GCSE AQA Biology. Genetic engineering

The AQA requires the students to understand genetic engineering and the advantages it can offer. The students need to ensure they know the process of inserting a gene into a bacterium.

The AQA specification states

”

d) In genetic engineering, genes from the chromosomes of humans and other organisms can be ‘cut out’ using enzymes and transferred to cells of other organisms.

e) Genes can also be transferred to the cells of animals, plants or microorganisms at an early stage in their development so that they develop with desired characteristics.

– new genes can be transferred to crop plants

– crops that have had their genes modified in this way are called genetically modified crops (GM crops)

– examples of genetically modified crops include ones that are resistant to insect attack or to herbicides.

– genetically modified crops generally show increased yields.

f) Concerns about GM crops include the effect on populations of wild flowers and insects, and uncertainty about the effects of eating GM crops on human health.”

So what is genetic engineering?

Is a scientific technique that changes the genetic material of an organism. The gene is taken from one organism and transferred to another. Genes from the chromosomes of a human cell can be ‘cut out’ using enzymes and is transferred to the cell of a bacterium.

The classic example of genetic engineering is Insulin production by bacteria using the human gene.

The basic principle is that the human gene for insulin creation is ‘cut out’ from human cell. This uses an enzymes that cuts out the gene ready to be inserted into a bacterium. The process is best summarised using a diagram.

 Source BBC Bitesize. Genetic engineering.

Transferring genes to both animals and plants.

Genes provide the instructions to make a particular protein. If a gene is inserted into an organism at an early stage of their development. As the organisms develops with the new desired characteristics from the other organism. Lots of examples of the use of genetic engineering can be found through a simple web search for example

Other benefits include

– creating the hormone insulin by genetically engineered bacteria.

– improve growth rate of plants and animals.

– crops normally have a larger yield.

– can be designed to grow in hot, dry or cold conditions.

– crop resistant.

New medicine “human engineering’

A growing field of medicine and science is genetic engineering. We are hopeful that diseases may be cured by placing healthy genes into cells. If this technique become possible it may be possible to cure children of life threatening illnesses and disease.

Problems with genetic engineering.

This is a new field of research “genetic engineering’ is both promising and poses many ethical issues. Some of the problems include

– hard to predict long term effects

– insects may become pesticide-resistant if they eat a constant diet of pesticide-forming plants.

– genes from genetically modified plants and animals might spread into the wildlife of the countryside

– GM crops are often infertile, which means farmers in poor countries have to buy new seed each year.

– Ethics of designer babies.

The big bang theory and science.

The sitcom “The Big Bang Theory” is funny, it has gained a bit of a cult status. Many teenagers watch it and find it cool as do many adults. The premise of the show focuses on the lives of 4 physicist based in California, these characters are stereotypical of the nerdy scientist who are slightly emotionally dysfunctional, ultra smart, interested in sci fi and gaming who work and are friends together. The script uses many scientific terms and ideas. For example “that was a valid hypothesis”   The scenes often contain science posters and diagrams and in the end we are meant to think that these characters are cool, funny and likeable.

I have often asked myself if the sitcom is good for science education or is it bad? I thought it was probably worth making a list.

Good

1. Makes science appear cool
2. Raises the profile of scientists
3. Uses scientific terminology and language (scientific literacy)
4. Article for Guardian

Bad

1. Portrays scientists as nerds and at times dysfunctional
2. Makes the audience appear that scientists are men
3. Ignores the hard work and effort required to be a scientist.
4. Article against Discovery blog – Big bang

I still have not decided the impact it actually has, I am sure that it does have some impact. I am not going to stop watching the show even if I am blogging whilst watching it.

Stats

I am predicting that the stats for the site will drop for the next month or so due to the domain name change but I hope that it improves the site in the long run.

We now have a proper name.

projectscientific.com is live. Same idea just with a home.

Reflecting on learning

I am watching a good video explaining evolution works which can found at How Evolution works . It takes about 7 minutes and explains evolution. I am considering how an animation has changed/ evolved the process of learning.

Twenty years ago we would not have had this technology available as a learning resource. Students would have relied on reading books, listening to the radio, watching tv programmes and being taught by a person. The process was perhaps slower in terms of information delivery. I wonder if we learn quicker now or perhaps our learning and understanding has changed. It is easier to find information quicker through a quick search reducing the need for using the mind as a knowledge source and allowing it to process and conceptualise information in a different way. I wonder….

Anyway the video is good… Watch me.

This website is interesting..

Random science videos and facts on memolition.com

Processing, understanding and learning text.

It is interesting how students often lack the ability to take a piece of text to read and process it. To then be able to understand it and recall/learn it. A skill that helps is to provide students with a piece of text that is linked to the topic being covered. To ask the students to read it a couple of times. To tell them to turn the text over and to write all that they can remember from it. Then to look at the text and to make bullet point notes or a flow diagram of the data. Give them time to assimilate it. Have a class discussion about what it means and check their understanding. Tell them to cover up notes again and to write what they can remember.

When they get used to this process it is amazing how much they take in and learn both in terms of recall but also understanding. The next lesson start them off by asking them questions based on recalling the work.

AQA. GCE Human Biology. Unit 1. Enzymes.

Enzymes – heroes and villains

Because of their high sensitivity and specificity, enzymes may be used as analytical reagents. The use of glucose oxidase and peroxidase in testing for glucose.

Enzymes are becoming more and more widely used in medicine. Enzymes are highly specific and sensitive to change. Enzymes can be used as analytical reagents – analytical agents are used to analyse (discover) what is in a substance or mixture and/or its concentration. The example that AQA refers to is the test for glucose – glucose in the urine is a classic test for diabetes. If glucose can be detected in the urine effectively then the patient can undergo further treatment. It is a classic example of an analytical tool.

So how does the glucose oxidase and peroxidase test for glucose in the urine?

We have established that urine of a person with diabetes may contain glucose. If the urine is tested with two enzymes, glucose oxidase and peroxidase the following reactions can be detected.

Glucose + oxygen ——> gluconic acid + hydrogen peroxide

The chemical Chromagen is also used. This is normally colourless. Peroxidase breaks down the hydrogen peroxide. The chromatin dye is then oxidised and become colourless.

colourless chromagen + hydrogen peroxide — peroxidase enzyme –> coloured chromagen + water

This test uses a glucose test strip. The strips contain the two enzymes and the Chromagen. The colour change indicates the level of urine change. More information

 

VIsitors

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Revisiting lactose intolerance

This post goes into more detail about lactose intolerance. To view it click here. 

I also found the following animation which gives an animation journey of lactose intolerance.