GeneticsYr10

= = = media type="custom" key="5730803" = = Genetics =

Why study Genetics ?


Your first task in this topic will be a debate...

Each person will be in a debating team. The class will be divided up into 6 groups of 3. When the first two groups are debating the other four will be judicators, time keeper, or audience. After the first debate the roles are reversed, until everyone has had a go.

The questions for debate is...

Given that the


 * human genome is now known,
 * diseases that may occur later in life can be tested for on unborn babies
 * insurance companies are offering lower rates for people who volunteer genetic information,
 * cloning has been achieved successfully on animals


 * should parents be able to choose their perfect child?
 * should cloning of humans be allowed?
 * should government health departments (or insurance agencies) have the right to keep a record of our DNA profile?

Before your debate... Look at a debating score sheet
 * 1) Check out the debate rules
 * 2) research the topic
 * Look up arguments for and against (it is good to know what the opposition will say and to have a counter argument)
 * Gather evidence to support your arguments.
 * 1) Develop a debating strategy[[image:debating_score_card.png width="387" height="553" align="right"]]
 * Look at similar debates
 * Should parents be allowed to select the gender of their offspring?
 * type 1: online
 * type 2: [[file:adjudicationSheet2.pdf]]



=Read the following news articles=
 * A woman has travelled to Thailand so that she can determine the sex the children she hopes to conceive through IVF.
 * In Germany it is possible to have IVF babies tested for genetic defects.

Discuss the moral issues involved in such decisions. How do you feel about this? When could genetic control be a problem? What safeguards could there be against the misuse of genetic manipulation?

=How much can you remember?= Download this file. Discuss the scenarios, first with your partner, then with the class. Write your answers. Save.



All of the information about us that we have not learnt through our lives is carried on an amazing molecule within the nucleus of our cells. It is called DNA (Deoxyribonucleic Acid). DNA stores its information by varying the order of four chemicals Adenine, ..... along its chain. The so called genetic code can be compared to the binary code (1 and 0) used by computers, except that it has four variants, not just two... so it is a lot more complex.
 * How does it all work?**



//Worksheet //
 * 1) visit  http://gslc.genetics.utah.edu/units/basics/tour/  and//
 * 2) complete the questions in the worksheet
 * 3) submit your finished work via email

Extracting DNA from kiwi fruit
//You can extract DNA from kiwi fruit or onions using chemicals that are in most people's kitchens. The following experiment breaks up the cells of the kiwi fruit and frees the DNA within them. The fruit juice is filtered and then dissolved in near freezing methylated spirits - this coagulates the DNA which can then be lifted out using a hook from a modified paperclip.//

Introduction
DNA is present in the cells of all living organisms. This procedure is designed to extract DNA from kiwi in sufficient quantity to be seen and spooled. This activity is ideal for students to work in pairs, but each student will have a tube of DNA at the end.

Some questions to get you thinking about the lab:
> All parts of the cell besides the DNA, i.e. cell wall (kiwi is a plant, after all), cell membrane, mitochondria, Golgi apparatus, endoplasmic reticulum, vacuoles, lysosomes, nuclear membrane, etc. > > Something to mush the cells (blender or your hands), something to destroy membranes (soap dissolves them), something to get rid of proteins and carbohydrates (salt causes them to precipitate), something to separate insoluble cell stuff from soluble DNA, and something to help get the DNA (alcohol precipitates it). > > Use it in DNA fingerprinting (solve a crime, see a genetic defect), put it into another organism to give it specific traits (this is called transformation or genetic engineering), other?
 * ====One way to purify a molecule is to get rid of everything but that molecule. If we want to isolate DNA from kiwifruit, what do we have to get rid of?====
 * ====What materials would you use to do that?====
 * ====What can we do with the DNA once we've purified it?====
 * [[file:Teacher guide.pdf]]
 * [[file:extraction dna kiwi student.docx]]
 * [[file:How to extract DNA from a kiwi fruit - Naked Scientists Kitchen Science 2006.pdf]]

//Naked Scientist - Kitchen science//

Answer these questions;

 * What do you think the soap solution does to the kiwi?
 * What does mushing the kiwi do?
 * What do you think the extraction solution is? What does it do to the kiwi?
 * Why do we cool the mixture?
 * What is being filtered out and what is going through the filter?
 * Why do we want the ethanol / methylated spirits as cold as possible?

// Amazing Fact!!! The DNA you have extracted has come from billions of kiwi fruit cells, which is why you can see it so easily. If you were able to unravel the DNA in just one human cell and stretch it out, it would be two metres long. However as DNA is so thin, you would not be able to see it without an incredibly powerful microscope.//

//To see an animated version of a DNA extraction performed with an onion, go to the// //Cambridge Hands on Science DNA extraction page.//

media type="youtube" key="WvsY0VcmJsY" height="385" width="640" align="center"

media type="custom" key="6633805" // Take photos of steps in your experiment for inclusion in your prac report .//



// Fill in this marking sheet and submit it with your assignment. // //Use it to find ways to improve your prac write ups in general.// //If your mark is reasonable, it will stick.// //Good luck!//



// ﻿ //

// HW Task: email answers to your teacher //

//1. What does DNA stand for?// //2. Which 4 bases make up DNA? Describe how they pair up to make this molecule// //3. How does the cell make a copy of a DNA molecule? Use a picture to help explain your answer.// //4. What are genes and what do they do?//

=
Deoxyribonucleic acid (DNA) is the single most important molecule in living cells and contains all of the information that determines what we are and what we look like. In essence, thy DNA molecule contains a chemical code that the cell uses to make proteins that are used by our bodies. ======



The DNA molecule, if we could see it, would resemble a very long spiral staircase, or a twisted ladder.[[image:dnabases.gif align="right"]]
The sides of the ladder are a linked chain of alternating sugar and phosphate molecules.

// The rungs of the ladder are joined to the sugar molecules and are composed of molecules called nitrogenous bases. // //While the sugar and phosphate molecules found in all DNA are the same, there are 4 different types of nitrogenous bases. // //These are adenine, thymine, guanine and cytosine (A, D, G & C) //

=
Each rung if the DNA ladder is made up of two different nitrogenous bases paired together. Because of there chemical nature, A will only pair with T and vice-versa; ======

G will only pair with C and vice-versa.

//Therefore, a single rung can only be one of four different structures - AT, TA, GC or CG). //

 These nitrogenous bases, paired along the rungs of the twisted DNA ladder, form a code of information. These codes provide information for the cell to produce chemical substances which help to manufacture our bodies.

Build a DNA model:
//In this activity, you will build a model of a DNA molecule, using coloured poster paper and/or pipe cleaners, etc. // // Your model should clearly show the sides of the ladder twisted into a spiral staircase. The rungs should also be clearly shown. // // Each rung should be labelled with the correct pairing of 2 of the possible 4 bases. There should be at least 20 rungs on your ladder. Make sure the rungs are not too close together as it will be difficult to twist your ladder. //

Cell division
//Online onion tip activity//

More genetics information


//University of Utah - Learn Genetics ....//

Gene Transcription and Translation


//You can think of the genetic code as a language. Each group of three bases or 'letters' forms a 'word' called a **codon**. Each codon specifies one amino acid, and proteins are made from long chains of amino acids. There are also codons that mark the start and end of the gene. // //<span style="font-size: 12px; line-height: 18px; margin-bottom: 15px; margin-left: 30px; margin-right: 30px; margin-top: 0px; padding: 0px;">But how is the code actually read? There are two stages in using the genetic code to make a protein. //

<span style="font-size: 12px; line-height: 18px; margin-bottom: 15px; margin-left: 30px; margin-right: 30px; margin-top: 0px; padding: 0px;">The template strand that codes for the protein makes mRNA using the base-pairing rules. There is one difference, however: thymine (T) is replaced with a new base, uracil (U).
 * <span style="font-size: 12px; line-height: 18px; margin-bottom: 15px; margin-left: 60px; margin-right: 30px; margin-top: 0px; padding-bottom: 2px; padding-left: 0px; padding-right: 0px; padding-top: 2px;">**Transcription**. The two strands of the helix separate and the sequence of bases in one strand - the template strand - is used to make a special 'messenger' chemical called **messenger RNA (mRNA)**.


 * **Translation**. In the second stage, the mRNA molecule is used as a template to build a protein. A structure called a **ribosome**'reads' the codons as it moves along the mRNA molecule. The ribosome is made from protein and another sort of RNA, ribosomal RNA (rRNA). Other RNA molecules, called **transfer RNA (tRNA)**, bind to the ribosome carrying the amino acid that matches each codon. The end result is a chain of amino acids - a protein.



Unraveling the code – Protein production.

 * <span style="font-family: Arial,Helvetica,sans-serif;">Proteins, for example enzymes and hormones, influence the cell’s activities, and consequently they will determine what the organism is like.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Proteins are made up of chains of amino acids.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Specific amino acids need to be linked in the correct order to produce the various protein.
 * <span style="font-family: Arial,Helvetica,sans-serif;">The amino acids are linked together by the ribosome (this is a very small organelle). This process is called translation.
 * <span style="font-family: Arial,Helvetica,sans-serif;">The ribosome knows which amino acids to link together by reading the code off the RNA (ribonucleic acid).
 * <span style="font-family: Arial,Helvetica,sans-serif;">The RNA is a copy of the DNA (deoxyribonucleic acid). The DNA remains in the nucleus. The copying of the DNA into RNA is called transcription.
 * <span style="font-family: Arial,Helvetica,sans-serif;">The DNA is a long molecule that makes up the chromosome. The shape of the DNA molecule is called a double helix (like a twisted ladder).
 * <span style="font-family: Arial,Helvetica,sans-serif;">Segments of the DNA molecule that contains the code for a particular characteristic, for example, hair colour or nose shape, is called a gene. Different genes are responsible for different characteristics.
 * <span style="font-family: Arial,Helvetica,sans-serif;">One chromosome may contain thousands of genes. The complete set of an individual’s genes is called its genome.

<span style="font-family: Arial,Helvetica,sans-serif; line-height: normal;">Gene regulation
//A<span style="font-family: Arial,Helvetica,sans-serif;">lmost all the cells in your body contain two copies of every gene. But your body contains many different sorts of cells, from muscle cells that help you move to cells in your eye that help you see. The cells are different because they make different proteins. //



<span style="display: block; font-size: 11px; line-height: 16px; margin-bottom: 15px; margin-left: 30px; margin-right: 30px; margin-top: 0px; padding: 0px; text-align: center;">//An example of a protein.// <span style="display: block; font-size: 11px; line-height: 16px; margin-bottom: 15px; margin-left: 30px; margin-right: 30px; margin-top: 0px; padding: 0px; text-align: center;">//Actin is formed from a number of smaller protein subunits and plays an important part in the contraction of muscle cells// <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: left;">Your body can make different sorts of cells using the same set of genes because it can control which genes are used to make proteins. In any cell at any time, some genes are switched on and some genes are switched off. A heart cell will make the proteins needed for a heart cell; a liver cell will make the proteins needed for a liver cell.

<span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: left;">Genes are switched on and off by other proteins called transcription factors, which stick to special control sites in the DNA at the start of a gene. These transcription factors are coded for by other genes - so genes are often controlled by the activities of other genes. Scientists think that maybe as much as 10 per cent of our genes are responsible for producing transcription factors.

Find out what kind of a rat mother you would be and how that would effect your baby's ability to recover from stress during the rest of its life!
<span style="display: block; font-family: arial,helvetica,sans-serif; text-align: left;">



Before you start this prac revise what you have learnt so far by flicking through the following powerpoint.





Prac: Looking at Cells (part 1)
__ Aim __ : To gain a first hand understanding of cell structure by isolating, mounting, staining and identifying single cells under a microscope. Through the identification of cell nuclei and the genetic material within them recognize these as the site where cell division occurs. To develop individual laboratory skills – in particular, how to use a compound microscope, isolate, mount, stain and accurately draw and label cells to scale. You have 15 min to complete each activity, then you must move to the next to give others a turn.



The following prac comes from the University of Boston//

[|Science Learning Network Home] / [|SLN Inquiry Resources] / © 1996 Museum of Science, Boston

Introduction[[image:microscope6.jpeg width="331" height="440" align="right" caption="Lab 101 - How to use a microscope" link="@http://www.doddhollow.com/biology/lab1.php"]]
Many samples, particularly cells, can appear quite transparent under the microscope. The internal parts of the cells, the organelles, are so transparent that they are often difficult to see. Biologists have developed a number of stains that help them see the cells and their organelles by adding color to their transparent parts.

While many biological stains are for advanced study only, there are some that are easy to obtain and use. Some readily available stains are: food coloring, iodine, malachite green (ick fish cure), and methylene blue. Food coloring can be found at a grocery store, and iodine can be found at a pharmacy. The last two stains, malachite green and methylene blue, can be purchased at aquarium shops.

Interestingly, certain stains color certain parts of a cell. Scientists choose specific stains when they want to look at a particular part of a cell. You can experiment with the stains listed above to see which parts of the cell each one colors.

Warning
Make sure you have an adult to supervise before you use stains. Stains not only add color to cells, but also hands, clothes, and nearly everything else. Use with caution and prepare your work area first with layers of newspaper.

Challenge
Stain cells and compare to unstained cells.

Tools & Materials

 * microscope
 * eyedropper
 * 2 flat slides
 * 2 cover slips
 * toothpick
 * cheek cells
 * stain (food coloring, iodine, malachite green or methylene blue)
 * paper towel
 * water
 * pencil
 * paper
 * eraser

Instructions
Before you begin, decide which stain you will use for the experiment.



Cells from the inside lining of your cheek are good for learning how to stain. Gently scrape the inside of your mouth with the flat side of a toothpick. This scraping will collect some of your cheek cells. (Don't worry, these cells are constantly being shed from your mouth so they will not be missed!) Place the cells on a flat slide and make a wet mount as you did in the "Wet mounts" activity. Now repeat this procedure so that you have two wet mounts of cells from the inside of your cheek. Now you need to add stain to one slide. To add stain, put a drop of the stain next to the cover slip on the slide and then draw it under the cover slip by placing a piece of paper towel against the other side of the cover slip. The paper towel will soak up the water, drawing the stain under the cover slip around the cell. Drawing the stain under the cell is called "wicking."

Look at the stained slide under the microscope. Draw what you see. Now look at the unstained slide under the microscope. Is it different? Draw what you see.

Prac part 2: Onion Skin Cells
<span style="font-family: Verdana,Arial,sans-serif; font-size: 12px; line-height: normal;">An __ [|onion] __ is made of many concentric layers. Each layer is separated by a thin skin or __ [|membrane] __. In this experiment you will make a __ [|slide] __ and look at the__ [|cells] __ of the membrane under a __ [|microscope] __.




 * 1) Take a small piece of onion and using [|forceps] ([|tweezers]) peel off the membrane from the underside (the rough side).
 * 2) Lay the membrane flat on the surface of a clean glass slide, and then add one drop of dye ([|iodine] or [|methylene blue]). Be very careful; these dyes will stain your skin and clothes.
 * 3) Using a pin, lower a thin glass [|cover slip] onto the slide. Make sure there are no air bubbles.
 * 4) Put the slide onto the stage of the microscope. Make sure the objective[|lens] is set on low power, and the microscope light is turned on.
 * 5) Look through the eyepiece lens and turn the focusing wheel until you can see the cells. They should look like lizard skin.
 * 6) Swap the objective lens for a high powered one so that you can see the cells at a greater magnification. You should be able to make out the nucleus.

Biology Corner Worksheets

Genetics project - Design a Species






Create an Imaginary Creature. The creature must have at least 6 genetic traits from the following list > 2 Single Allele Traits > 1 Codominant Trait > 1 Multiple Allele Trait > 1 Sex Linked Trait



1. Describe and Sketch each of the traits on the list, showing genotypes and phenotypes for each. (see sample) 2. Sketch two examples of your creature. The two examples must have different genotypes 3. Pick one of your single allele traits and and create a sample pedigree for your creature which includes at least 4 generations





Feel like a real world challenge... Sample work in a virtual fly
<span style="font-family: 'Comic Sans MS',helvetica,sans-serif;">.. complete as many questions as you can and hand them in with the species you have designed for grading.

virtual fruit fly lab





= Assessment =

Revision
media type="custom" key="6872081"


 * 1) ======Name the two groups into which most cells are separated.======
 * 2) ======What name is given to a sub-unit of a cell that has a specific function?======
 * 3) ======How does a virus survive?======
 * 4) ======What is the name given to the outer boundary of a cell?======
 * 5) ======The control centre of a cell is called its what?======
 * 6) ======Which organelle contains chlorophyll and absorbs sunlight?======
 * 7) ======In which organelle is energy produced?======
 * 8) ======In which organelle are proteins made?======
 * 9) ======What does DNA stand for?======
 * 10) ======Where do you find a cells DNA?======
 * 11) ======What name is given to the thread like structures which are composed of DNA?======
 * 12) ======Describe the structure of DNA.======
 * 13) ======Name the four bases that make up DNA and describe why they only pair with a parnter base they pair.======
 * 14) ======Name the two types of chromosomes.======
 * 15) ======How many chromosomes are located in a human skin cell?======
 * 16) ======How many chromosomes are located in a sperm cell?======
 * 17) ======What name is given to the position of a gene on a chromosome?======
 * 18) Explain the difference between the genotype and phenotype of an organism.
 * 19) Using hair colour as an example explain what an allelle is.
 * 20) What is a karyotype and how can it be useful in the detection of genetic disorders?
 * 21) What is the difference between meiosis and mitosis?
 * 22) What advantage could there be to an organism for meiosis to occur in the production of sex cells (eggs and sperm)?
 * 23) What characteristics of the fruit fly drosophila melanogaster make it particulary well suited to genetic research?
 * 24) Using black and white mice as examples, explain the difference between dominance, codominance and incomplete dominance.
 * 25) Colour blindness is a sex linked condition. Use a punnett square and family tree to show how colour-blindness can skip a generation.
 * 26) Why are some genetic conditions said to be sex linked?
 * 27) Explain what is meant by epigenetics and why this of interest to genetic researchers.
 * 28) Give a 50 word overview of a genetic condition that you have studied.
 * 29) When staining cells methylene blue is used to stain what component of cells?
 * 30) When staining cells iodine is used to stain what component of cells?
 * 31) How do DNA and RNA work together in running a cell?
 * 32) Questions from prac reports.
 * 33) Label a diagram of the cell undergoing translation and transcription.
 * 34) Chapter summary questions.

[|End of unit student survey]