Genetics
Cell division
-mitosis
-meiosis
Role of DNA/genes in controlling cell metabolism
DNA technology
Cellular basic for cancers
Early fetal development
Role of genes, chromosomes in inheritance
Cell division
-mitosis
-meiosis
Role of DNA/genes in controlling cell metabolism
DNA technology
Cellular basic for cancers
Early fetal development
Role of genes, chromosomes in inheritance
Cell division
Cell division takes place after interphase which is where the cell prepares itself for cell division by the number of organelles doubles, the cell grows larger, chromatin doubles as DNA synthesis takes place. Mitosis and meiosis are two types of cell division. There are two stages to cell division the first being mitosis and the second cytokinesis. Each cell has 23 pairs of chromosomes which is the genetic makeup of organisms from hair color, height, and gender. This is referred to as DNA. Each chromosome is duplicated composing of two
sister chromatids held together with centromere. In the first phase of mitosis the centrosomes have duplicated, nucleus has disappeared, and the chromosomes have duplicated into sister chromatids. In the metaphase each chromatid attaches to spindle fibers. The centromere holding the sister chromatid together is fully formed and all chromatid is aligned in the middle of cell. In anaphase the spindle fibers pull apart the sister chromatids to opposing sides of cell to become daughter chromosomes. Each side of cell receives the same number of chromosomes (23 pairs) and of the same kind. The last phase is telophase. Where each daughter cell forms and in it a nucleus and nucleoli reappear. Daughter cells are diploids (2n) because they have a complete number of chromosomes and are identical to there parent cell. The second stage cytokinesis is where the cytoplasm and organelles divides. This the last part of cell division where the two daughter cells formed are encompassed by a cleavage furrow. This cleavage furrow is a slight indentation that pinches the cell in half and each daughter cell then has its own plasma membrane.
Cell division takes place after interphase which is where the cell prepares itself for cell division by the number of organelles doubles, the cell grows larger, chromatin doubles as DNA synthesis takes place. Mitosis and meiosis are two types of cell division. There are two stages to cell division the first being mitosis and the second cytokinesis. Each cell has 23 pairs of chromosomes which is the genetic makeup of organisms from hair color, height, and gender. This is referred to as DNA. Each chromosome is duplicated composing of two
sister chromatids held together with centromere. In the first phase of mitosis the centrosomes have duplicated, nucleus has disappeared, and the chromosomes have duplicated into sister chromatids. In the metaphase each chromatid attaches to spindle fibers. The centromere holding the sister chromatid together is fully formed and all chromatid is aligned in the middle of cell. In anaphase the spindle fibers pull apart the sister chromatids to opposing sides of cell to become daughter chromosomes. Each side of cell receives the same number of chromosomes (23 pairs) and of the same kind. The last phase is telophase. Where each daughter cell forms and in it a nucleus and nucleoli reappear. Daughter cells are diploids (2n) because they have a complete number of chromosomes and are identical to there parent cell. The second stage cytokinesis is where the cytoplasm and organelles divides. This the last part of cell division where the two daughter cells formed are encompassed by a cleavage furrow. This cleavage furrow is a slight indentation that pinches the cell in half and each daughter cell then has its own plasma membrane.Meiosis 1 is a lot like mitosis but with distinct differences. During the metaphase 1 in meiosis the 
sister chromatids are not spit apart by the spindle fibers instead each sister chromatid is each pair of chromosomes goes through synapsis and crossing-over. These homologous pairs are aligned in the center of the cell just like in mitosis. In anaphase 1 spindle fibers separate the homologous pairs to opposing sides of cell. The following phases are the same except that in the end the daughter cells have one chromosome from each homologous pair. The daughter cells are haploid (n) half of parent cell. In mitosis 2 the daughter cells go through cell division again with the sister chromatids separating resulting in a total of four haploid daughter cells that go one to become gametes.
Role of DNA
DNA (deoxyribonucleic acid) a genetic material that makes exact copies of its self so that all cells are identical. DNA is a double helix that is composed of two sides like a ladder with rungs connecting the two and it spirals about each other. The sides are composed of sugar and phosphates molecules and the rungs are complementary bases. DNA
located in the nucleus stores genetic information and provides the cell with directions on protein synthesis. RNA also a nucleic acid like DNA helps DNA carry out the genetic information in the form of Messenger RNA (mRNA). Messenger RNA carries this genetic information to the ribosomes in the cytoplasm where other RNA molecules bring about protein synthesis. Protein synthesis can only occur if translation takes place. The first step is to make a faithful copy of DNA by copying a sequence of nucleotides in DNA to a sequence of nucleotides in mRNA, called transcription. Then this sequence of nucleotides is translated into a sequence of amino acids called the genetic code. The genetic code puts together protein in the cell which are used as the cells metabolism.
sister chromatids are not spit apart by the spindle fibers instead each sister chromatid is each pair of chromosomes goes through synapsis and crossing-over. These homologous pairs are aligned in the center of the cell just like in mitosis. In anaphase 1 spindle fibers separate the homologous pairs to opposing sides of cell. The following phases are the same except that in the end the daughter cells have one chromosome from each homologous pair. The daughter cells are haploid (n) half of parent cell. In mitosis 2 the daughter cells go through cell division again with the sister chromatids separating resulting in a total of four haploid daughter cells that go one to become gametes.Role of DNA
DNA (deoxyribonucleic acid) a genetic material that makes exact copies of its self so that all cells are identical. DNA is a double helix that is composed of two sides like a ladder with rungs connecting the two and it spirals about each other. The sides are composed of sugar and phosphates molecules and the rungs are complementary bases. DNA
located in the nucleus stores genetic information and provides the cell with directions on protein synthesis. RNA also a nucleic acid like DNA helps DNA carry out the genetic information in the form of Messenger RNA (mRNA). Messenger RNA carries this genetic information to the ribosomes in the cytoplasm where other RNA molecules bring about protein synthesis. Protein synthesis can only occur if translation takes place. The first step is to make a faithful copy of DNA by copying a sequence of nucleotides in DNA to a sequence of nucleotides in mRNA, called transcription. Then this sequence of nucleotides is translated into a sequence of amino acids called the genetic code. The genetic code puts together protein in the cell which are used as the cells metabolism.
(Protein synthesis shown above)DNA technology 
(Recombinant DNA shown below)
Technology has come along way from the first microscope where bacteria, cells and much more where first seen and discovered.
(Recombinant DNA shown below)Technology has come along way from the first microscope where bacteria, cells and much more where first seen and discovered.
Now we can use our technology to modify or duplicate DNA. Recombinant DNA technology gives the ability for genes to be cloned. In order to do this a vector of DNA from two or more different sources is needed as well as a host cell to hold the genes. Normally plasmids in bacteria is used as a host because the plasmid is not apart of the bacterial chromosome and will replicate on its own. The new cell with the DNA of interest is put into the host. When the cell multiplies it makes genetically identical daughter cells that are same as the original donor. A specific DNA sequence can be cloned as well using a test tube. Polymerase chain reaction (PCR) quickly makes copies of a DNA sequence which has been used to “decipher the evolutionary history of human populations.”(Mader pg 459) From this DNA fingerprinting came about where by the number of short sequences that are repeated it can be determined what organism the DNA sample came from. Today this is used to identify from a blood or tissue sample found at a crime scene who the criminal was. DNA fingerprinting shows if a viral infection, genetic disorder, or cancer is present in an organism. Genetic engineering has become very useful over the years as well. Plants, animals, and bacteria are all genetically engineered to produce biotechnology products. Bacteria on plants are altered to produce frost-resistant plants. Plants can be engineered to resist harmful insects or herbicides.
(Genetically engineered corn to resist harmful insects shown below)
Cellular basic for cancers
Cancers can be inherited from your parents or grandparents in the form of a cancer
gene. Even though this a very common way, cancer is also caused by chemical’s called carcinogens. Tobacco is a major cause of cancer due to the chemicals added. To much exposure to UV rays from tanning, or radiation from x-rays can lead to cancer as well. A cancer cell is very distinct and looks nothing like a healthy cell. The nucleus is over sized and the entire cell is larger. Its also may contain an abnormal amount of chromosomes. A healthy cell divides 60-70 times and then dies.
This occurs because telomeres “protect the ends of chromosomes from DNA repair enzymes that always tend to bind together naked ends of chromosomes.” (Mader pg404) As cells divide telomeres get shorter and shorter until cells can not keep repairing themselves and die. In cancer cells telomeres is turned on so that they don’t get shorter which keeps the cancer cell alive not allowing it to die. As the cancer cell continues to divide they pile onto each other and cause tumors. Tumors that are incased in a capsule are benign tumors they continue to grow and don’t spread invading other parts of the body. When a tumor crosses over the membrane and invades lymphatic and blood vessels it has metastasis. Cancerous cells thenspreads to other parts of the body.
Early fetal development
During fetal development embryonic stem cells go through many cell divisions. Embryonic stem cells can become any kind of cell needed for a organism to develop fully for example organs, tissue, and bones. This process takes 9 months form conception. There are three stages of human development; pre-embryonic, embryonic, and fetal development. The pre-embryonic stage is the first week when fertilization occurs and cell division begins. The embryonic stage is the second week through the second month.(Above showns fetus at 4 weeks)
Fetal development takes place the third 
month through the ninth month. During 3-6 months the gender can be determined, the skeleton is visible, hair begins to grow, heartbeat can be heard, and the body is covered in a protective coating and with fine hair.
month through the ninth month. During 3-6 months the gender can be determined, the skeleton is visible, hair begins to grow, heartbeat can be heard, and the body is covered in a protective coating and with fine hair. (Right showns fetus at 4 months)
At the end of the seventh month the eyes open and if born its possible the baby will survive. In the last two months body hair is lost, body weight as fat under the skin is accumulated and the fetus rotates so that the head is pointing down towards the cervix getting ready for birth.
(Below is overview of all stages)
Role of genes/chromosomes in inheritance
Each individual has 23 pairs of chromosomes, 22 pairs of autosomes and 2 sex chromosomes. Alleles are in each pair of autosomes and are characteristic traits. Alleles are your genetic makeup like what your hair color is, eye color, height and if you have curly or straight hair. Each parent gives a set of alleles to daughter cells, each allele is either a dominant or recessive trait. Two recessive traits of the same kind is needed in order to dominate over a dominant trait. While only one dominate trait can take precedence over a recessive trait. Parents pass on dominant and recessive genes. Homozygous dominant means that the dominant gene is passed on and homozygous recessive means that the recessive gene is always passed on. The last possibility is that one or both parents
are heterozygous meaning that they could pass on either dominant or recessive genes. When genes are passed a set from each parent is given and then the dominant genes control what is passed on.This punnett square demonstrates how when genes are passed. The upper case B represents the dominant gene and the low case b represents the recessive gene. The genes along the top are from the mother parent and the genes along the left side are from the father. The genes inside the box are what are passed onto the child. In the square the B shows up three times in first position and the b only shows up once. In conclusion the B is the gene that is passed on to the child.
Work Cited
Mader, Sylvia S. “Human Biology” 10th ed. New York: McGraw-Hill, 2007
(mitosis)
(meiosis)
(Protein synthesis)
(recombinant DNA)
(genetic engineering)
(cancer cells)
(breast cancer)
(4 weeks)
(4 months)
(all stages)
(punnett square)
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