mitosis both have the same type of nuclear division.
• Mitosis has no pairing of chromosomes, is out of control when cancer occurs, is duplication division, it’s cell are exactly like the parent cell and is part of the cell cycle.
• Meiosis results into four daughter cells, is reduction division, it results in cells that are genetically different from the parent cell and is involved in gametogenesis.

Chromosome Inheritance
Meiosis is part of gametogenesis and contributes to genetic diversity. A person can be born with to many or too few autosomes or sex chromosomes due to nondisjunction during meiosis. Nondisjunction occurs when both members of a homologous pair go into the same daughter cell and fail to separate and both daughter chromosomes go into the same gamete. The most common known autosomal trisomy is Down syndrome.
Some can be born with to many or to few sex chromosomes such as turner syndrome, klinefelter syndrome, poly-X females and Jacobs syndrome. Chromosomal mutations can produce chromosomes with deleted, duplicated, inverted, or translocated segment. These syndromes are deletion syndromes and translocation syndromes.

Chapter 19

Cancer Cells
There are different type of characteristics of cancer cells: Cancer cells lack differentiation, cancer cells have abnormal nuclei, cancer cells from tumors, cancer cells have no need for growth factors, cancer cells gradually become abnormal and cancer cells undergo angiogenesis and metastasis. Mutation genes lead to uncontrollable growth in two types: Proto-oncogenes and tumor-suppressor genes. There are different types of cancer but the most common cancer is: breast cancer, prostate cancer, and colorectal cancer.

Causes and Prevention of Cancer
Some cancer can be heredity that is passed down from family like breast cancer or retinoblastoma tumor. Cancer is determined by a person’s genetic profile or exposure to environmental carcinogens. Cancer that is caused by the environmental factors is from radiation, tobacco smoke or pollutants. Also certain viruses can cause cancer like hepatitis B and C.
There are preventions of getting cancer like your lifestyle. Nutrition is a way to help prevent cancer, exercise, eating habits, no smoking or no drinking and to eat more fruit and vegetables.
Diagnosis of Cancer
The earlier a cancer is diagnosed the more likely it can be treated. A Pap test for cervical cancer, mammogram for breast cancer and some blood test can also detect cancer/tumors. If cancer does exist biopsy and imaging is used to confirm the diagnosis of cancer.
Treatment of Cancer
Today there are treatments for cancer and are different from one another. Surgery is used to removed the cancer but a person is at risk of having a relapse if a cancer cell is still in the body, radiation is used to kill cancer cells but had side affects and chemotherapy which is used to treat the whole body so no cancer cells can spread anywhere else in the body. There are also newer therapies that are being used to treat cancer.


Chapter 20
Patterns of Genetic Inheritance
Genotype and Phenotype
Genotype-refers to the genes of the individual
Phenotype-The physical appearance (the characteristics) associated with these alleles.
Homozygous dominant- (EE) has the dominant phenotype.
Homozygous recessive- (ee) has the recessive phenotype.
Heterozygous- (Ee) has the dominant phenotype.
One and two Trait Inheritance
The punnett square is useful to find out all the possible types of gametes.
The first step to doing is to determine the genotype and gametes.
Gametes: (D), (Pw)
Genotype: (Ll), (LlGg)
The reason why theses are different is that gametes cannot have the same letting such as (Aa) or (AaLl).

Beyond Simple Inheritance Patterns
In some patterns of inheritance, the alleles are not just dominant or recessive.
• Polygenic Inheritance- like skin color and height, are controlled by more than one set of alleles.
• Incomplete Dominance and Codominance- the heterozygote is intermediate between the two homozygotes. In codominance both dominant alleles are expressed equally.
• Multiple Allele Inheritance- The multiple allele inheritance pattern is exemplified in humans by blood type inheritance. Everyone has two out of three possible alleles: 1(a), I (b). both are expressed.
Sex-Linked Inheritance
Many genes on the X chromosomes, such as those that determine normal vision as opposed to color blindness, are unrelated to the gender of the individual.
• X linked Recessive Disorder of Interest- Color blindness, muscular dystrophy, and hemophilia.






Chapter 21
DNA Biology and Technology
DNA and RNA structure and Functions
DNA (deoxyribonucleic acid) is the genetic material and the DNA is largely found in the chromosomes, located in the nucleus of a cell.
DNA is a double helix
Each strands is a polynucleotide

Gene Expression
Gene expression leads to the formation of a product, usually a protein. Proteins differ by the sequence of their amino acids. Gene expression requires transcription and translation.
• Transcription
• Translation
Genomics
• A person’s genome can be modified
• Functional and comparative genomics
• Proteomics and Bioinformatics are new endeavors
DNA Technology
• Genes can be isolated and cloned
1. Gene cloning can be done to make copies of the same gene.
• Specific DNA sequences can be cloned
1. DNA fingerprinting
• Biotechnology Products
1. From bacteria
2. From Plants
3. From animals