Human Bio: Unit 1: Compendium Review pt 2 Genetics

Table of Contents

1. What is Genetics?
2. Chromosomes
3. DNA
4. RNA
5. Gene Expression
6. Early fetal development
7. Role of genes, chromosomes in inheritance
8. Recombinant DNA technology
9. Genetic Engineering
10. Mitosis
11. Cancer

1. What is Genetics?

Genetics is the science of genes. The Genes tell the body how to function, what to look like, and how to reproduce to put it simply. Genetics can also control ones likelihood to produce certain diseases, mental abilities, and natural talents. DNA found in chromosomes controls genetics.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, http://www.bionewsonline.com/a/what_is_genetics.htm, http://www.medhelp.org/medical-information/show/1217/Genetics, Human Biology 10th edition

2. Chromosomes

Chromosomes are molecules of DNA, or information for our bodies. They are millions of base pairs long. Chromosomes are organized and wrapped with proteins that give the chromosome a certain shape. The chromosomes are located in the nucleus of the human cell. However, the chromosome is not visible in the nucleus; the only time when it is visible is during cell division. Humans have 23 pairs of chromosomes, one of each from their parents.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://ghr.nlm.nih.gov/handbook/basics/chromosome

Chromosome

source: http://ghr.nlm.nih.gov/handbook/basics/chromosome

3. DNA

DNA, also known as deoxyribonucleic acid is the molecular brain of the body. It gives instructions to the cells. All the cells in the body have the same DNA. The order of the DNA’s four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T) dictate how the organism functions and reproduces. DNA has a structure known as a double helix, which are two strands wound in a spiral that make up the DNA, it looks like a twisted ladder. DNA reproduction is called replication and takes place when the two helixes split apart and each develops its second strand.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://ghr.nlm.nih.gov/handbook/basics/dna, http://www.eurekascience.com/ICanDoThat/dna_intro.htm

source: http://www.eurekascience.com/ICanDoThat/dna_intro.htm

source: http://ghr.nlm.nih.gov/handbook/basics/dna

4. RNA
RNA is very similar to DNA; the shape is the same, however it is normally a single strand. RNA can have several functions including interpreting information and making proteins through translation. There are 3 different kinds “(1) messenger RNA (mRNA) which is involved in the transmission of DNA information, (2) ribosomal RNA (rRNA) which makes up the physical machinery of the synthetic process, and (3) transfer RNA (tRNA) which also constitutes another functional part of the machinery of protein synthesis,” http://www.alsforums.com/definitions/rna.html.

a. RNA transcription

Transcription is when the DNA transfers information to make RNA. There are three stages in RNA transcription; they are initiation, elongation, and termination.

b. RNA translation

Translation is when the RNA makes proteins from the information found in the genetic code. Translation takes place on ribosomes.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://library.thinkquest.org/04apr/00217/en/biology/rna/index.html, http://geneticsevolution.suite101.com/article.cfm/what_is_rna, http://www.alsforums.com/definitions/rna.html

RNA molocule

source: http://geneticsevolution.suite101.com/article.cfm/what_is_rna

5. Gene Expression

Gene expression is the conversion of information gene first into messenger RNA and then to a protein. The information in one area is expressed to help the cell metabolism and function.

a. Regulation of gene expression

Cell metabolism is controlled by gene expression regulation. There are four different ways this can happen

I. Transcriptional control (happens in the nucleus)

II. Posttranscriptional control (happens in the nucleus)

III. Translational control (happens in the cytoplasm)

IV. Posttranslational control (happens in the cytoplasm)
Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition,
http://genome.wellcome.ac.uk/doc_WTD020757.html

picture of gene expression

source: http://geneticsevolution.suite101.com/article.cfm/what_is_rna

6. Role of genes, chromosomes in inheritance

Genes are what control the characteristics of offspring. If a child winds up with brown hair instead of blond, it will be because the brown was dominate. It is the dominant genes out of the chromosomes that are put together that dictate particular inheritance.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://genetics.gsk.com/chromosomes.htm

7. Recombinant DNA technology

rDNA is the product of two DNA strands fused together. The idea is to develop ways to fight and prevent genetic diseases, among many other medical applications. According to http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Projects00/rdna/rdna.html, “There are three different methods by which Recombinant DNA is made. They are
Transformation, Phage Introduction, and Non-Bacterial Transformation.”

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Projects00/rdna/rdna.html

8. Genetic Engineering

Genetic engineering is when interacting other DNA changes the DNA. It is used to make things healthier, less susceptible to diseases, more reactive to herbicides in the case of genetically engineered foods.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://www.safe-food.org/-issue/ge.html

9. Mitosis

Mitosis is cell division, how cells reproduce. This can be seen in the growth of tissue, tissue repair, or when the body has to replace old cells. Mitosis is always happening. Mitosis always creates two daughter cells. For mitosis the chromosomes replicate, copies line up a the center of the cell, the copies move to opposite sides and the cell membrane separates into two new cells. There are four phases of mitosis: prophase, metaphase, anaphase and telophase.

Mitosis

a. Prophase

The prophase is when chromosomes come together, the nucleus disappears and spindle fibers appear and attach to the centomome.

b. Metaphase

This is when the chromosomes line up at the center of the cell and the spindles become completely formed.

c. Anaphase
The sister chromatids separate and move to the poles.

d. Telephase

The Chromosomes reach their destination, the poles, the nucleus becomes visible, the spindle disappears and two daughter cells are formed.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th edition, http://www.wisegeek.com/what-is-mitosis.htm

10. Cancer

Cancer cells are lack individuality, serve no purpose to the body, they have abnormal nucleus’ that are enlarged and the number of chromosomes can be off. Cancer cells can endlessly divide, the can come together to form tumors.

Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th

Brain Cancer cell