Epigenetics & The Environment

Identical Twins
-When twins are younger they have the same environment so the receive the same epigenome 
tags but when the grow older and do not share the same environment they receive different tags changing their appearance and molecular level.
-Environmental factors include: Physical activity, diet, exposure to toxins and stress
-Epigenetic tags are erased from mom and dads chromosomes during the first day of fertilization but some tags remain which are imprinted genes
Rats
-A high nurturing mother will raise a high nurturing pup. Does not matter who gave birth to it, just who raised it. It will become a relaxed rat. It may let down its guard too quickly and is more likely to be eaten by predators.
-Mothers activate the pups GR gene by licking them.
-Cortisol binds to the GR gene and the hippocampus sends out a signal to turn off the stress circuit and turns off the fight or flight response and cortisol production.
-When a child has low nurturing people in their childhood they are more likely to become a low nurturing person themselves. When a child has a high nurturing majority of people in their life than they will more likely become high nurturing. External factors can change the high/low nurturing in a person.
-Nutrition & The Epigenome
-The nutrients we get from from our food enter metabolic pathways where they are manipulated modified and molded into molecules that body can uses. It is responsible for making the methyl groups which are important epigenetic tags that silence genes 
- The mothers diet can cause critical changes that stick with you for the rest of your life. Lack of methyl-donating folate or choline during late fetal or early development causes certain areas of the genome to be under-methylated for life
Epigenetics &  The Human Brain
-Methyl influences gene expression by stabilizing it. High levels of methyl means less rRNA production which means fewer ribosomes which result in less protein production. 
-Toxins have a long term affect on the body.Some drugs work by changing gene expression. These changes stabilize through epigenetic mechanisms like DNA methylation, reversing the effects of the disease. 

DNA Fingerprint

DNA is unique for everyone. The only exception is if a person has an identical twin.
DNA fingerprints are used for identifying a biological mother/father to connecting a person to a crime.
The “crime” that was committed was a crime of confection. One of Jimmy's seven sisters licked his holographic lollipop.
The saliva found on the sucker, left by the the lick, will connect the criminal to the crime.
The restriction enzyme cuts the long DNA in different locations. Where it cuts depends on the code in the DNA molecule and the code in the enzymes.
Agarose gel is a thick, porous, jelly-ish substance.

Electrophoresis is the process of moving molecules with an electric current. When the

process is over the fragments are distributed in the gel depending on their lengths.

Smaller fragments of DNA move more easily than longer strands?

You need to place a nylon membrane over the gel to absorb the DNA because the agrose

Probes attach themselves to the DNA fragments on the nylon membrane. They attached only where their code encountered a certain sequence of code among the various fragments.

The probes are radioactive.





Based on the DNA fingerprint, Honey Sweet is the culprit of this crime.

Click on the Link “DNA Workshop” (if this link won't load, scroll down to the bottom where it says "try the non-java script version)
Once you’re there, go to the link “DNA Workshop Activity” and practice with DNA replication and protein synthesis.

Browse the DNA Workshop site.


At the DNA Workshop activity you can go through the DNA Replication and Protein Synthesis process.

Find an Article about DNA

Go to http://www.thegenesite.com/

15. Read an article about genetics at this site that you might find interesting, or use the "Search" box in the upper right hand corner to search for DNA fingerprinting.

Title of Article __What is DNA?__ Author and Date _____December 5, 2010_______

Summarize what the article was about. Write this in a paragraph format.

DNA is the hereditary material in humans and almost all other organisms. Almost every cell in the body has the same DNA. DNA bases become pairs, A with T and C with G, to become units called base pairs. Each base is also attached to a sugar molecule and phosphate molecule. These components together become a nucleotide. Nucleotides are organized in a couple of long strands that form a double helix. The structure of the double helix is almost like a ladder. DNA can replicate and copy itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. It is important when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.

Mitosis

1. Which stage does the following occur
Chromatin condenses into chromosomes: Prophase
Chromosomes align in center of cell.: Metaphase
Longest part of the cell cycle.: Interphase
Nuclear envelope breaks down.: Prometaphase
Cell is cleaved into two new daughter cells.: Cytokinesis
Daughter chromosomes arrive at the poles.: Telophase

Watch the video carefully.

2. The colored chromosomes represent chromatids. There are two of each color because one is an exact duplicate of the other.

--How many chromosomes are visible at the beginning of mitosis?: Four

-- How many are in each daughter cell at the end of mitosis?: Eight

--The little green T shaped things on the cell are: Centriole

-- What happens to the centrioles during mitosis? In the process of mitosis, during the interphase, the centrioles divide.

3 . Identify the stages of these cells:
Metaphase
Cytokinesis
Prophase

Another Mitosis Animation
Go to www.johnkyrk.com/mitosis.html

View the animation and describe the cell in:
Prophase
Centrioles move to the opposite sides of the cell and a spindle fiber network is created. The chromatin condenses into chromosomes and the nucleus fades.

Metaphase

The spindle fibers cause tension that causes a single plane of chromosomes on the metaphase plate.

Telophase
The daughter chromosomes disperse to the poles and the spindle fibers disappear. The nuclear envelope disappears.

Onion Root Tip

Onion Root Tip and White Fish

Genetics Reflection

Johann Gregor Mendel. Is considered to be the father of genetics. Genetics are characteristics and traits passed down from parent to offspring, that is why children often look like their parent(s). Genes come in pairs from both parents, genes do not blend. The Law of Dominance says the organism with different forms of genes will bring forth a form that is dominant. Every trait is determined by a gene pair, and each trait has two forms. Visible traits are called phenotypes but each form of a trait are an allele. A pair of alleles create a genotype. The Law of Independent Assortment explains that genes that hold different traits are organized separately from each other so that no other inheritance is not affected. In a gene pair, the dominant gene will appear rather than the recessive gene. But if there is a pair of recessive genes then the recessive gene occurs.

A "gamete" is a cell that fuses with another cell during fertilization. Offspring are conceived when parental gametes are coupled. Each parent contributes a gamete. A way to keep track of the alleles and gametes is by using the Punnett square.

Cells are the basic unit of life. Robert Hooke discovered square-like bodies in a cork which were actually cells. In each cell the nucleus carries hereditary material; a nucleus is a dark body in a cell.
Mitosis is a natural event the occurs started when one mother cell has two daughter cells. When an organism is not going through mitosis it is in the inter phase.
The steps of mitosis:
Interphase
Prophase
Metaphase
Anaphase
Telophase- During this phase the nuclear material is doubling